what is biology? - mrs. macey's web pages -...
TRANSCRIPT
What is Biology? What is Science?
Science is a way of gaining ____________ and ____________ about our natural world.
Whenever we ask ____ or ____ something happens we are dealing with science.
What is Biology?
Biology is the study of __________________.
There are six major categories (Kingdoms) that living things have been divided into:
____________________
____________________
____________________
____________________
____________________
____________________
There are many branches or divisions of biology, each specializing in the study of a specific group of living
things.
Division Area of Specialty
What is a living thing?
In order for something to be considered alive it must show certain characteristics. Living things…
Living things will show all of these characteristics but there are some exceptions. For example,
____________________________.
Non-living things may show one or a few of these characteristics but not all.
Development of the Cell Theory Throughout history people have wondered what causes life and how life is maintained. It was not until
the invention of the microscope and improvements on the microscope that we were able to look at living
tissues and make detailed observations.
With these observations scientists came up with a formal cell theory that is used to explain
observations of living things.
1.
2.
3.
Types of Microscopes
____________________________ – single hand-held lens (earliest type of microscope)
____________________________ - contains 2 lenses, an eyepiece (ocular lens) and objective lenses.
___________________________ – uses an invisible beam of electrons to pass through an object.
Specimen must be dead and sliced very thin. Is capable of
magnifying up to 5 000 000 x.
_________________________ – reflects electrons from the surface of a specimen, allowing thicker
specimens to be viewed. Is capable of magnifying up to 300 000 x.
Historical Look at the Cell Aristotle - Classified all known organisms into two kingdoms: plant and animal. (334 BC)
Robert Hooke - Observed tree bark lining with a compound microscope; described the magnification as “empty room-like
compartments or cells” (1665)
Anton Van Leeuwenhoek - Reports living “beasties” as small as 0.002 mm observed with a simple single lens microscope
(1674)
Matthias Jacob Schleiden - “All plants are made of cells” (1838)
Theodor Shwann - “All animals are made of cells” (1839)
Carl Heinrich Braun - “The cell is the basic unit of life” (1845)
Rudolph Virchow - “Cells are the last link in a great chain [that forms] tissues, organs, systems and individuals… Where a cell
exists, there must have been a pre-existing cell…Throughout the whole series of living forms… there rules
an eternal law of continuous development” (1858)
Loiuse Pasteur - Demonstrates that living organisms cannot arise spontaneously from non-living matter (1860)
Classification of Organisms
Taxonomy -
The purpose of classification is to provide a clear and practical way to organize and
communicate information about organisms. Classification reduces _______, provides clues
about organisms’ ____________ and indicates lines of __________ (lineage).
A History of Classification
1. Aristotle
Greek philosopher (322 B.C.)
Divided organisms into 2 groups - ________ and ___________
Divided animals into 3 groups according to how they move - _____, _____, or _______
System was used into the ___________
2. Carolus Linnaeus
Classified plants and animals according to _______________________ - the more
features organisms have in common, the closer the relationship
His classification system is still used today
Designed a system in which each organism is given a ___________________ (latin)
He called this ________________________
1. “Genus” is always capitalized 2. “species” remains uncapitalized
The scientific way of writing binomial nomenclature would be in italics or underlined.
Examples:
Salmo salar Canis familiaris
Felis domesticus Canis lupus
Levels of Classification
Rank -
There are __ ranks to distinguish between different degrees of similarity, organisms are
classified according to ___ ________ within ____ _______. Each kingdom is subdivided into
progressively smaller groups. The named group for each organism is referred to as its ______.
As you proceed down the ranks, the numbers of members of each taxon becomes ________.
Rank Human Taxa ________ Taxa
The most widely used definition of a species is the __________ species concept. This idea
focuses on organisms that _________ freely in nature and produce _____, _______ offspring.
