class-9 - edusys · 4 / class 9 eduheal foundation ... titis, rabies, aids, tb, polio; pulse polio...

Class-9

CLASS ‐ IX S. No. Topic Page No.

1. Syllabus Guide Line 04

2. Story of Chromosomes 07

3. The Basis and Basics of Life 14

4. Genetic Changes and Old Biotechnology 16

5. Biological Processes and Old Biotechnology 22

6. Biological Weapon 25

7. Xenotransplants 27

8. DNA Computer 29

9. Biotechnology Today and Tomorrow 35

10. The First Commercial Use of Genetic Engineering 42

11. Milestones from Test Tube Baby (Human) to Cloned Baby (Sheep) 45

12. Biotechnology & Biodiversity 47

13. Biotechnology to Improve Biodiversity 50

4 / Class 9 E d u h e a l F o u n d a tio n

Ques t ions Higher yields What do we do to get higher yields in our farms? How Biotechnology plays a key role in this?

Material in our clothing What kinds of clothes help us keep cool? Why do wet clothes feel cool?

Different kinds of materials In what way are materials different from each otther? Is there some similarity in materials? In how many ways can you group the diifferent materials you see around? How do materials and gases differ from each other? Can materials exist in all the three states?

What are things made of? What are the various types of chemical sub stances?

Do substances combine in a definite man ner? How do things combine with each other? Are there any patterns which can help us guess how things will combine with each other? How do chemists weigh and count particles of matter?

What is there inside an atom? Can we see an atom or a molecule under a microscope or by some other means? What is there inside an atom? What is nanotechnology? What is nanobiotechnology?

Key concepts Plant and animal breeding and se lection for quality improvement, use of fertilizers, manures; protec tion from pests and diseases; organic farming.

Cooling by evaporation. Absorption of heat

All things occupy space, possess mass. Definition of matter

Solid, liquid and gas; characteristics – shape, volume, density; change of state – melting, freezing, evapo ration, condensation, sublimation

Elements, compounds and mix tures. Heterogeneous and homogeneous mixtures. Colloids and suspensions. Equivalence – that x grams of A is chemically not equal to x grams of B.Particle nature, basic units: atoms and molecules. Law of constant proportions. Atomic and molecular masses. Mole concept. Relationship of mole to mass of the particles and numbers. Valency. Chemical formulae of common compounds

Atoms are made up of smaller par ticles: electrons, protons, and neu trons. These smaller particles are present in all the atoms but their numbers vary in different atoms. Isotopes and isobars.

Activities/ Processes Collection of weeds found in fields of dif ferent crops; collection of diseased crops; Discussion and studying composting/vermi composting

Experiments to show cooling by evapora tion. Experiments to show that the white objects get less hot.

To feel the texture, observe the colour and lustre, effect of air, water and heat, etc. on each of the materials Sorting out a medley of materials, in vari ous ways. Observe shape and physical state of differ ent materials. Observe effect of heat on each of the re sources. (Teacher to perform the experi ment for camphor, ammonium chloride and naphthalene.)

Discussion on claims ‘Air is a mixture’ (mix ture of what? How can these be separated?), ‘Water is compound’ and ‘Oxygen is an el ement’. Titration using droppers or syringes, quan titative experiments. Discussion on the fact that elements com bine in a fixed proportion through discus sion on chemical formulae of familiar com pounds. Simple numericals to be done by the stu dents. A game for writing formulae. e.g. criss cross ing of valencies to be taught through divid ing students into pairs. Each student to hold two placards: one with the symbol and the other with the valency. Keeping symbols in place, Teacher to move only valencies to form the formula of a compound.

Brief historical account of Rutherford’s experiment. Charts, films etc.

CLASS IX

Statements given in italics are related to biotechnology. The syllabus guideline given is only indicative & not exhaustive.

Class 9 / 5 E d u h e a l F o u n d a tio n

Biological Diversity How do the various plants around us differ from each other? How are they similar? What about animals? How are they similar to and different from each other? What is biodiversity and how Biotechnol ogy is useful in preserving it?

What is the living being made up of? What are we made up of? What are the different parts of our body? What is the smallest living unit?

How do we fall sick? What are the various causes of diseases? How can diseases be prevented? How can we remain healthy? What are edible vaccines? What are vaccines and how Biotechnol ogy helps in their production?

How do substances move from cell to cel l? How do food and water move from cell to cell? How do gases get into the cells? What are the substances that living organ isms exchange with the external world? How do they obtain these substances?

Motion How do we describe motion?

Force and Newton’s laws What makes things change their state of motion?

Diversity of plants and animals – basic is sues in scientific naming, Basis of classifi cation, Hierarchy of categories/groups, Major groups of plants (salient features) (Bacteria, Thallophyta,Bryophyta, Pteridophyta, Gymnosperms and Angiosperms). Major groups of animals (salient features) (Nonchordates up to phyla and Chordates up to classes).

Cell as a basic unit of life; Prokaryotic and eukaryotic cells, multicellular organisms; cell membrane and cell wall, cell organelles: chloroplast, mitochondria, vacuoles, ER, Golgi Apparatus; nucleus, chromosomes – basic structure, number. Tissues, organs, organ systems, organism. Structure and functions of animal and plant tissues(four types in animals; meristematic and permanent tissues in plants).

Health and its failure. Disease and its causes. Diseases caused by microbes and their pre vention Typhoid, diarrhoea, malaria, hepa titis, rabies, AIDS, TB, polio; pulse polio programme.

Diffusion / exchange of substances between cells and their environment, and between the cells themselves in the living system; role in nutrition, water and food transport, excretion, gaseous exchange.

Motion – displacement, velocity; uniform and nonuniform motion along a straight line, acceleration, distancetime and veloc ity time graphs for uniform and uniformly accelerated motion, equations of motion by graphical method; elementary idea of uni form circular motion.

Force and motion, Newton’s laws of mo tion: inertia of a body, inertia and mass, momentum, force and acceleration. El ementary idea of conservation of momen tum, action and reaction forces.

Discussion on diversity and the char acteristics associated with any group

Observation of model of human body to learn about levels of or ganization – tissue, organ, system, and organism, observe blood smears (frog and human), cheek cells, on ion peel cell, Spirogyra, Hydrilla leaves. (cyclosis). Survey which diseases have vaccines and which do not.

Surveying neighbourhood to collect information on disease occurrence pattern. Studying the life cycle of the mosquito and malarial parasite. Discussion on how malaria is spread, how to prevent mosquito breeding.

Looking at closed and open stomata, plasmolysis in Rhoeo leaf peels

Analysis of motion of different common objects. Drawing distancetime and velocitytime graphs for uniform motion and for uniformly accelerated motion

Demonstrating the effect of force on the state of motion of objects in a variety of dailylife situations. Demonstrate the change in direc tion of motion of an object by ap plying force.


Gravitation What makes things fall? Do all things fall in the same way?

Work, energy and power How do we measure work done in moving anything? How does falling water make a mill run?

Floating bodies How does a boat float on water?

How do we hear from a distance? How does sound travel? What kind of sounds can we hear? What is an echo? How do we hear?

HOW THINGS WORK NATURAL PHENOMENA NATURAL RESOURCES

Balance in Nature Why do air, water and soil seem not to be consumed? How does the presence of air support life on earth? How have human activities created distur bances in the atmosphere? How does nature work to maintain balance of its components? What key role BT is playing in maintaining ecological balance

Gravitation; universal law of gravitation, force of gravitation of the earth (gravity), acceleration due to gravity; mass and weight; free fall.

Work done by a force, energy, power; ki netic and potential energy; law of conser vation of energy

Thrust and pressure. Archimedes’ , buoy ancy, elementary idea of relative density.

