genetics- review...monohybrid- cross involving one trait. ex- tt x tt dihybrid- cross involving two...

Stahl EOC Review Part 2

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* Pictures were taken from a variety of websites by other people.

Genetics-

The father of genetics is Gregor Mendel and his pea plants!

Mendel’s Law of Heredity:

a. Law of Dominance- the dominant allele will prevent the recessive allele from being

expressed.

b. Law of Segregation- gene pairs separate when gametes (sex cells) are formed. Each

gamete has only one allele of each gene pair.

c. Law of Independent Assortment- different pairs of genes separate independently of each

other when gametes are formed.

Homologous Chromosomes= two chromosomes, one from mom and one from dad, that have

the same length and general appearance.

Trait- characteristic an individual receives from its parents.

Gene- carries instructions responsible for gene expression of traits; one comes from each parent

in the form of alleles.

Homozygous- two alleles of a pair are identical. (BB or bb).

Heterozygous- two alleles of a pair are different. (Bb)

Dominant- the expressed allele. Always the capitalized allele.

Recessive- allele is expressed only when two copies are present (hh). Always lowercase.

Genotype- genetic make-up (always the alleles / letters).

Phenotype- physical make-up (description like freckles).

Monohybrid- cross involving one trait. Ex- Tt X TT

Dihybrid- Cross involving two traits. Ex- TtWW X TTww

Punnett Square- shows the probable results of genetic crosses.

Pedigree- maps genetic traits between generations.

Mutations-

Change in genetic code


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Transmitted to offspring if occurs in sex cells

Gene mutation- change in a single gene

Chromosome mutation- change in many genes

Can be spontaneous or caused by environmental mutagens

Sources of Variation:

a. Crossing over- genes from chromosomes are exchanged with genes from another

chromosome. Prophase of Meiosis.

b. Nondisjunction- during meiosis homologous chromosomes do not separate. Results in

half of the sex cells having an extra chromosome and the other half having one less. If

fertilization occurs with an abnormal sex cell, zygote formed will have either one extra

(trisomy) which would be three chromosomes, or one less (monosomy). Example of

trisomy = Down syndrome, monosomy = sickle cell anemia.

Monohybrid- cross involves one trait.

Example- RR X Rr R R

How do I set up a Punnett Square?

Step 1- The first set of alleles to the left of the “X” goes along the top of the square.

Step 2- The second set of alleles to the right of the “X” goes along the side of the square.

Remember only one letter per box!

Step 3- Start crossing them.

R

r

RR RR

Rr Rr

Always put the capital

letter first!

Genotype= 2 RR, 2 Rr

Phenotype- all round


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Dihybrid Cross

Ex) A tall green pea plant (TTGG) is crossed with a short white pea plant (ttgg). Use the FOIL method.

TT or Tt = tall tt = short GG or Gg = green gg = white

TG TG TG TG

tg

tg

tg

tg

16 Tall/Green : 0 Tall/White : 0 Short/Green : 0 Short/ White

Incomplete Dominance- intermediate / blended phenotype.

Example- snap dragons-> Red X White = pink flowers.

Codominance-both parental phenotypes show up in offspring.

Example- chickens-> Black X White-> black and white feathered chickens.

Multiple Alleles- trait with 3+ alleles.

Type of codominance

Ex- blood types- A, B, O (Ia, Ib, and i).

Both Ia and Ib result from a protein called an antigen, on the surface of red

blood cells.

Allele i is recessive and does not result in an antigen.

TtGg TtGg TtGg TtGg

TtGg TtGg TtGg TtGg

TtGg TtGg TtGg TtGg

TtGg TtGg TtGg TtGg


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Polygenic inheritance-traits that are produced by two or more genes.

Ex.- human skin color, eye color

Albinism- there is a gene that blocks the color-> albino.

Aneuploidy- condition caused by having abnormal chromosome number. Ex- Down syndrome,

also known as trisomy 21.

Sex Linked-

Genes carried on sex chromosomes, specifically the X chromosomes.

Ex- Hemophilia and colorblindness.

Always use the X chromosome, therefore the actual gene that codes for hemophilia will

be represented by a subscript H (normal) or h (carrier)

Ex- A normal man marries a woman who is a carrier for hemophilia, predict their

offspring.

X Ⱨ Y

*** because the male has the normal blood clotting allele he will have a H by his X

chromosome because he is normal and they are only on X chromosomes. The female

is normal but she is a carrier that mean she will have one allele= h on one of her X

chromosomes. ****

XH XH Normal daughter

XH Y Normal son

XH Xh Daughter is normal but is a carrier.