There are also the _____________ species concept (similarities in appearance) and the
_________________ species concept (evolutionary relationships).
3. Charles Darwin
Ushered in a new era of taxonomy with the publication, __________________ (1859)
Identified ________________ as a driving force behind ____________
Focus on groups that had _____________ from a common _____________
Attempts were made to find, “____________” between higher taxa, such as the fossil
Archaeopteryx between _________ and _________
4. Modern Taxonomy
Advances in ________________ have had a huge impact on the field of taxonomy
Biologists can now ______ and __________ the DNA (deoxyribonucleic acid) of many
different organisms and compare these DNA sequences to estimate relationships and
construct classification systems
Dichotomous Keys
A dichotomous key is a tools used to aid in the identification of organisms. In this
type of key, 2 questions are asked about the organism. Based on your response you
are directed to another question in the key.
Example:
_________
Determining Relatedness in Species One goal of taxonomy is to determine the _________________ of groups of organisms. To do this, scientists compare species
living _______ with species that existed in the _______. To study evolutionary relationships, scientists can use several
different forms of evidence:
1. Evidence from Anatomy
By studying the anatomy of living organisms or _____ remains, scientists are
able to determine the evolutionary history of different organisms. Biological
features that have a __________ ___________________ are said to be
__________. For example: the bones in a human arm, a cat’s leg, a bat's
wing and a whale's flipper.
Homologous structures differ from ________ structure; these are ones that
perform the _____ or ____________ by a similar mechanism but ________
___________. For example, the __________________________.
2. Evidence from Development
Scientists compare the early stages of development of an
organism to reveal relationships that are not always
_________ from comparison of _________ organisms alone.
3. Evidence from biochemistry
Scientists are now able to compare the _________ from which
organisms are made. Comparison of macromolecules like
__________ among organisms can indicate genetic similarities
and differences.
4. Evidence from DNA
The study of DNA can determine the _________________ in
common for different organisms. The DNA from humans and
chimpanzees are
____ identical.
DNA analysis can also determine how long ago two species began to diverge from a
common ____________. Divergence can be predicted by studying ___________
DNA (which differs from chromosomal DNA) as it is passed ______ from a
mother to her offspring and ______ at a predictable rate.
Phylogeny
When scientists classify species into various taxa, they are presenting a
hypothesis about the ________________, or _____________ of the organisms.
This information is often organized in a phylogenetic tree.
The base of the tree represents the ____________________, the upper
branches represent the _____________________ species and forks are where a
species ____ into two new species. New features evolved from a primitive
ancestor are called _________________________.
SBI 3UI
Prokaryotes and Eukaryotes
Prokaryotes
Eukaryotes
Kingdoms
Arrangement of DNA
Cell Division
Reproduction
Cell Structures
Size
Oxygen Requirements
Examples
Kingdom Archaea
The Kingdom Archaea contains one of the oldest groups of organisms on Earth. These
micro-organisms are all single celled (_____________) _____________ and tend to
live in very __________ environments (_____________). Some environments where
they thrive are:
Extremely cold or hot water and land masses(-4oC, 95oC)
Highly Acidic and/or basic waters (ph 2, ph 12)
Extremely salty waters (25%)
Archaea have evolved diverse ways to obtain their energy. Some are ____________
and obtain their energy from ______________________ (______________), while
others are ___________ and obtain their energy from ________________________
(_________________). Others use _________ (_____________) as their energy
source.
Although members of Kingdom Archaea and Bacterial look similar in appearance to each
other, _______________ and _______________ they are more different than plants
and animals. The ___________ (______) of the two kingdoms differ, as well as the
composition of their ________. In addition, the _________________ of organisms
within Kingdom Archaea contain unusual _________ that allow them to survive in
extreme environments that would normally __________ most cells.