Nature of sound and its propagation in vari ous media, speed of sound, range of hearing in humans; ultrasound; reflection of sound; echo and sonar Structure of the human ear (auditory aspect only)

Physical resources: air, water, soil Air for respiration, for combustion, for moderat ing temperatures, movements of air and its role in bringing rains across India. Air, water and soil pollution (brief intro duction) Holes in ozone layer and the probable dam ages. Biogeochemical cycles in nature: water, oxygen, carbon, nitrogen

Analysis of motion of ball falling down and of ball thrown up Measuring mass and weight by a spring balance

Experiments on body rolling down inclined plane pushing another body. Experiments with pendulum Experiments with spring Discussion

Experiments with floating and sink ing objects.

Experiment on reflection of sound.

Case studies of actual situation in India with more generalized over view of inter relationship of air, water, soils, forests. Debates on these issues using re sources mentioned alongside, visit to/from an environmental NGO; discussion.


We can learn a lot by looking at chromosomes! They can tell us everything from the likelihood that an unborn baby will have a genetic disorder to whether a person will be male or female. Scientists often analyze chromosomes in prenatal testing and in diagnosing specific diseases. What are chromosomes and why do we need them? Chromosomes are compact spools of DNA. If you were to stretch out all the DNA from one of your cells, it would be over 3 feet (1 meter) long from end to end! You can think of chromosomes as “DNA packages” that enable all this DNA to fit in the nucleus of each cell. Normally, we have 46 of these packages in each cell; we received 23 from our mother and 23 from our father. (If you want to have some more basic knowledge you can read the lower standards Biotechno activity book) Why do chromosomes look like this? Chromosomes are very small but can be specially prepared so we can see them using a microscope. Chromosomes are best seen during mitosis (cell division), when they are condensed into the fuzzy shapes you see here. Chromosomes taken from dividing cells are attached to a slide and stained with a dye called Giemsa (pronounced JEEM-suh). This dye gives chromosomes a striped appearance because it stains the regions of DNA that are rich in adenine (A) and thymine (T) base pairs. Why do scientists look at chromosomes? Scientists can diagnose or predict genetic disorders by looking at chromosomes. This kind of analysis is used in prenatal (before birth)

Story of Chromosomes


testing and in diagnosing certain disorders, such as Down syndrome, (Condition when one have 47 chromosomes) or in diagnosing a specific type of leukemia. Such diagnosis can help patients with genetic disorders receive any medical treatment they need more quickly.

How Do Scientists Read Chromosomes?

To “read” a set of human chromosomes, scientists first use three key features to identify their similarities and differences:

1. Size. This is the easiest way to tell two different chromosomes apart.

2. Banding pattern. The size and location of Giemsa bands on chromosomes make each chromosome pair unique.

3. Centromere position. Centromeres are regions in chromosomes that appear as a constriction. They have a special role in the separation of chromosomes into daughter cells during mitosis cell division (mitosis and meiosis).

Using these key features, scientists match up the 23 pairs — one set from the mother and one set from the father.

What are centromeres for?

Centromeres are required for chromosome separation during cell division. The centromeres are attached to microtubules, which are proteins that can pull chromosomes toward opposite


ends of each cell (the cell poles) before the cell divides. This ensures that each daughter cell will have a full set of chromosomes.

Normally, each chromosome has only one centromere.

The position of the centromere relative to the end of the chromosome helps scientists tell chromosomes apart. Centromere position can be described three ways: metacentric, submetacentric or acrocentric.

In metacentric (pronounced met-uh-CEN-trick) chromosomes, the centromere lies near the center of the chromosome.

Submetacentric (pronounced SUB-met-uh-CEN-trick) chromosomes have a centromere that is off-center, so that one chromosome arm is longer than the other. When chromosomes are aligned, they are oriented so that the short arm, designated “p” (for petite), is at the top, and the long arm, designated “q” (simply for what follows the letter “p”), is at the bottom.

In acrocentric (pronounced ACK-ro-CEN-trick) chromosomes, the centromere resides very near to one end.

Making a Karyotype

A karyotype is an organized profile of a person‛s chromosomes. In a karyotype, chromosomes are arranged and numbered by size, from largest to smallest. This arrangement helps scientists quickly identify


Hint : while matching take into account the size of chromosome and position of Centromere


Disease occur in a person who have something different, such as.

• Too many or too few chromosomes? • Missing pieces of chromosomes? • Mixed up pieces of chromosomes?

To understand how our cells might end up with too many or too few chromosomes, we need to know how the cells normally get 46 chromosomes.

First we need to understand meiosis. Meiosis is the cell division process that produces egg and sperm cells (gametes), which normally have 23 chromosomes each.

If eggs and sperm only have one set of chromosomes, then how do we end up with 46 chromosomes? During fertilization, when the egg and sperm fuse, the resulting zygote has two copies of each chromosome needed for proper development, for a total of 46.

Fertilization


Sometimes chromosomes are incorrectly distributed into the egg or sperm cells during meiosis. When this happens, one cell may get two


copies of a particular chromosome, while another cell gets none. What happens if a sperm or egg cell with an abnormal number of chromosomes participates in fertilization? It depends on how many chromosomes the gamete has. For example, if a sperm with an extra chromosome fertilizes an egg with a normal chromosome number, the resulting zygote will have 3 copies of one chromosome. This is called trisomy (pronounced TRY-so-mee)

What to look for in a karyotype? When analyzing a human karyotype, scientists first look for these main features: Are there 46 chromosomes? 1. Are there 2 identical pairs of each autosome and 2 sex

chromosomes? 2. Are there any rearrangements between chromosomes or large

deletions? What we can‛t see in a karyotype? Although our chromosomes tell us a lot, they can‛t tell us everything! Things we can‛t see in a karyotype include: 1. Individual DNA strands or genes. 2. The number of genes in any given area of a chromosome. 3. The presence or location of small mutations. (Scientists cannot

predict diseases caused by small mutations within genes).


What‛s the Secret Behind Biotechnology? Take a look at your hands, your hair, your eyes. Examine the roots of an onion, the leaf and branches of a tree, the mold growing on bread. Observe the colorful plumage of a peacock, the nose of your pet dog, the gills and fins of a fish. All of these are made up of amazing cells — the foundation of life and the key to biotechnology. Tiny, units called, cells do all the work an organism needs to survive, like breathing (or metabolism), giving protection against foreign microscopic bodies, and growing. Some organisms are just one-celled, like yeast or bacteria. Most organisms are much more complex — made up of billions of cells joined together like lace or a honeycomb. Cells are usually specialized, just as some people are teachers, others farmers and others scientists. Cells in different parts of the organism may have different jobs and may contain different substances. Organisms grow by adding more cells. For instance, the trunk of a tree becomes wider as new layers of cells form new rings each year.

What‛s Cooking or What Do Recipes Have to Do With Biotechnology? Clearly, there are a tremendous number of cells that constitute most types of organisms. However, constituting an organism is not simply a random act of mixing up different cells. Just as preparing a dish is not simply an ad hoc affair, but a careful combination of certain ingredients according to a recipe, so organisms are constituted out of elaborate recipes: which elements to produce, in what amounts, when to introduce them, etc.

The Basis and Basics of Life


Every cell within an organism contains the complete recipe book with all of the instructions required to assemble and sustain life in that organism. However, any individual cell within the organism will only read the recipes necessary for the functioning of that particular cell. For instance, there are genes in a Red Delicious apple that instruct the cells in the skin to produce its bright red color. Each organism has its own unique book of instructions which leads to the great diversity of life on earth. These instructions (or genes) are passed on from generation to generation. Suppose we have one apple that is sweet but green and another that is red but sour. It is possible to combine the two and produce a variety of apple which is red and sweet. For that matter, we can produce one that is green and sour. We have created new varieties of apple by trading genetic information (This is called genetic engineering). Another way of thinking about this is that we often use ingredients of one recipe in another. Of course, the result is not always tasty or what we might expect. In the same way, we cannot be sure of the results when we combine genes except after much trial and error.