Xh Y This son is a hemophiliac

XⱧ

Xh

100 % of the females are

normal.

50% of the males are normal

50% of the males are

hemophiliacs.


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Biotechnology:

DNA Extraction- the opening of cells to separate / isolate DNA from other cell parts.

DNA fingerprinting

Human Genome Project

Transferring DNA from one organism to another.

Sequencing DNA

Separating DNA through gel electrophoresis.

Pedigree Charts

* Chart of genetic history of a family over several generations.

* = female = male * Not filled in = Normal

* Married Couple=

Offspring

* If the individual is infected with a disease etc. then the square or circle will be filled in.

* If the individual is a carrier then the square or circle will be half filled.

* Autosomal pedigree- there is about a 50 / 50 split between males and females.

* Sex linked- if most males are affected.

* Dominant- one parent must have it.

* Recessive- neither parent has it.


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Evolution

Father of evolution = Charles Darwin

Evolution= species and populations change over time.

Natural selection = “ survival of the fittest”

Organisms that are best suited to the environment survive and pass genetic traits on to

offspring

Adaptation- organisms with the most suited traits will survive.

Conditions required for Natural Selection:

More organisms are born than can survive= Overproduction of offspring

Organisms vary in their characteristics, even within a species= Inherited variation

Differences in reproduction and survival are due to variation among organisms.

If all four of these conditions occur, which they commonly do in both natural and human-influenced ecological systems, then natural selection will occur. If any of these is not true, then natural selection cannot occur.

Scientists: there were many naturalists before Darwin that discovered evolution- Darwin

just built upon them.

Carolus Linnaeus- Organized plants, animals, and minerals based upon their

similarities into a detailed classification system. Still used today:

o Kingdom

o Phylum

o Class

o Order

o Family

o Genus

o Species- the most distinctive group because he found that they were a group

of organisms so similar to one another that they can reproduce and have

fertile offspring.

o Example of genus, species= Homo sapiens (Homo= genus) and (sapiens=

species).

* Georges Buffon- proposed that species shared ancestors instead of arising

separately.

Good way to remember taxonomy

and the order is the phrase” King

Phillip Came Over From Greater

Spain”


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* Erasmus Darwin- Charles Darwin’s grandfather, Proposed that all living things were

descended from a common ancestor and evolved through mechanisms like

competition.

* Jean Batiste Lamarck- changed in the environment caused an organisms behavior

to change, leading to greater use and disuse of structures or organs.

Evidence of Evolution:

Fossils- can be found in rocks, ice, amber, etc; they are arranged in order of their age

(usually strata = layers in rocks) where the older fossils will be found the deeper you

go. They are then aged and placed in the geological time scale. Allows us to compare

anatomical characteristics that are shared by different ancestors.

DNA- gene or protein sequences from organisms are arranged; species that are

related based on fossil evidence are more similar than species thought to be distant

relatives one the DNA is analyzed.

Embryology- embryos of different vertebrates look alike in earlier stages. You cannot

tell the difference between the larvae of a fish and a crab- they look the same.

Biogeography- Organisms on different islands looked similar; therefore they had

migrated and went through anatomical changes based on the climate, food, etc.

o Example= Galapagos Finches.

Comparative Anatomy

o Homologous Structures- features that are similar in structure but appear in

different organisms and have different functions. Ex- the hand of a human,

the wing of a bat, and the flipper of a dolphin -> several similar bones, but

different functions. Different in detail but similar in structure.


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o Analogous Chromosomes- structures that perform the same function, but are not

similar in origin. Ex- wings on a bat and wings on a bird.

o Vestigial Structures- structures that have lost their function. Ex- appendix and hip

bones in whales.

Microevolution Macroevolution

Evolution that occurs within the

species level; results from genetic

variation and natural selection

within a population.

Ex- antibiotic resistance

Ex- pesticide resistance

Evolution that occurs between

different species; focuses on how

groups of organisms change.

Convergent evolution- two species

evolve similarly, but are in different

areas.

Divergent evolution- a group of

species evolve differently.

Adaptive Radiation- a group of

species adapt separately to

environments’. Ex- Darwin’s

finches

Speciation- formation of a new

species.

Geographic isolation- physical

barrier that divides a population,

results in individuals that cannot

mate, leads to a new species.

Reproductive isolation- genetic

mutation or behavioral change that

prevents mating.


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Genetic variation within populations:

Increases the chance that some individuals will survive.