Archaea’s ability to flourish in such extreme conditions is ___________ and not
completely understood. But the fact that these micro-organisms can tolerate such
environments have allowed scientists to use some of their components (____________)
when conducting experiments that require harsh processing i.e. PCR – polymerase chain
reaction
Kingdom Archaea can be divided into two major phyla :
1. __________________– which contains three main groups of archaea:
a) Methanogens (________________________) Live in _________________ environments and produce ______ as a waste product
Utilize inorganic molecules such as ________________________ or __________
____________ as a source of energy
Found below the surfaces of ___________, and __________, as well as _______
________________
Example: Methanococcus jannischii. This organism was isolated from a "white smoker" hydrothermal
vent some 2600m deep on the bottom of the Pacific Ocean...at a place called the East Pacific Rise.
b) Halophiles (____________________)
Live in extremely ____________ environments – concentrations may reach up to
_________ (seawater is 3.5% salt)
Found in the ___________, as well as other hypersaline water bodies including the interior
lakes of San Salvador Island in the Bahamas Example: Halobacterium salinarium carries out aerobic respiration but in water up to 5M (25%!) NaCl
(salt). It can be found in the Great Salt Lake in Utah and the Red Sea in Asia Minor.
c) Thermophiles (________________)
Live in extremely ____________________________
Can be found in piles of _____________ or in rocks deep below Earth’s surface
2. ________________________ – most of the organisms in this phylum are:
a) Thermoacidophiles (___________________________) Live in very _______________ water environments (corrosive conditions)
Grow best at temperatures above _________
Some use _______________ (________________) while others use ________ from hot
sulfur springs as their ____________ source
Found in _______________________________, and ____________________
While many archaea live in harsh environments, they have since been found in a broad range of
habitats, such as ____________________, and _______________. Archaea are
particularly numerous in the oceans, and the archaea in _____________ may be one of the
most abundant groups of organisms on the planet. Archaea are now recognized as a major part
of life of Earth and may play an important role in both the _______________ and
_____________. No clear examples of archaea __________ are known.
Kingdom Bacteria
All are __________ and the majority live as ________ (___________) but some occur in
________. They reproduce mainly _________ by ___________ but can have a _____
reproductive stage (__________). Most bacteria are __________, but some bacteria can
perform _________________ (_________________)
Biological Importance of Bacteria
Advantages
1)
Used in the production of cheese, vinegar, yogurt etc…
2)
Used as natural pesticides or added to soils to enrich nitrogen content (nitrogen fixation)
3)
Recycle organic material from dead organisms. Some bacteria are found in our intestines and
aid in the digestion process.
4)
Scientists have used bacteria to study cell metabolism and molecular biology.
Engineered bacteria are used to produce useful substances like: insulin, antibiotics,
hormones and anti-cancer drugs.
5)
Some bacteria naturally produce substances, which inhibit the growth of harmful organisms
(examples: streptomycin, erythromycin)
6)
The process of using bacteria to destroy, transform or immobilized environmental
contaminants.
For example, the bacterium Pseudomonas is used in the treatment of wastewater and
sewage; a toxic wood preservative can be removed from soil by a bacterium from the genus
Flavobacterium.
A relationship between two organisms (such as a bacteria and a human or plant or animal) is
called a ___________________. In cases in which both partners benefit from the
interaction it is referred to as _________________.
Disadvantages
1)
The action of bacterial decomposers can cause food to spoil and become harmful to eat.
Example: Clostridium botulinum (Botulism)
2)
Many bacteria are __________. These bacteria can also be termed _______, meaning that
one organism (the parasite) benefits at the expense of another organism (the host), which is
often harmed but usually not killed.
These pathogenic (disease causing) micro-organisms typically produce deadly substances
called ______. A toxin is a poison produced in the body of a living organism. It is not harmful
to the organism itself but only to other organisms.
There are two types of toxins that bacteria produce, endotoxins and exotoxins.
Endotoxins Exotoxins
Just one gram of the exotoxin that causes botulism could kill a million people!!!
Classification of Bacteria
Bacteria can be classified using many different criteria. Some of these include:
1) Shape (three types):
These shapes can be arranged in patterns or groupings:
2) Metabolic Needs
Classification based on:
Whether they are heterotrophs or autotrophs
Do they need oxygen? (aerobic or anaerobic)
Special food sources – carbon, nitrogen etc…
Examples:
Term Description
Needs oxygen
Die when exposed to oxygen
Can grow with or without oxygen
Use light as an energy source
Use chemical compounds as an energy
source
Feed on dead organisms or organic waste
Grow in temperatures above 50oC
Grow best in temperatures below 15oC
The Shapes of Bacteria
Thousands of different types of bacteria are known and have been observed. Scientists can tell these organisms
apart by the shape of the bacteria or by the way they join together. Write the meaning of the following terms.