We looked at how organisms are made up of cells. In those cells are combinations of instructions or recipes guiding their work. As succeeding generations of organisms are produced, new combinations are formed. These are genetic combinations formed naturally. Now we will examine how this genetic change comes about. Genetic change occurs naturally through a process known as natural selection and mutations. Alternatively, different combinations can also be achieved through human intervention. Did you know that broccoli, cauliflower, cabbage, and sprouts all came from one species of a wild mustard? This amazing variety would probably not have occurred if not for human intervention. These interventions are what biotechnology is about. For our purpose, let us define biotechnology as: The use of biological organisms, systems, or processes to make or modify products that are useful to us. Biotechnology can be characterized as old and new. What is being referred to as Old Biotechnology does not imply that it is out of date. It simply refers to the methods of manipulation that have existed for centuries. On the other hand, New Biotechnology refers to the techniques which developed with the discovery of DNA and to applications in new areas that have not been understood previously.

How do we “manipulate” these changes and processes? What are the limitations of our efforts? Why do we do so? What are the benefits and the risks of our interventions?

Genetic Changes and Old Biotechnology


Natural Changes in Genetic Information How can we tell that genetic changes are natural? Let us take a look at family trees. It is easy to see how a line of similarity runs through our families. At the same time, there are also clear differences. Changes in genetic information are natural and occur at random. In sexual reproduction, virtually millions of genetic combinations are possible. Thus, it is reasonable that within one family, there can be much genetic variation in terms of physical traits and even preference traits.

Through successive generations, considerable genetic variation can occur naturally. Over time, new varieties or species evolve when there are changes in the genetic code. Nature allows for this through two processes: natural selection and mutation.

Natural Selection: Genetic Changes Taking Their Time

Natural selection is what happens when species which have the traits that help them adapt to the environment survive and reproduce. Their genes get passed on to the next generation.

This can be examplified by the classic tale of natural selection among the English Peppered Moth or the Biston betularia.

The light gray, spotted variety of a moth (peppered moth) used to be in abundance in the English countryside. They were camouflaged when resting against a backdrop of light-colored lichen. In contrast, the dark-winged variety made easy targets for predators. However, with the Industrial Revolution at the turn of the 19th century, factories


were built on a large scale, producing unprecedented levels of pollution which killed the lichen on the rocks. As a result, the dark-winged moths were better able to blend in with their surroundings, while their spotted cousins stood out and were driven close to extinction.

Evolutionary changes may occur gradually over millions of years: new generations differ in small details from the previous ones. Evolution may also take giant leaps with dramatic changes occurring in just several hundred or thousand years.

In either case, clearly, we would not be able to observe or gain much genetic variation in our lifetime.

Mutations: Random Changes in Genetic Information

However, we can and do observe genetic variation in nature. This is possible because genes sometimes mutate. As you know that every organism has its own unique recipe book of genes that ultimately determines what traits an individual organism has.

Cells divide to make more cells. This is how organisms grow. In this process, DNA is copied. Mutations are the rare mistakes made during copying. Suppose we tried to copy the recipe for cupcakes but by mistake, noted 1 spoon of salt instead of 1 spoon of sugar, we would get a different result.

Usually mutations cause little harm. However, sometimes, mutations can cause disease, e.g. cancer. At other times, new traits result that

Two Varieties of peppered moth


can actually benefit the organism. For instance, some insects are resistant to pesticides because of mutations in their genes. So, they survive and breed a new generation of insects with this resistance.

Or think of why we need to finish a course of antibiotics when we have a throat infection, usually 7 days. If we stopped the treatment after 4-5 days, infection may reoccur. This time, there is a chance that new bacteria, which has mutated, may be resistant to the antibiotics, rendering it ineffective.

Mutations happen by chance and at random points of the DNA chain. They can also result from radiation, exposure to certain chemicals like dioxin, tobacco, and UV radiation. Mutations are an important natural source of genetic variation. They can contribute to an increase in the chances of survival for a species.

Selective Breeding: Selected Changes in Genetic Information

Selective breeding involves cross-breeding closely-related species, usually through the normal reproductive means. Just think of the champion horses specially bred for their speed or even our pet dogs.

With plants, it is possible to cross- breed using cuttings and other asexual means. This ancient


practice uses the whole or some substantial part of an individual organism.

This practice may also be referred to as artificial selection, as opposed to natural selection. People select the individual animal or plant that has a certain trait useful to human beings, for example, strength or quick growth rate. These individuals form the breeding stock and new generations with these traits can be bred.

We should note that selective breeding is in fact a form of genetic manipulation because we are selecting organisms that have those genes we want, giving them a greater chance of being reproduced. In this way, we modify the original species.

Activity : Me and My family Tree Materials

• colored pencils or crayons or pens Purpose of Activity : Use this activity to discuss natural genetic

changes over time.

Students choose 4 colored markers. With: ∙ Color 1—circle all the physical traits that are similar from the

child to the other family members on the page.


∙ Color 2—circle all the preference traits (likes) that are similar from the child to others on the page.

∙ Color 3—put a box around physical traits that are different. ∙ Color 4—put a box around preference traits that are different. Discussion ∙ How are you like your parents and grandparents? ∙ How are you like your brothers and sisters? ∙ How are you different from your family members? ∙ What does this mean? Explain that over time, there are natural genetic changes. Changes can occur within one generation or more gradually over many generations.


Probably you may know, that fermentation is a process that has been harnessed to produce a number of foods that we enjoy today, e.g. cheese, yoghurt, etc. Before we study the significance of fermentation in biotechnology, let us first understand how it occurs in natural settings.

So What is Fermentation?

One of the basic jobs cells do is to produce energy constantly. To do this, cells break down the food taken by the organism. In most organisms, a key component of this process is oxygen. However, there is also a kind of back-up system that will provide energy if oxygen is missing.

This system or process is known as fermentation. Fermentation is one method by which organisms, including human beings, derive their energy for living when oxygen (O 2 ) is lacking. Normally, when oxygen is plentiful, the cells of most organisms break down sugars and starch from food to release carbon dioxide (CO 2 ), water (H 2 O), and energy.

When oxygen is insufficient, cells in organisms switch to the fermentation process to provide that energy. Our body cells are also able to switch to fermentation, e.g., during strenuous exercise, when we cannot take in oxygen quickly enough. Like the normal process, fermentation also breaks down sugars, releasing carbon dioxide (CO 2 ) and energy. In addition, depending on the type of fermentation, lactic acid or alcohol is produced. These are the two most common types of

Biological Processes and Old Biotechnology


fermentation naturally occurring in nature. Our muscle cells produce lactic acid during fermentation. This causes the pain that we feel in our muscles.

Using Biological Processes: Harnessing Single-celled Organisms to Work

Various foods such as vegetable and fruit juices will ferment when left on their own. Invisible to the eye, single-celled microorganisms such as yeast and bacteria are at work, breaking down the sugar molecules present.

When we deliberately introduce living organisms into our bread, milk, and apple juice, we are applying biotechnology to food production. Indeed, sugars in the dough, juice, and milk are food for these microscopic organisms. The carbon dioxide and lactic acid or alcohol are really waste products for these organisms but are useful for human beings.

How is Fermentation by Microorganisms Useful?

Different types of yeasts or bacteria used will yield different by- products, providing variety to our tastes. We can obtain different wines and beers depending on the type of bacteria or yeast we use. In baking, it is the CO 2 that makes the dough rise.