The greater variation in phenotypes the more likely it is that some individuals can

survive in a changing environment.

Example- short round penguins might be able to stay warm more easily, but if there is

a shortage on food, taller penguins might be able to dive better and catch more fish.

Stored in an organisms gene pool = combined alleles of all of the individuals in a

population- differences are caused from organisms mating and having offspring.

Comes from two main sources: Mutations and recombination

o Mutations- random change in the DNA of a gene and this can cause a new

allele to form. Ex- frogs going from green to brown for a survival advantage.

o Recombination- alleles get shuffled around resulting in different genetic

combinations.

Classification

Taxonomy- the process of biology that studies the grouping and naming of organisms.

Aristotle proposed the two groups, plants and animals-> based on whether or not the

organisms had blood or no blood.

Early 1700’s= Carl Linnaeus and his classification was based on physical characteristics.

o 2 kingdoms

o Developed genus and species (Homo sapiens)-> Homo= genus, sapiens= species

o Naming system is called binomial nomenclature- which means two names. The

genus is always capitalized and the species is always lowercase- both italicized.

written in italics

-1st word is Capitalized –Genus

-2nd word is lowercase —species

Levels of Classification:

Kingdom

Phylum

Class

Order

Family

Genus

Species

A way to remember the order is by

using the phrase

“King Phillip Came Over From

Greater Spain”


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Example: Humans

Kingdom- Animalia (because we are animals and multicellular)

Phylum- Chordata (characterized by a dorsal hollow nerve cord, notochord, pharyngeal

gill slits)

Class- Mammalia (We are mammals!!!! Give birth to live young, endothermic, and we

have mammary glands)

Order- Primates (nails, clavicle, orbits encircled with bone, enlarged cerebrum,

opposable digits- thumb, it can turn backwards).

Family- Homidae (bipedal- walk straight up on two feet, advanced tool use

Genus- Homo (Human like)

Species- sapiens (of relating to)

6 Kingdoms:

- Archaebacteria

- Eubacteria

-Protista

-Fungi

-Plantae

-Animalia


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Kingdom Characteristics

Monera

Archaebacteria

and Eubacteria

Protista Fungi Plantae Animalia

-Bacteria

-Prokaryote

-Unicellular

-Aerobic /

anaerobic

-Decomposers

-Heterotrophic

-Photosynthetic

-Chemosynthetic

-Pathogenic

-Medicinal

-Classified by

shape: coccus are

spherical,

bacillus are rod-

shaped , and

spirillum are

spiral

-Binary Fission

-Vaccines,

antibiotics

-Move by

Flagella and

Cilia

-Protists

-Eukaryote

-Unicellular

-Aerobic,

anaerobic

-Pathogenic /

parasitic

- Animal-like

(protozoa)

-Plant-like

(algae)

- Medicinal, food

source

- Mobile

- move through a

pseudofoot,

flagella, and

contractile

vacuoles

Ex- amoeba

- Eukaryote

- Multicellular

- Aerobic

- Decomposer

- Lack

Chlorophyll

- Pathogenic

-Saprophytic- eat

dead stuff /

parasitic

- Medicinal /

food source

- Heterotrophic

- Sexual /

asexual

- Alternation of

Generations

-Symbiotic

relationships

with algae

Ex- mushrooms

- Eukaryote

- Multicellular

- Aerobic

- Producer

- Photosynthesis

- Cell Wall

(cellulose)

- Vascular and

nonvascular

systems

- seeds or cones

(angiosperms or

gymnosperms)

- Poisonous

- Medicinal, food

source

- Alternation of

generations

- Roots, stems,

leaves

- Pollination

(fertilization)

- Germination

- Ex- Oak

- Eukaryote

- multicellular

- Aerobic

- Consumer

- Cellular

Respiration

- Invertebrates

- vertebrates

- Symmetry

Ex- Humans

Some Examples of Protists!

Disease Protist Vector

(carrier)

Symptoms Details

Amebic

dysentery

Ameba

histolytica

water diarrhea can get from tap

water in some places

Giardaisis

(beaver fever)

Giardia water diarrhea,

vomiting

don't drink water

from streams

African

Sleeping

Sickness

Trypanosoma Tse tse fly uncontrolled

sleepiness,

confusion

Only found in

isolated areas

lives in blood

Malaria

Plasmodium Anopheles

mosquito

fever, chills,

death

can be treated with

quinine

lives in blood

results in millions

deaths per year

Toxoplasmosis Toxoplasma cats fetal death or

brain damage

pregnant women

should avoid cat

litter


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Body Symmetry of Animalia:

1. Radial Symmetry-Animals (such as coral and jelly fish) have body parts organized about

a central axis and tend to be cylindrical in shape.