1. bacillus ___________________________ 4. diplo _________________________
2. coccus ___________________________ 5. strepto _______________________
3. spirillum __________________________ 6. staphylo ______________________
Use the terms you defined above to name the bacteria in each diagram below. Write the name on the line below
each diagram. Note: Some names will combine two of the terms. For instance, a chain (strepto) of round
(coccus) bacteria is called a streptococcus.
__________________ ________________ __________________
__________________ ________________ __________________
__________________ ________________ ___________________
3) Colony Morphology
Describes the appearance of a colony in a Petri dish. Such as:
4) Reaction with Gram Stain
Gram __ retain crystal violet stain (_______) - contain a ________ layer in their cell wall
Gram __ do not retain crystal violet stain (______) – contain a _____ layer in their cell wall
5) Presence/Absence of:
Flagellum -
Capsule -
6) Spore Formation
Diagram of a Bacterium
Reproduction in Bacteria
The majority of time, prokaryotes reproduce _________ by a process known as
______________. Sexual reproduction is not very common in prokaryotes, but does occur in
some, such as Escherichia coli, by a process known as ___________.
Asexual Reproduction (Binary Fission)
Asexual reproduction is the formation of a new individual from a ____ organism. It results in a
genetically ___________ offspring. In favourable conditions, a bacterium can grow and divide
through binary fission in as little as ___ minutes.
Binary fission is prokaryotes can be broken down into stages:
1. DNA replicate (____________
________), resulting in identical
copies of genetic material
2. The two strands of DNA will then
___________
3. A new ____________ and _____
______ will develop through the
midsection of the prokaryote
4. The cells will eventually become two
_________________, which may
separate or remain attached
Sexual Reproduction (Conjugation)
Sexual reproduction is a process involving ___ organisms and results in offspring that are
genetically ____________ from both parents.
Conjugation in prokaryotes can be broken down into stages:
1. Two bacteria join together by forming a specialized structure called a _______.
2. Genetic information (_____________) is ________ through the pilus, resulting in an
altered set of characteristics.
3. Following the transfer, the two bacteria separate and can then undergo binary fission.
The result of the uptake of a new piece of DNA by conjugation can have many effects including:
1)
2)
In both cases, if the piece of DNA is inserted into the chromosome, then the process is called
______________________.
This produces a permanent change in the DNA of the cell, which is ___________ to the
________________ of that cell.
During unfavourable conditions, some prokaryotes survive by forming dormant or resting cells,
called __________, which can withstand harsh environments such as ______ and ______.
When suitable conditions return, the prokaryote will re-emerge and begin _______________.
Bacterial Growth
Bacterial growth curves take on a particular pattern, which shows the rate at
which bacteria will reproduce when conditions are optimal. A typical growth curve
consists of 4 different phases:
Lag phase –
Exponential growth phase –
Stationary phase –
Death phase –
Bacterial Growth Curve
The maximum number of organisms a particular environment can support is
termed the _____________________
Growth rate is the time it takes for a population of bacteria to
__________ in number
Like all organisms, bacteria thrive under __________ conditions The primary reason that our planet isn’t buried under a thick layer of
bacteria can be attributed to the fact that conditions are rarely ______
for the bacteria to grow. Scientists who study bacteria try to create the
optimal environment in the lab: culture medium with the necessary
___________, _________, ___, and ________________, in which
bacteria grow predictably
Generation times for some common bacteria under optimal conditions of growth
Bacterium Medium Growth Rate
(minutes)
Escherichia coli Glucose-salts
Bacillus megaterium Sucrose-salts
Streptococcus lactis Milk
Streptococcus lactis Lactose broth
Staphylococcus aureus Heat infusion broth
Lactobacillus acidophilus Milk
Rhizobium japonicum Mannitol-salts-yeast
extract
Mycobacterium tuberculosis Synthetic
Treponema pallidum Rabbit testes
Viruses
A virus is an extremely _________ (____________) particle that carries out no
______________ and cannot _______ on its own. On this basis, viruses occupy a position
between ____ and ____________ matter.