Fermented products also last longer. The fermentation process preserves foods. This is why fermentation was a popular preservation method in the days before refrigeration.

Yeast causes fermentation of sugar and produces

alcohol and CO 2


Limitations

Fermentation technology has its share of limitations, a few of which are listed below. 1. Remember that microbes such as bacteria and yeast are living

organisms. Just like other organisms, they require a specific environment in order to survive and function. For instance, the temperature, oxygen levels, acidity levels, amount of nutrients, etc., need to be closely monitored.

2. Toxic by-products may result. 3. Considerable waste may be produced. 4. To obtain pure products, caution is needed to avoid contamination

or to ensure that no anti-microbial reactions will occur.

ACROSS: 1. Act of supplying water to fields (10) 6. Farmers do this to the excess water

to make the fields’ drier (5) 7. This makes your cup of milk sweeter

(5) 8. Cold substance used to preserve

things (3) 10. Planting of seedlings (3) 12. Mycorrizhae fungi are added to this

part of the plant (5) 14. Chemicals found in most fertilizers (7) 15. Plant seedlings are covered with this

to keep the birds away (3)

DOWN: 1. of your country (6) 2. Cut the crops (4) 3. Inheritance (8) 4. ____ culture: mass cloning method

(7) 5. Something added to the soil to get the

better yield (10) 9. Biological poisons (5) 11. The most important crop of the Green

Revolution in India (5) 13. This part of the shoot is used to obtain

a large number of plantlets (3)

Search for Answers!

crossword Puzzle


Biological Weapon

Anthroax bacillus : A bioweapon which was in news a few years back

Anthrax enters thru skin

Enters thru intestines

Enters thru lungs

Massive outpouring of ruptured vessels, mucosal edema and necrotic (dead tissue) lesions

Leads to local edema and necrotic (dead tissue) lesions

Macrophage

Anthrax bacillus Factors affecting virulence

capsule exotoxins

other factors Regional Lymph Node

Inflammation and bleeding in lymph system Spreads to lymph

and blood system

invades/poisons blood Lung and lymph

blockage

water in the lungs

death death

shock death

meningitis

spore

Every coin has two sides. This is true for biotechnology also. Biotech- nology is producing lots of things for the welfare of human being but on the other side it is also being used in a bad way. One of the example is Bioweapon. Biological weapons are toxic materials produced from pathogenic organisms (usually microbes) or artificially manufactured toxic substances that are used to intentionally interfere with the biological processes of a host. These substances work to kill or incapacitate the host. Bio- logical weapons may be used to target living organisms such as humans, animals or vegetation. They may also be used to contaminate nonliving substances such as air, water and soil. Bioweapons Agents There are a variety of microorganisms that can be used as biological


Microbe Natural Habitat

Target Host

Mode of Contraction Diseases/Symptoms

Anthrax Bacillus anthracis

Soil Humans, Domestic Animals

Open Wounds, Inhalation

Pulmonary Anthrax Septicemia, Flulike symptoms

Clostridium botulinum* Soil Humans

Contaminated Food or Water, Inhalation

Weakness, Double Vision and Vertigo, Difficulty in Speaking, Swallowing, and Breathing, Muscle Weakness

Clostridium perfringens

Intestines of humans and other animals, Soil

Humans, Domestic Animals

Open Wounds Gas gangrene, Severe Abdominal Cramps, Diarrhea

RICIN Protein toxin

Extracted from Castor Bean Plants

Humans

Contaminated Food or Water, Inhalation, Injection

Severe Abdominal Pain, Watery and Bloody Diarrhea, Vomiting, Weakness, Fever, Cough, and Pulmonary Edema

Smallpox Variola Virus

Eradicated from Nature, Now Obtained from Laboratory Stockpiles

Humans

Direct Contact with Bodily Fluids or Contaminated Objects, Inhalation

Persistent Fever, Vomiting, Rash on Tongue and in Mouth, Rash and Bumps on Skin

weapons. Agents are commonly chosen because they are highly toxic, easily obtainable and inexpensive to produce, easily transferable from person to person, can be dispersed in aerosol form, or have no known vaccine. A list of a few potential biological organisms that may be used as biological weapons is given in the table.

While it is possible to develop biological weapons from microbes, finding a means of distributing the substances is difficult. One possible way is through aerosols. This can be ineffective as the materials often get clogged when spraying. Biological agents distributed by air may also be destroyed by UV light or rain may wash them away. Another method of distribution may be to attach the toxins to a bomb so that they may be released upon explosion. The problem with this is that the microbes will most likely be destroyed by the explosion as well.

* one drop of its toxin is enough to kill millions of peoples


What is a xenotransplant?

A xenotransplant is a transplant between species. Transplanted organs are called grafts, hence a xenograft is an organ transplanted from one species to another.

What is a species?

The barrier that defines a species is whether reproduction is possible. A dog and a pig cannot mate and successfully produce offspring, therefore they are a different species and a transplant from one to the other would be called a xenotransplant.

A collie and a labrador retriever can mate and produce offspring, therefore they are the same species and a transplant from one to the other would not be called a xenotransplant.

A transplant between two genetically different members of the same species is called an allotransplant. A transplant between members of the same species that are genetically identical (inbred animals or identical twins) is called an isotransplant. And a transplant from one person to themselves (for example moving bone from the hip to the back to fix a broken vertebra) is called an autotransplant.

What xenotransplants have been done?

“Baby Fae”, a child born with a malformed heart survived for a short period of time with a baboon heart. Two men were transplanted with

Xenotransplants


livers from baboons at the University of Pittsburgh. These patients lived for several weeks. And in late 1995 a man with AIDS was transplanted with the bone marrow of a babboon. Which organism is considered and why? Pigs are considered the most suitable species as a source of material for xenotrans plantation for several reasons: • they reproduce quickly and have large

litters; • their organs are similar in size to those of humans; • they are easy to rear

in conditions free of particular pathogens (d i se ase -ca us i ng organisms);

• the risk that they will carry pathogens that can infect humans is smaller than with nonhuman primates (apes and monkeys); and

• they can be genetically manipulated to reduce the risk of rejection. Currently xenografts are not very successful compared to allografts. However, the shortage of organs has prompted continued research into this area. Thousands of people die each year due to the shortage of human organs.

Baby Fae


Microprocessors made of silicon have eventually reached their limits of speed and miniaturization. Chip makers need a new material to produce faster computing speeds. You won‛t believe where scientists have found the new material they need to build the next generation of microprocessors. Millions of natural supercomputers exist inside living organisms, including your body.

DNA (deoxyribonucleic acid) molecules, the material our genes are made of, have the potential to perform calculations many times faster than the world‛s most powerful human-built computers. DNA might one day be integrated into a computer chip to create a so-called biochip that will push computers even faster. DNA molecules have already been harnessed to perform complex mathematical problems.

A DNA computer is a molecular computer that works biochemically. It “computes” using enzymes that react with DNA strands, causing chain reactions. The chain reactions act as a kind of simultaneous computing or parallel processing, whereby many possible solutions to a given problem can be presented simultaneously with the correct solution being one of the results.

DNA Computer


There are several advantages to using DNA instead of silicon:

• As long as there are cellular organisms, there will always be a supply of DNA.

• The large supply of DNA makes it a cheap resource.

• Unlike the toxic materials used to make traditional microprocessors, DNA biochips can be made cleanly.

• DNA computers are many times smaller than today‛s computers.

DNA Molecule High Storage Capacity, high parallelism

Biochemical tools high parallelism

Miniaturization &

Integration

Conventional computer two bit computation, serial, irreversible properties

Answer to Crossword Puzzle


IF YOU HAVE PROBLEMS, DISSOLVE

THEM…..