2. Bilateral Symmetry-(such as humans and fish) has only a single plane of symmetry that

produces mirror halves.

3. Asymmetrical- (sponges) have no general body plan or axis of symmetry that divides the

body into mirror-image halves

Some Phyla of Animals 1. Porifera – simplest animals: sponges 2. Cnidaria – have stinging cells: jellyfish, sea anemones, corals 3. Platyhelminthes – flatworms: planaria, flukes, tapeworms 4. Nematoda – roundworms: nematodes 5. Mollusca - soft bodies: snails, octopus 6. Annelida - segmented worms: earthworms, leeches 7. Echinodermata – spiny skinned, radially symmetrical: starfish, sea Cucumbers, sand dollars 8. Arthropods – exoskeleton: arachnids, crustaceans, centipedes, insects 9. Chordata - have nerve chords: vertebrates like fish, birds, and mammals

Ecology

ADAPTIVE RESPONSES:

Mimicry – structural adaptation that allows one species to resemble another species; may

provide protection from predators

Camouflage – structural adaptation that enables species to blend with their surroundings; allows

a species to avoid detection

Migration – instinctive seasonal movements of animals from place to place

Emigration – movement of individuals from a population; leaving the population

Immigration – movement of individuals into a population

Hibernation – state of reduced metabolism occurring in animals that sleep during parts of cold

winter months; an animal’s temperature drops, oxygen consumption decreases, and breathing

rate declines

Estivation – state of reduced metabolism that occurs in animals living in conditions of intense

heat


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Mating / Reproduction – production of offspring for the survival of the species; can be

seasonally scheduled

ANIMAL BEHAVIOR ADAPTATIONS:

Behavior – animal’s response to a stimulus

Innate behavior – instinct; influenced by genes

Ex: bird defending its nest

Learned behavior – changed by experience

Ex: training a pet to respond to a specific name

Social behavior – interactions between members of the same species

Ex: mating and caring for offspring

Territorial behavior – organisms defend an area to keep out other organisms (ex: animal

marking trees)

http://envirosci.net/111/trophic.htm

STRUCTURE OF AN ECOSYSTEM

Organism >>>>> Species >>>>> Population >>>>> Community >>>>> Ecosystem >>>>> Environment

Species – group of organisms that can interbreed Population – units of single species

Community – groups of interacting populations Ecosystem – groups of interacting communities

Habitat – place where an organism lives Niche – organism’s role within its habitat

http://envirosci.net/111/trophic.htm


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Food Chains: Series of steps representing who is eating who.

http://heightstechnology.edublogs.org/tag/foodchain/

Food Webs: Remember the arrows go in the direction in which the energy is flowing. This

shows a complex interaction of a variety of organisms.

http://www.dunkirkcsd.org/site/Default.aspx?PageID=1416

http://heightstechnology.edublogs.org/tag/foodchain/

http://www.dunkirkcsd.org/site/Default.aspx?PageID=1416


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ECOLOGICAL PYRAMID:

- Representation of energy transfer - Pyramid of Energy – each level represents energy available at that level, 90% decline - Pyramid of Biomass – each level represents amount level above needs to consume. 10% is

transferred to each level through heat and energy. - Pyramid of Numbers – each level represents number of organisms consumed by level above it

http://www.docstoc.com/docs/124467477/Ecological-Pyramids

http://www.docstoc.com/docs/124467477/Ecological-Pyramids


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Website unknown for the cycles.

CYCLES:

(Matter cannot be created nor destroyed, but can be converted/recycled to other forms)

Water Cycle – water is recycled through evaporation, condensation, precipitation, runoff, groundwater, aquifers, respiration, transpiration,

excretion, decomposition

Nitrogen Cycle – producers take in nitrogen compounds in soil and pass to consumers that consume the producers; decomposers (bacteria)

break down nitrogen compounds and release nitrogen gas to air or usable nitrogen so the soil.

Carbon Cycle – carbon is recycled through respiration, photosynthesis, fuel combustion, decomposition; carbon can be atmospheric or

dissolved, or can be found in organic compounds within the body.


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Reproduction= Fertilization- joining of a sperm and egg cell.

http://www.nationwidechildrens.org/body-system-reproductive-male

http://biologyataglance.wikispaces.com/Cells+and+life+processes

Testes – makes and stores sperm via meiosis. The testes are also

responsible for produces testosterone, the male hormone.