A virus consists of genetic material (___ or ___) wrapped in a ___________ (____), but lack
all other cell structures.
All viruses are _____________, reproducing by infecting a specific cell and using the host’s
machinery to ________ itself. For this reason they are known as __________
_____________.
Temperate viruses are those that reproduce without _____ their host cell. Typically viruses
will reproduce in two ways: through the __________ and the ________ cycle.
Viral Reproduction
The Lytic Cycle (T4 Example)
Phage finds the right bacterium,
attaches to the cell with its tail
fibres to a _________________ site
and uses an _________ to bore a hole
through the cell wall.
Bacteriophage injects its _______
material into the bacterium.
The bacteriophage genome
makes many copies of itself by
using _________________ (ribosomes).
The bacteriophage components and
_____________ continue to be produced.
The components of the
bacteriophage are assembled.
Bacteriophage enzyme breaks down
the bacterial cell wall causes
the bacterium to split open (______)
The Lysogenic Cycle
In the lysogenic cycle, the phage's ___ recombines with the bacterial ___________. Once it
has inserted itself, it is known as a ________. The bacteria and the prophage can ______
normally. Sudden changes in the ____________ may activate the phage ______________
and cause a production of viral particles.
Classification of Viruses
Viruses cannot be classified in the same way as bacteria. Viruses are clustered according to:
i.
ii.
iii.
iv.
Viral shape is an important characteristic because it…
i.
ii.
iii.
iv.
Structure of a Virus
How Do Viruses Spread?
Viruses are usually spread by ______. Vectors are anything that assists the spread of an
______________.
Ex.
How Do Animals Spread Viruses?
Viruses are contained within the infected animal. During a ____, the virus located in the
____________ (______ or ________) can come into contact with another animal’s blood
causing _________________ of the virus infection.
How Do Humans Spread Viruses?
Viruses can be spread by contact of an infected individual’s
________________ with a non-infected individual’s secretions.
Ex.
How Do Viruses Spread by Water?
Many viruses replicated within the host are __________ and carried away with the _______.
Some viruses can survive ______________ and are released into _______ and ___________.
How do Viruses cause problems in humans?
Typically the symptoms displayed from a viral infection are NOT a result of cells being
___________, but rather the body’s own ________ and _______ to fight off the virus (ex.
__________)
Differences Between the Common Cold (Rhinovirus) and the Flu (Influenza)
Symptoms Cold Flu
Rare Characteristic, high
(100-102°F); lasts three to four days
Rare
Prominent
Slight
Usual; often severe
Quite mild
Can last up to two to three weeks
Never
Early and prominent
Common
Sometimes
Usual
Sometimes
Common
Sometimes
Mild to moderate;
hacking cough
Common; can become severe
Sinus congestion
or earache
Bronchitis, pneumonia;
can be life-threatening
None
Annual vaccination*; Symmetrel, Flumadine, or
Tamiflu (antiviral drugs)
Only
temporary
relief of symptoms
Symmetrel, Flumadine, Relenza,
or Tamiflu within 24-48 hours
after onset of symptoms
1-4 days 1-4 days
RNA RNA
Vaccination – the administration of an antigenic agent that stimulates the body to develop resistance to
a pathogen.
A vaccination against the small pox virus was the first created (1976) and administered on a global scale,
such that it is the only pathogen to be eradicated from the planet (1977).
Kingdom Protista
All Protists share the following features:
Most are ________; multicelluar forms do not form tissue
Cells are _______________
Cells reproduce ________, but some can reproduce with
_________________________________________
Always found in ________ environments (fresh water, salt water, animal fluids…)
The Kingdom Protista can be separated into three distinct groups based on their nutrition:
Plant-like Protists
Animal-like Protists (Protozoa)
Fungi-like Protists (Slime moulds and Water moulds)
Classifying protista can be difficult because the members of this Kingdom are grouped together
mainly because they do not fit into the other Kingdoms, rather than because they are similar or
closely related to one another.