AS COMPUTER COMPONENTS SHRINK YEAR BY YEAR SCI- ENTISTS DREAM OF THEIR ULTIMATE GOAL. A CHEMICAL COMPUTER, WHOSE WORKING PARTS WOULD BE INDI- VIDUAL MOLECULES.

BUT THIS HAS REMAINED ONLY A DREAM-UNTIL NOW. LEONARD ADLEMAN OF THE UNIVERSITY OF SOUTHERN CALIFORNIA HAS JUST SHOWN HOW TO DO COMPUTATION USING DNA.

ADLEMAN, A COMPUTER SCIENTIST, CHOSE A TASK THAT REPRESENTS A WHOLE CLASS OF HARD-TO-SOLVE PROBLEMS. COMPUTER GUYS CALL IT THE TRAVELING SALESMAN PROBLEM.

COULDN‛T YOU CALL IT SOME- THING A LITTLE LESS GENDER BIASED….A LITTLE MORE NOW?

IN THIS VERSION, THE MARKETING REP* HAS A MAP OF SEVERAL CITIES WITH ONE-WAY STREETS BETWEEN SOME OF THEM. THE PROBLEM IS TO FIND A ROUTE (IF IT EXISTS) THAT PASSES THROUGH EACH CITY EXACTLY ONCE, WITH A DES- IGNATED BEGINNING AND END.

TOO CORPORATE! HOW ABOUT THE HAMILTONIAN

PATH PROBLEM?

HOW ABOUT THE MOBILE MARKETING

REP PROBLEM?

WHEN THE NUMBER OF CITIES IS LARGE – SAY MORE THAN 100-THIS PROBLEM IS TOO MUCH FOR EVEN THE FASTEST COMPUTER.

* REP = representatvie

Adleman and Discovery of DNA Computer


HE REPRESENTED EACH CITY CHEMICALLY BY A SINGLE STRAND OF DNA 20 BASES LONG ITS SEQUENCE CHOSEN AT RANDOM.

FOR HIS DNA COMPUTATION, ADLEMAN CHOSE THIS SIMPLE ARRANGEMENT OF 7 CITIES AND 19 STREETS.

THE ACTUAL SEQUENCES

DON‛T MATTER!

A STREET BETWEEN TWO CITIES IS THE COMPLEMENTARY 20 BASE STRAND THAT OVERLAPS EACH CITY‛S STRAND HALFWAY. THIS STREET LITERALLY JOINS THE TWO CITIES.

IN DNA C ALWAYS PAIRS WITH G AND T ALWAYS PAIRS WITH A. SO IN CLOSE-UP IT LOOKS LIKE THIS.

NOTE: SOME CITIES MY BE

VISITED MORE THAN ONCE.

A MULTICITY TOUR BECOMES A PIECE OF DOUBLE-STRANDED DNA, WITH THE CITIES LINKED IN SOME ORDER BY THE STREETS.

ADLEMAN TOSSED A FEW GRAMS OF EVERY DNA CITY AND STREET-WELL OVER 100 TRILLION MOLECULES – INTO A TINY TEST TUBE.

ALL THOSE MOLECULES COMBINED LIKE MAD, MAKING MULTIPLE COPIES OF EVERY POSSIBLE PATH IN AN INSTANT.

OW! GOT DNA IN MY EYE!


THE COMPUTATION WAS DONE, BUT WHERE WAS THE ANSWER! SOMEHOW THE PATH THAT VISITS EACH CITY ONCE HAD TO BE EXTRACTED!

Well?

THE LAB WORK TOOK ABOUT A WEEK.

THIS LAB WORK IS

WET ? AND IT WORKED! IN

THE END, ADLEMAN HAD PURE DNA THAT ENCODED THIS 7-CITY TOUR!

USING CHEMICAL TECHNIQUES, ADLEMAN FOLLOWED THESE STEPS. 1. EXTRACT ALL PATHS GOING FROM

‘START‛ TO ‘END‛. 2. OF THOSE FIND THE ONES PASSING

THROUGH 7 CITIES. 3. OF THOSE ISOLATE PATHS WITH 7

DIFFERENT CITIES. 4. IF THERE‛S ANYTHING LEFT AFTER

STEP 3, DECLARE IT THE WINNER.

ONE SECOND TO DO THE COMPUTATION, 600,000 SECONDS TO GET THE OUTPUT!

WHAT DOES IT MEAN, THIS MIRACULOUS MARRIAGE OF COMPUTER SCIENCE AND MOLECULAR BIOLOGY?

THIS IS THE GREAT- EST THING SINCE SLICED BREAD!!

SLICED BREAD GOES STALE

FASTER THAN UNSLICED

BREAD…

THIS EXPERIMENT WAS ONLY A SMALL BEGINNING AND ALREADY SCIENTISTS ARE EXTENDING THE IDEA TO MORE AND BIGGER PROBLEM.

ANY PROBLEM REQUIRING A BRUTE FORCE

SEARCH OF ALL POSSIBLE SOLU-

TIONS.


ADLEMAN DIVISIONS DNA COMPUTERS WITH TRILLIONS OF PROCESSORS

WORKING IN PARALLEL – SO NOW SOMEONE HAS TO INVENT SOME TRILLION-PROCESSOR SOFTWARE.

And then-

HE NOTES THAT CHEMICAL COMPUTERS WOULD CONSUME ALMOST NO ENERGY OR DESK SPACE.

NOW WHERE IS THAT TEENY-WEENY

KEYBOARD?

ADLEMAN ALSO WORKS TO ENCOURAGE BIOLOGISTS TO

THINK ABOUT DNA PROCESSES IN TERMS OF COMPUTATION.

HOW HAVE COMPUTATIONAL FACTORS ALREADY AFFECTED GENETICS AND EVOLUTION?

WHAT NEW TRICKS CAN WE COAX DNA TO DO?

LEN WAKE UP!

TIME FOR YOUR JOB,

MS. LOMAN.

AND THE EFFECT ON MARKETING MAY BE INCALCULA- BLE.


Sparked by the understanding of how cells and living processes work, biotechnology presents us with new ideas to: • increase efficiency in the production of food and other substances, • enhance the quality of products, • improve the quality of life, and • reduce environmental hazards. “New” biotechnology began to develop in the 1970s especially with: 1. the advance of DNA research, and 2. learning how microbes are useful in

many new applications. Keep in mind that biotechnology is a broad term for a number of methods which manipulate cells and genes. Our text will focus to what is commonly known as genetic engineering or recombinant DNA (rDNA) techniques and also take a second look at fermentation technology.

The Promise of DNA Research How would you like tastier French fries, low in fat and calories? What about tomatoes that are juicy, red, flavorful and remain firm and fresh as well? If you were a farmer, what would you say about crops resistant to pests, diseases, frost and drought? And gives high yields as well? Suppose you suffered from diabetes, or cancer and you could get a cure?

Biotechnology Today and Tomorrow


How can biotechnology do all this? Recall that all organisms, whether bacteria or the extinct dinosaur, use the same molecule — DNA — to store genetic information. Since the genetic language is universal, it is possible to cut and paste pieces of genes. Actually, genes being “cut” and “glued” together again can happen naturally at random, when our cells divide to make more cells and DNA is being produced.