Sperm-male sex cells.

Scrotum- Pouch that encloses the testes.

Penis- organ where sperm leaves the body.

Urethra- where urine leaves.

Seminal Vesicle and Prostate Gland- release liquids into the vas

deferens when sperm is moving through it.

Testosterone is responsible for many of the "male" characteristics.

Epididymis – Where the sperm matures until it’s expelled or reabsorbed. Vas deferens - tube where sperm travels to the outside of the body. Bulbourethral gland / Cowper’s gland- adds fluid to the semen during ejaculation. Semen- a mixture of fluids that looks milky white.

* 2 important functions- nourishes, produces, and protects the

egg cells.

Vagina-birth canal, tube that leads from an opening outside the

body.

Uterus- strong, thick, muscular walls that holds and nourishes the

growing embryo.

Cervix- opening of the uterus at the top of the vagina, stretches

during birth.

Fallopian Tubes- connects the ovary to the uterus. The tubes

where the eggs travel down.

Ovaries- produce, store, and releases eggs.

Eggs-female reproductive cells.

Ovum- egg cell.

http://www.nationwidechildrens.org/body-system-reproductive-male

http://biologyataglance.wikispaces.com/Cells+and+life+processes


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http://www.healthac.org/female.html

* Estrogen is the hormone responsible for secondary sex characteristics.

* Progesterone is the hormone responsible for initiating menstruation.

* Testosterone is the hormone that initiates sperm production and male secondary sex

characteristics.

* Fertilization produces a new cell= zygote. 23 chromosomes from mom and 23 from dad= complete

set!

* An egg is usually a few days old before it implants in the uterus. At this point, it has already divided

several times and is called a blastula.

http://www.healthac.org/female.html


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* The period from fertilization to birth = gestation.

If the zygote has the incorrect number of chromosomes, it may never start growing. An extra

chromosome #21 will result in the baby having Down syndrome.

First Trimester Second Trimester Third Trimester Up to 3 months

Zygote divides several times to form a hollow ball called a blastocyst.

Embryo is implanted into the uterine wall – takes about 8-9 days.

Nourishment begins. Gastrula forms-> make

up the germ layers-> which develop into different structures.

Month 3 to 6

Fetus starts to move.

By the end it has fully developed eyes.

Lungs are starting to develop.

6 months- end

Brain develops rapidly.

Regular breathing Lungs aren’t fully

developed until the 36th week.


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Ectoderm-= outer layer-> forms skin, nerves, and sense organs.

Mesoderm=middle layer-> forms bones, muscles, and tissues.

Endoderm= inner layer-> digestive system and lungs.

All three layers developing in different ways is called differentiation.

After 8 weeks the major organs have begun to develop and then it is called a fetus

The Brain

http://www.snider.fwcs.k12.in.us/apbiology/homework/Unit%2015/chapter_48.

htm

http://www.snider.fwcs.k12.in.us/apbiology/homework/Unit%2015/chapter_48.htm

http://www.snider.fwcs.k12.in.us/apbiology/homework/Unit%2015/chapter_48.htm


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http://www.stroke-survivors.co.uk/About

http://www.cea1.com/anatomy-sistems/inner-brain-diagram/

http://www.stroke-survivors.co.uk/About

http://www.cea1.com/anatomy-sistems/inner-brain-diagram/


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Cerebellum- 2nd largest part of the brain. Controls basic movement, balance, and

posture.

Brain Stem- smallest part of the brain. Connects the cerebrum to the cerebellum and

the spinal cord. Crucial because it control involuntary responses- things that happen

automatically like breathing.

Cerebrum- the largest part of the brain.

Corpus Callosum- large bundle of nerve fibers that connect the left and right cerebral

hemispheres. Looks like a “C” on its side.

Medulla Oblongata- lowest section of the brainstem. Controls automatic functions including

heartbeat, breathing, etc.

Pituitary Gland- gland attached to the base of the brain (between the pons and the corpus

callosum) that secretes hormones.

Pons- connects the hemispheres of the cerebellum and connects the cerebrum with the

cerebellum.

Thalamus-regulator of sensory information and motor information. Also controls sleep and

awake states of consciousness.

Hypothalamus-produces hormones that control: body temperature, hunger, moods, release of

hormones from many glands, especially the pituitary gland, sex drive, sleep, and thirst.

Cerebral cortex- outer layer of the cerebrum. Interprets information from your sensory organs

and generates a response.