Plant-like Protists
These organisms are __________ that contain ________, the pigment that begins the process
of ___________. During periods of darkness, some cells will engulf ________.
_______ are type of plantlike protist and are responsible for about ____ of the global supply of
______. These can range in size from single cells to giant seaweeds _____ in length. Algae are
classified into six phyla, based
partly on the type of
____________ and
___________ they contain.
Human waste and industrial
contaminants can ______ algal
populations. Excessive algae
(__________) can block sunlight
from penetrating the water
Algae can be consumed as _____,
used as ____________ or in the
production of _____________.
Animal-like Protists (Protozoa)
Protazoa are heterotrophs that move around to obtain food, using _____, ________ or
__________. Some will ____ their food; others will _____ nutrients directly through their
cell ________________.
Some protozoa are unable to move; they are exclusively _______ and form reproductive cells
called _________.
Protozoa are classified mainly by their mode of _________________.
Fungi-like Protists
These organisms are referred to as ____________ (2 groups) or ____________ (1 group).
They prefer ________________ places usually under fallen leaves or rotting logs. These
organisms are _________________.
Helpful and Harmful Protista
In addition to providing food and oxygen, protists also live in our ____________ to aid in the
digestion process.
Some of the world’s most serious diseases are caused by protists:
Plasmodium vivax (malaria)
Giardia intestinalis (found in untreated drinking water)
Trypanosoma (African sleeping sickness)
Life Cycle of the Plasmodium vivax
Most widespread human
parasite
Causes malaria in
humans
Can be treated with
drugs
Kingdom Fungi Fungi DO NOT ____________. Fungi are ___________ ( ___________) that feed by releasing
digesting _______ into their surroundings, then absorbing the nutrients into their cells; this is called
_____________ _______________.
Fungi are composed of ________ cells that may be ___________ (yeasts), but the majority are
___________ (moulds and mushrooms). Fungal cells have a ______________ composed of ________.
Fungi can reproduce ______ and _______ but will always produce _____. Spores are typically _____
(contain half the amount of genetic information) and in multicellular fungi are produced in ________. If
a spore germinates, it produces _____, which are a network of fine ________. Hyphae are the main
part of fungi and are found under the ground; a group of hyphae are referred to as a _____________.
Fungi can be harmful and cause ________ in humans (_____________), plants and animals. Fungi are
also very important to __________ because of their role as ___________. Fungi form many
____________ relationships:
a) Plant Roots (form myccorhizae)
The fungal hyphae help the plant absorb ___________ – increase the _______________
The plant shares its ________________ and ________________
b) Cyanobacteria or Green Algae (form lichens)
Fungal mycelia provide _______________ and ________________ and _________ to the
autotrophic partner
The autotrophic partner shares _______________
Fungi Reproduction
Fungi reproduce asexually. When a piece of hyphae ____________ it will grow into a new ______.
This is referred to as _________________.
Spores are the main means for reproduction employed by fungi. The spores that are produced by fungi
may be asexual (produced by _______) or sexual (produced by ________). Spores have a protective
outer coating that prevents them from __________. Fungi will produces spores in the ______, which
like seeds can spread by ____, ______ or on the ________________. If a spore finds a
__________________ it can grow into a new organism.
Classifying Fungi
1. Zygospore Fungi (Zygomycotes)
This group includes ___________. During sexual reproduction they form ____________ after the
mating of two opposite strains of _____ (mating strains + and -). Some of these fungi produce two
kinds of hyphae, __________ (horizontal) and ___________ (downward) that anchor and secrete
digestive enzymes.
During asexual reproduction _________________ project above the mycelium to release spores from
_________________.
2. Club Fungi (Basidiomycotes)
This group includes the ____________ that grow on lawns. These have short lived reproductive
structures called basidiocarps (fruiting bodies) that form ____________ on a structure called
________. The largest part of the club
fungus is a vast, sprawling network of
hyphae that spread _______________.