Application of recombination DNA technology for species improvement

1. Isolation of plasmid DNA and DNA containing gene of interest

2. Gene Inserted into plasmid

Bacterium Cell containing gene of interest

Plasmid Bacterial chromosome

Recombinant DNA (Plasmid)

3. Plasmid put into bacterial cell

Gene of interest

DNA of chromosome

Recombinant bacterium

4. Cells cloned with gene of interest

5. Identification of desired clone

Coples of protein product isolated

Human growth hormone treats stunted growth

Protein dissolves blood clots in heart attack therapy

6. Various applications

Gene used to alter bacteria for cleaning up toxic waste

Gene for pest resistance inserted into plant

Copies of gene isolated and transferred to other organisms


Scientists can also do this intentionally. This is known as recombinant DNA (rDNA) technology or genetic engineering. The idea is to persuade the original DNA molecule to adopt and integrate a new gene so that it yields a new trait or product. With recombinant DNA technology, scientists can do what nature has not done: 1. recombine genetic information of different species; like gene of

firefly can be combined with orchid to form bioluminescent orchid. 2. by-pass the natural reproductive cycle to transfer genetic

information, thereby speeding up the process of “cross-breeding”; and

3. unlike traditional cross-breeding or selective breeding, rDNA is very specific—introducing one gene will usually not affect the development or functioning of the rest of the organism.

Let us look at two ways in which this technology is being used: First, desired genes can be directly inserted into the cells of host plants or animals. Inserted genes usually make something happen. For example, a gene can be introduced into a crop which will produce a substance toxic to targeted pests when eaten. The crop is then said to be pest- resistant. Inserted genes can also stop something from happening, for example, a gene has been introduced into a tomato that prevents it from becoming soft while ripening. This allows the fruit to stay firm, making it easier to transport. Second, desired genes are introduced via another organism.


Very often, it is difficult or too expensive to directly introduce genes into a complex organism. Scientists have a technique to add these genes to bacterial or viral cells instead, and hope that some of them will adopt the new genes. Bacteria multiply very quickly, so scientists can find those that have adopted the new gene and breed them separately in a bacteria culture. The result: the new gene has been cloned, i.e. the bacteria create copies of themselves.

As already mentioned genes are like recipes for specific products. So if we are able to clone the gene, we can mass produce desired products. One example of this is the pioneering production of human insulin, a hormone used to treat diabetes. This was the first commercial application of recombinant DNA technology in 1977. Bacteria with the new gene started to produce insulin, which can then be easily extracted and purified.

Today, recombinant DNA technology has many applications, especially in agriculture and medicine.

Limitations

1. Although recombinant DNA technology overcomes some of the limitations of selective breeding, there is no guarantee that the inserted gene will go on to produce the desired product or trait even if it is adopted by the host. We can say that this is an “internal” means of regulating biotechnology.

2. Organisms that have new genes may not be permanent solution to problems. For instance, we can genetically modify some plants to produce certain toxins against pests. However, these pests can in time develop new varieties that are resistant to these toxins.


The “New” Fermentation In biotechnology, the term fermentation is actually used to refer to the process of generating large numbers of microbes such as bacteria. The idea is that when these microbes are placed in a suitable environment, or fermenter, where nutrients are kept adequate, they will multiply. This is the process of cloning microbes. Greater numbers of microbes can produce more desired products. Fermentation may seem rather unsophis- ticated when we think of baking bread or brewing beer. However, scientists are finding new applications for this age-old technology. One such application is the production of biofuels. These are made from plants. Fermentation of some plants produce alcohol, just like in wine-making. For example, sugarcane and corn when fermented produce the alcohol called ethanol. Ethanol is a biofuel that can be used as a substitute for gas. In some countries like Brazil, all the cars run on ethanol or a petroleum-ethanol mixture. Another application of fermentation is in the manufacture of bioplastics. Bacteria that make plastics similar to polyester are added to huge fermentation vats (vessel where fermentation takes place) where they feed on crops such as sugarcane. The plastics that are created as a by product can be used to make shampoo bottles and disposable razor holders. However, sometimes, it is not so much the products of fermentation that is sought, but the microbes themselves. The production of the insulin hormone combines both genetic engineering with the fermentation process. As discussed earlier, the human gene responsible for insulin production is introduced into bacteria. These bacteria are then allowed to mul-

Bacteria used to ferment alcohol

Oh surel when the beer is finally ready to drink, they throw us away!

Saccharamyces carvei


tiply in a vat containing nutrients. As a result, the bacteria containing the gene are cloned and insulin can be produced in large quantities. Limitations The limitations of using fermentation biotechnology in these new applications are essentially the same as those in old applications. Despite the variety of products that can be made, fermentation processes depend on the work of those single-celled organisms like bacteria and yeast, which live in specific environments. Risks and Benefits Just like in old biotechnology, there are concerns about health risks, environmental impacts, and product quality. New biotechnology does not take away these concerns. Indeed, some people fear new biotechnology while they would not think twice about selective breeding. New Biotechnology Speeds Change Perhaps one of the basic reasons for concern is simply the speed of change. Selective breeding also involves the manipulation of nature but the results take several years to show. In the time taken, whole societies can adapt and may even adopt the process as a part of their culture. Recombinant DNA technology, however, can offer results almost immediately. Thus, there is a sense that we lack control and security. Indeed, with old biotechnology, anyone can apply it and control the process. With new biotechnology, this responsibility lies almost exclusively with scientists, industrialists and policy makers. Is Biotechnology Safe? Further, since new biotechnology often involves bacteria and viruses, there is a concern that accidental release may be difficult to deal with since they can multiply very quickly and can be a risk to health. Scientists are aware of the health risks since they deal with the microbes in their work. Often, they try to make use of microbes


which are commonly found and which they know a lot about. How about genetically modified foods? Rigorous procedures would have to be in place to ensure quality and safety to consumers. In general, biotechnology is a highly controlled process with genetic modifications introduced one at a time and outcomes systematically monitored. Regulation of quality and safety are conducted by government agencies, corporations, and, among the scientific community. We can say this is an “external” means of regulating biotechnology.

IN THE MARKET: BIOTECH OLD AND NEW Today Tomorrow

Baby whole carrots Seedless minimelon Tomatoes that stay fresh up to two weeks Sweeter peas and peppers HighLaurate Oil a raw material used in soaps, detergents and cocoa butter replacement fats

LowSaturate Oil a healthier salad and cooking oil from rapeseed plants

Bststimulated Milk A growth hormone called Bst has been introduced in cows to stimulate milk production. A gene with the recipe for Bst was inserted in bacteria.

Colored Cotton colorproducing genes from bacteria are introduced in cotton genes. This will mean fewer dyes are needed, reducing environmental pollution.

Eggs vaccinated while still in the shell against a common virus

Salmon fastergrowing salmon

Insulin a hormone for diabetics, who are unable to produce the hormone to break down sugar. Produced by geneticallyengineering bacteria.

Tissue Plasminogen Activator (TPA) a natural human protein that dissolves blood clots, used when a heart attack occurs, allowing blood to flow. Used currently in hospitals but patients may be able to use it themselves one day.

Hepatitis B Vaccine AIDS Vaccine Aspire a biofungicide used on citrus fruits, berries, and grapes to prevent postharvest rot. It is a naturally occurring yeast, harmless to non targeted organisms.

Insectprotected corn and potato genetically improved plants to control the corn borer and the potato beetle

Methane gas a biogas that can be obtained from microbial fermentation of domestic, agricultural, and industrial wastes

WHAT DO YOU THINK?


Recombinant DNA technology was first used commercially to produce human insulin from bacteria. In 1982, genetically engineered insulin was approved for use by diabetics. People with certain types of diabetes inject themselves daily with insulin, a protein hormone that regulates blood sugar.

Insulin is normally produced by the pancreas, and the pancreases of slaughtered animals such as swine or sheep were used as a source of insulin.

To provide a reliable source of human insulin, researchers obtained (from the human cells) DNA carrying the gene with the information for making human insulin.

Researchers made a copy of DNA carrying this insulin gene and moved it into a bacterium.