3. Sac Fungi (Ascomycotes)
This is the ________ group of fungi and
includes _____ and single-celled _____.
Sac fungi form small finger-like sacs
called ____ during sexual reproduction.
Spores are produced directly at the tip
of modified hyphae.
4. Imperfect Fungi (Deuteromycotes)
Do not appear to have a _________ phase. They develop asexually from spores called _________.
Many of these fungi produce __________ (penicillin and cyclosporin) or are used in the production of
________ (soy sauce and cheese).
Kingdom Plantae
Plants are ___________, __________ organisms. Plants are
________, meaning that they produce their own food through
the process of ___________________.
Plants have a life cycle in which they alternate between two
forms (called ______________________________):
i) Haploid form
Called a ____________________ (produces gametes)
ii) Diploid form
Called a ____________ (result of the union of two gametes)
Major Divisions
Non-Vascular Plants
(bryophytes)
e.g. mosses
Seedless Plants
(pteridophytes)
e.g. ferns
"Naked Seeds"
(gymnosperms)
e.g. conifers
Monocots
e.g. corn
Dicots
e.g. beans
"Enclosed Seeds"
(angiosperms)
e.g. trees, shrubs, flowers
Plants with Seeds
(spermatophytes)
Vascular Plants
(tracheophytes)
Plant Kingdom
Vascular and Non-vascular Plants
Most plants consist of ______________________________:
- Roots penetrate the soil to ________ the plant and to reach sources of ______
- Leaves provide a greater _____________ to carry out ___________________
- Stems supply rigid tissues that _______ and __________ the ___________
In order for roots, leaves and stems to grow they need a regular supply of ______, and
_____________
These tasks are carried out by vascular tissue - vascular tissue are made up of cells that
conduct solutions throughout the plant (similar to a circulatory system)
There are two main types of vascular tissue:
Xylem -
Phloem -
Evolution of vascular tissue has allowed plants to
increase in ________
Non-vascular Plants (Mosses and their Relatives)
There are three divisions of Mosses:
1. Mosses (__________________)
- Lack vascular tissue and do not have well-developed roots
- Thrive in diverse habitats such as bogs, tundra, exposed rocks and deep shade
2. Liverworts (_____________________)
- Grow flat and close to the ground
- Rarely more than 30 cells thick
3. Hornworts (______________________)
- Gametophytes are broad flat and usually less than 2 cm in diameter
- Have a blue-green colour
Seedless Vascular Plants (Ferns and their Relatives)
Developed vascular tissue that
allowed them to grow tall
Sporophyte generation is the
dominant stage
Gametophyte generation are
tiny, short-lived and depended
on moisture to carry out
sexual reproduction
(prothallus)
Vascular Plants (disperse by
seeds)
Seeds allow a plant to
reproduce sexually without
needing water
Seeds also provide protection
against harsh environmental
conditions
There are two groups of seeds:
1. Gymnosperms "naked seeds"
These are ___________ plants
with most possessing ________.
There are both male and female cones.
Generalized life cycle of a gymnosperm:
In male cones, microspore mother cells undergo meiosis to produce haploid pollen grains, the
male gametophytes.
Female cones have ovules in which a megaspore mother cell undergoes meiosis to produces
only one megaspore, or female gametophyte.
Pollen gets trapped on sticky sap secreted by the female cone.
After fertilization, the diploid zygote develops into an embryo, which remains in the ripened
ovule, now called a seed.
Mature "naked" seeds fall out of the female cones.
It may be several years before the seedling grows into a mature plant to produce its own
cones.
2. Angiosperms
_________ plants that protect their seeds within a _____. Monocots have one _______
(seed leaf) and dicots have two cotyledons.
Generalized life cycle of an angiosperm:
Within the anther chambers, microspore mother cells undergo meiosis to produce haploid
pollen grains, or male gametophyte.
Within the ovule, a megaspore mother cell undergoes meiosis to produce only one megaspore,
or female gametophyte.
Pollination is aided by wind, insects, birds, and bats.
Pollen gets trapped by the sticky substance on the stigma.
Self-pollination involves one plant only; cross-pollination involves two separate plants.
After fertilization, the diploid zygote grows into an embryo, which remains in the ripened
ovule, now called a seed.
As the seeds develop, the ovary and other parts develop into the fruit enclosing the seeds.
The Life Cycle of a Flowering Plant
Kingdom Animalia
Animals are ________, _________ __________ that reproduce ____________ and are
usually capable of ___________ at some stage of their lives.
This complex kingdom is divided into two broad groups:
1. Invertebrates (majority of animals)
Do not have a ___________. Examples: leeches, clams, insects
2. Vertebrates
Have a ________________ (a rod shape structure that extends the length of the body;
often replace by the spine)
Examples: fish, amphibians, birds, reptiles and mammals
The following are major characteristics used to classify animals:
1. Body organization
Organized of tissues into organs, organ systems etc…
2. Body Layers
Three different types:
i) _________ (outer e.g. skin, nervous system)
ii) _________ (inner e.g. lining of body cavity)
iii) _________ (middle layer e.g. circulatory system)
3. Body Symmetry
i) ____________
ii) ____________
iii) ____________
4. Digestive tract or gut
i) _____ opening – Example: Hydra
ii) _____ openings - Example: Earthworm
5. Coelom ________________________
Allows for the development of
more ____________________
A Quick look at Animals
The First Animals
Sponges (Porifera) Live permanently attached to one surface
Cells are organized in a simple fashion
Single opening
No tissue no organs and only two layers of cells
Jellyfish, Corals and Anemones (Cnidaria) Two cell layers and a single opening
Simple nervous system and muscle tissue
Allows then to swim and capture prey
Use digestive enzymes for external digestion
No special excretory or respiratory systems
Flatworms (Platyhelminthes) Parasitic tapeworms and flukes as well as free living
planarians
Digestive system is a closed pouch with one opening
Lack circulatory system but have a simple excretory
system
Simple nervous system and a brain like concentration of
nerve cells at the head
No coelom
Segmented Worms (Annelida) Earthworms and leeches
Body is divided into ringed segments that
contain similar sets of organs for excretion,
circulation and nerve control
Other specialized organ systems including
digestive, and reproductive
Open digestive system; two openings
Contain a coelom
Squid, Clams, Snails (Mollusca) Soft Body, hard shell (for many of the organisms)
Three cell layers
Open digestive system; two openings
Contain a coelom
3 different classes include the Bivalves, Gastropods and Cephalopods
Second most diverse group but all have a similar body plan including a mantle which
surrounds internal organs and secretes calcium carbonate for the shell as well as a
muscular foot for movement
Contain specialized organ systems including digestive, circulatory, respiratory, excretory,
reproductive and nervous
Starfish (Echinodermata) All are marine
Include starfish, sea urchins, sea cucumbers and sand dollars
Adults are radially symmetrical, larvae are bilateral
Contain a coelom
Open digestive system; two openings
Contain specialized organ systems including water vascular, digestive, respiratory,
circulatory, nervous, reproductive etc..
Joint-Legged Animals (Arthropoda) Arthropods resemble annelids in basic structure
Annelids are very similar to larval stages of insects
Open digestive system; two openings
Contain a coelom
As arthropods evolved they developed several distinct differences from annelids. Such as:
o Fewer body segments
o Hard external cuticle which acts as an exoskeleton
o Legs divided into moveable segments connected by joints
o Have separate muscles organized into groups related to specific movements of
body parts
o Strongly developed jaws
o Better developed nervous systems and sense organs
o Other specialized organ systems including digestive, respiratory, circulatory and
reproductive
Chordates (Chordata) At some stage in their life history all chordates have: A dorsal nerve cord from which other nerves branch A notochord, or rod of cartilage, which runs along the dorsal length of the body
A notochord occurs only in the embryo
A backbone of cartilage or bone replaces the notochord
Gill slits in the pharynx, or throat (in terrestrial vertebrates the gill slits only appear in the
embryo)
Contain a coelom
Open digestive system; two openings
Contain specialized organ systems including digestive, respiratory, circulatory, nervous,
reproductive etc..