The control of all the normal activities of a bacterium depends upon its single chromosome and small rings of genes called plasmids. In genetic engineering pieces of chromosome from a different organism can be inserted into a plasmid. This allows the bacteria to make a new substance.

The First Commercial Use of Genetic Engineering

Location of Pancreas in human Body


You need to know the steps of this process.They are: =The gene the genetic engineers

want may be in a human chromosome. It might be the gene for insulin production.

= They use an enzyme to cut the insulin gene out of the chromosome.

= Plasmids are then removed from bacterial cells

= The plasmids are cut open with an enzyme

= A human insulin gene is inserted into each plasmid

= The genetic engineers encourage the bacteria to accept the genetically modified plasmids

= Bacteria with the insulin gene are then split from one cell into two cells, and both cells got a copy of the insulin gene. Those two microbes grew, then divided into four, those four into eight, the eight into sixteen, and so forth. With each cell division, the two new cells each had a copy of the gene for human insulin.

And because the cells had a copy of the genetic “recipe card” for insulin, they could make the insulin protein. In the way, special strains of Escherichia coli (E. coli) bacteria or yeast given a copy of the insulin gene can produce human insulin.

Genetic engineering is used for the production of substances which used to be both expensive and difficult to produce. In addition to the fact that genetically engineered bacteria are able

Human cell

isolated plasmid

plasmid cut with enzyme

Gene inserted in plasmid

plasmid with gene inserted in bacterium

production of insulin

reproduction of bacteria+ plasmids

suitable bacterium

gene responsible for controlling formation of insulin

sliced up chromosome

Chromosomes


to produce as much insulin as is needed, there are other advantages. Some of these are: = purifying insulin from the pancreas of slaughtered cattle and pigs

was slow and expensive. = its production from genetically modified bacteria is both quick and

relatively cheap = some patients were allergic to animal insulin = some patients did not like using a product from slaughtered ani-

mals = the insulin produced by bacteria as a result of genetic engineering

is pure human insulin. Other examples of Geneticaly engineered include: = antibiotics such as penicillin = various vaccines for the control of disease

Activity : Genetic Engineering Here is the DNA of a plant that contains the gene for blue flowers (plant A), a plasmid, and a plant that normally has white flowers (plant B), but we want them to be blue. Cut out the DNA for each organism. 1. Remove the DNA for blue

pigment from plant A. Describe in scientific terms what you are doing.

2. Insert the ‘blue‛ gene into the plasmid DNA. Describe in scientific terms what you are doing.

3. Cut plant B DNA and insert the ‘blue‛ gene into it. Describe in scientific terms what you are doing.


1978 Louise Brown, the first test tube baby, was born. She was conceived in a test tube via in vitro fertilization.

1978 Genentech Scientists became the first genetic engineering company to clone the gene for insulin.

1980 Swiss researchers introduced a gene for human interferon into bacteria and then cloned millions of cells to produce an inexpensive and abundant supply of this previously rare protein. This was the first big success story in the commercial production of drugs by genetic engineering.

1980 The United States Supreme Court granted the first patent to Ananda Chakrabarty for a genetically engineered life form, a microbe to consume oil spills in the ocean.

1981 The United States Patent Office granted a patent for onco- mouse. This is a mouse made transgenic with human genes that predispose it to cancer for use in medical research.

1982 The first genetically engineered drug, a form of human insulin produced by bacteria approved.

1984 Alec Jeffries developed a DNA fingerprinting method at the University of Leicester by using individual unique sequences of DNA.

1984 British scientists mixed goat and sheep embryo cells and implanted them into a surrogate animal. This led to the birth of the first chimera, a cross between a goat and a sheep.

Milestones from test tube baby (Human) to Cloned Baby (Sheep)


1986 Field trials of transgenic crops, many designed to be herbi- cide-resistant, began around the world, thereby exposing the natural ecosystem to the introduction of engineered genes.

1986 The first genetically engineered vaccine for hepatitis B for humans approved.

1990 W. French Anderson and others conducted the first gene therapy on a four-year-old girl suffering from a rare immune system disorder.

1994 The U.S. approved the commerical use of bovine somatropin, also known as bovine growth hormone. This hormone increases the production of milk in cows, and became one of the first genetically engineered products available to farmers.

1995 Duke University researchers announced the transplant of hearts from genetically altered pigs into baboons.

1996 Genzyme Transgenics announced the birth of a goat carrying BR-96 monoclonal antibodies to be used experimentally to deliver conjugated anticancer drugs to humans.

1997 Hunt Willard and others created the first artificial human chromosome, opening the door to designer babies.

1997 Stanley Prusiner earned the Nobel Prize for his pioneering work on prion diseases such as Bovine Spongiform Encephalopathy, which is thought to have caused the outbreak of mad cow disease in Britain and Creutzfeldt-Jakob disease.

1997 A sheep named Dolly was cloned. 1998 Dolly gave birth to Bonnie, a lamb conceived by conventional

means. The birth offered reassurance that cloned animals like Dolly can develop into healthy animals capable of reproducing.


The value of biodiversity is in its magnitude and its evolving nature. It is a huge store of differences that can be called upon for survival in different and changing environments. Through every asexual reproductive process where mutation occurs and each sexual reproductive process, biodiversity is increased – so biodiversity is increasing every second of the day wherever life occurs even as you read this page. However, as quickly as biodiversity is naturally increased in this way, it is being axed by human impacts as well as naturally occurring changes.

Since life began on earth, biodiversity has been naturally increased. Suppose life began with just a handful of different kinds of single cell life forms in what has come to be called a primordial soup. Let us, just to get a grasp of this, say there were about 20 different mono- cellular life forms at this point. There would have been millions of these organisms, but only twenty different kinds just like for example there are millions of dogs on earth today but only a few different

Biotechnology & Biodiversity

Natural creation of Biodiversity

Mountain of Biodiversity

Natural degredation of biodiversity

Human caused degredation of biodiversity


breeds. As these 20 different forms underwent mutations as they divided to reproduce, they created more different ones so after say 5 significant mutations that were not lethal. Now we have 25 different forms. This would have been the first step in increasing biodiversity on earth. Now instead of only 20 different kinds of organisms to choose from on earth there were 25. Of the 5 new forms, some could occupy new environments.

Activity : How biodiversity in the Peppered Moth saved it from extinction

Normally the Biston betularia (the peppered moth) that one would see today flitting about, is a white moth with black speckles. Their colouring allows them to be camouflaged against the white barked birch trees that they rest on. However, these moths emerge after pupating in a range of pigmentations from pitch black to snow white and all shades in between. In some towns in England, the pollution that occurred as a result of industrialization dirtied the birch tree bark. White peppered moths decreased in number (they were easy for predators to see) but black peppered moths became more common.

1. If we were to apply the symbols of the story in the background information to this true situation, what would they represent?


2. As towns introduced legislation to clean up the air, trees got lighter and again the white moths became more common and black moth numbers decreased. In this reversal, which of these symbols would change and what will they be changed to?


Agriculture (including crops, fishery, forestry and animal husbandry) must feed an ever increasing human population forecast to reach 8000 million by 2020 AD, of which about 6700 millions will be in developing countries. With finite resources and an increasingly vulnerable environment, it is highly important that growth in efficiency rather than in number should be the dominant factor in the doubling of global output of plants and livestock products. To meet future needs and to be able to sustain agricultural production, agricultural research and its applications will have to use all available technologies, especially the rapidly developing modern biotechnologies. The convention on Biological Diversity defines biotechnology as “any technological application that uses biological systems, living organisms or derivatives thereof, to make or modify products or processes for specific uses.” I. REPRODUCTIVE TECHNOLOGIES 1. Artificial insemination (AI) This is where semen is taken from a

male, divided into doses by man in sterile conditions and then manually inserted into a female of the same species. There is no contact with the male and semen can be used sparingly to cover several females. In developed countries, AI is being developed and used in the breed development of sheep, horses and pig genetic resources.

Biotechnology to Improve Biodiversity


AI technology offers certain specific advantages, especially (a) widespread use of outstanding males and dissemination of

superior genetic material; (b) progeny testing under environment and managerial conditions

to improve the rate and efficiency of genetic selection;

(c) accelerated introduction of new genetic material by import of semen rather than live animals and thus, reducing the international transport costs;

(d) enabling the use of frozen semen even after the donor is dead; and

(e) reducing the risk of spreading sexually transmitted diseases.

Long-term semen storage, without loss of viability, for use in AI, is another valuable technology for promoting conservation of endangered breeds of farm animal species, although this technology has the disadvantage of preserving only half genotypes and requiring secure cryopreservation facilities.

2. Embryo Transfer (ET)

If good stocks of male and female individuals of a livestock species are left to breed naturally, the process can be very slow and taxing on the female. If however females can be covered and the resulting embryos removed and inserted into less valuable females, more high quality progeny can be generated with out the good females ever having to be pregnant. Embryo transfer and other associated reproductive technologies have been successively used


for rapidly multiplying the populations of elite breeds of cattle, buffalo, sheep, goat, horse and pig. ET schemes are especially recommended for some specialized purposes, viz., a. rapid expansion of rare and/or improved exotic/local genetic stocks

of farm animals and even elite female animals b. reducing the cost of international transport by shipping embryos

rather than living animals in which case quarantine restrictions would also apply;

c. the rapid replacement of existing genotypes by using ET rather than grading up through repeated crossing; and

d. the possibility of increasing the twinning rate by combining AI with the transplanted embryo.

Other advantages of ET technology are a. sex determination before birth b. control of sexually transmitted diseases c. using biological diversity of embryos and d. environmental adaptability as compared to transport and

establishment of imported animals. In combination with other animal biotechnological procedures, ET techniques can accelerate herd development and animal conservation especially of rare genetic stocks. 3. Embryo cryopreservation

Freezing of semen and embryo is an established commercial practice especially in cattle. This technique


is useful as a conservation strategy for endangered breeds, and every effort should be made to select embryos representing the maximum range of current diversity. Preservation of embryonic stem cells could represent an important method of genome conservation.

4. IVF (In Vitro Fertilization) Embryo Production

Here female egg cells and sperm are mixed in a laboratory for fertilization to take place. The fertilized egg are then developed in a nourishing medium until they are developed enough to be implanted into females of the same species. These females then carry the embryo through pregnancy and give birth to the offspring. The birth of such in vitro animals was reported in cattle, goat, pig and buffalo.

5. Sexing semen and embryos (determining gender)

It is possible now to extract one cell from an early embryonic stage and with the use of a DNA probe, one can know the sex of the embryo. Another way is the sorting of semen, one sperm at a time, into males and females, using staining procedure and detecting by laser beam with the help of standard flow cytometry equipment. Thus, sperms with an X or Y chromosome could be used to produce male or female embryos /animals.

6. Cloning

The first successful cloning in domesticated animals was achieved, using early embryonic source material, nuclear transplantation,


embryonic cultured cell line and somatic cells of adult animals (“Dolly” sheep. Eight cloned calves were produced from cumulus and oviduct epithelial cells of an adult cow. Cloning using somatic cells offers opportunities to select and multiply animals of specific merits. Cloning holds the promise of bypassing conventional breeding procedures to allow creation of thousands of precise duplicates of genetically engineered animals or other animals in a single generation. In remote areas, where sampling and storage of adequate samples of semen and embryos is not practical, one could use clonal samples from diverse

animals for conservation of the available genetic diversity of such threatened genetic resources.

Many animal species are in danger of extinction. In India, one horned rhinoceros, swamp deer, Manipur bro antler deer, hispid hare, wild buffalo,

Assam root turtle, pigmy hog, and Bengal florican, are classified as highly threatened animals in their present habitats. Cloning technique might be applied to increase the population sizes of endogenous species or even restore them following extinction. A broad spectrum of biodiversity can be collected and cryopreserved at modest cost. For reproduction of endangered species some zoo center have created a collection of frozen fibroblast cell cultures and tissue samples collected from various rare and threatened animal species. China has announced the initiation of a programme to increase the giant panda populations, using nuclear transfer techniques involving even the possible use of bear as egg donors and surrogate mothers.


2. FEED ENHANCEMENT

Biotechnological contributions to livestock nutrition include single cell protein production, improving feed crops through genetic modification, probiotic and biotic feed additives, and the use of enzymes for enhancing the nutritive value and quality of feeds. These technologies assist in the effective utilization of low nutrient content feedstuff into animal products.

3. ISSUES

Of these (above) innovations and related issues, the most important and contentious ones are

a. the regulation of the testing and utilization of transgenic animals in agricultural environments,

b. immunology and

c. the trans-species transmission of diseases. As compared to transgenic plants, there has been limited application of transgenics in animal production environment. Because of the “contained” nature of most present uses of transgenic animalsBiotechnology and Biodiversity, with the lesser risk of unwanted escapes into the environment, there has not been much concern in public mind on this issue.

There are differences based on religious believes related to the extent to which scientists may interfere with animals per se and animal genomes. There has been little concern in public about the applications of transgenic animals for pharmaceutical purposes and in bio-medical research. However, the world debate has centered around several issues viz., public views on


a humankind and its relationship with nature, especially co-modification of nature by humans and antagonism between agrarian societies vs. industrialization;

b. adverse social and economical impacts, especially benefits to corporations vs. small farmers;

c. biosafety viz., harmful side effects (in recipient animals and humans) and environmental risks (especially unpredictable expressions in an alien environment);

d. profit motives vs. altruism of human behaviour;

e. loss of animal genetic diversity and integrity of species; and

f. altering of natural course of animal evolution. Raising calves in the dark and feeding them with diet, for developing high quality veal, and battery rearing of broilers have been considered as unethical.

Activity :How a lack of biodiversity almost caused a nation’s extinction Many of the crops we grow for food are clones. Plants reproduce very easily by various forms of cloning, which is a great advantage to us. We can find a plant with


excellent characteristics for a particular use and we can make countless clones that will have identical excellent characteristics rather than breed them with others and then compromise the excellence we want. Potatoes are excellent examples of clones. Potato crops are planted from seed potatoes and not seeds as many of our other vegetables. Potatoes are modified stems and not plant sexual organs such as beans or pumpkins. So a potato will have the same genetic make up as the plant that feeds it above the ground. If a potato plant produces ten seed potatoes that are harvested and planted in fields for potato propagation, those ten potatoes will be clones of the parent plant, of each other and will also grow into new potato plants that will produce more of the same clones. The opportunity for biodiversity within the potato in this crop management system is very limited.

In 1845 a disease caused all the potato crops in Ireland to fail. They succumbed to the fungus called Phytophthora infestans which causes potato blight. The Irish population was decimated by starvation, disease (as a result of malnutrition) and emigration as those strong enough and with the financial means left their country to find a better life elsewhere.

1. What could have been done in the nineteenth century to prevent this devastation?


2. Cloning is a form of vegetative reproduction that occurs naturally. Man has over the centuries, since the agricultural revolution, emulated natural cloning for some crops. There are benefits to cloning as well as problems that could result from it. Using the Irish potato famine as the context, discuss the pros and cons of cloning in potatoes.

class-9 - edusys · 4 / class 9 eduheal foundation ... titis, rabies, aids, tb, polio; pulse polio...

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