Frontal Lobe- personality, reasoning, and judgment. Voluntary movement and speech.

Parietal Lobe- Sensory cortex that interprets and coordinates information regarding the

sense of touch.

Occipital- Visual information is processed.

Temporal- Speech interpretation and hearing. Memory as well.

3 Major Parts

of the Brain


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https://www.nwpublichealth.org/archives/s2007/adolescent-brain

MAJOR SYSTEMS AND ORGANS

SYSTEM FUNCTION BASIC ORGANS, AND STRUCTURAL PARTS

Circulatory Transports nutrients, fluids, gases Heart, veins, arteries

Digestive Breaks down food into essential nutrients Mouth, esophagus, stomach, intestines

Endocrine Controls body functions through hormones Glands which secrete hormones

Excretory Removes cellular wastes from the blood Bladder, kidneys, urethra

Immune Protects the body against invading organisms White blood cells

Integumentary Protects the body by forming the body’s outer layer Skin, hair, nails

Muscular Moves the body with the help of the skeletal

system

Muscles

Skeletal Supports the body internally Bones, cartilage, ligaments, tendons

Nervous Coordinates sensory input with motor output Brain, spinal cord, sense organs

Reproductive Provides a means of producing offspring Testes (male), ovaries and uterus (female)

Respiratory Controls the exchange of gases Nose, pharynx, larynx, trachea, bronchi, lungs

https://www.nwpublichealth.org/archives/s2007/adolescent-brain


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DISEASE CAUSING MICROORGANISMS:

- Microorganisms are living organisms, usually unicellular bacteria, than can only be seen with a microscope.

- Benefits of microorganisms: help us to digest food, encourage normal development of the immune system, fight off bad

organisms

- Microbes (or pathogens) include viruses, bacteria, fungi, and parasites, which cause disease when our immune system can’t

fight them

- Microorganisms can be identified based on their size, shape, color, ability to form colonies, etc.

- Process of growing the organism is called a culture, and can be used to test sensitivity of organisms to various antibiotics which

will help a doctor determine which drug to use in treating an infection.

- An infectious disease in humans occurs when balance is disturbed by: exposure to an organism, normal microorganisms in the

body become pathogenic, or the human immune system does not act fast enough or strong enough.

- Most common areas on the body for microorganisms: skin, mouth, upper airway, intestine, genitals

EXAMPLES OF INFECTIOUS ORGANISMS:

- Bacteria – microscopic, single celled

Streptococcus pyogenes (strep throat)

Escherichia coli (urinary tract or intestinal infection)

- Viruses – cannot reproduce on its own (invades a host cell)

Varicella zoster (chicken pox)

Rhinovirus (common cold)

- Fungi – yeasts, molds, mushrooms

Candida albicans (yeast infection)

Tinea pedis (athlete’s foot)

- Parasites – organism such as a worm or single celled animal (protozoan) that survive by living inside another organism (host)


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Enterobius vermicularis

(pinworm)

Plasmodium falciparum

(malaria)

DEFENSES AGAINST INFECTION:

First Line of Immune Defense:

- Physical Barriers - skin, mucous membranes (linings of the mouth, nose, eyelids), airways,

stomach acid, pancreatic enzymes, bile, intestinal secretions, urinary secretions

Second Line of Immune Defense:

- Blood – increasing the number of certain types of white blood cells that engulf and destroy

invading microorganisms

- Inflammation – release or substances from damaged tissue isolates area to attack and kill

invaders and dispose of dead and damaged tissue, and to begin repair; blood supply

increases which brings more white blood cells to swollen area

- Fever – body temperature increases to enhance defense ability (controlled by hypothalamus

in brain); causes shivers, chills, body aches; normal body temperature is 98.6ºF, a fever is

considered higher then 100ºF.

Third Line of Immune Defense:

- Immune Response – immune system responds by producing substances that attack

invaders (ex: killer T cells, phagocytes) and the immune system produces antibodies that

attach to and immobilize the invader to kill it; antibodies will “remember” the infectious

organism so it will kill it upon next exposure; immune system is present all over the body and

tightly bound to blood and lymph systems; tissues and cells that provide antibodies include red

bone marrow, thymus, spleen, circulating lymphatic system, and white blood cells.

- There are two types of immunity:

- Natural Immunity – created by body’s natural physical barriers or in the form of antibodies

passed from mother to child

- Acquired Immunity – created by exposure to a specific microorganism, which is

“remembered” by the body’s immune system - Immunization – body’s ability to fight off certain

organisms is stimulated or enhanced

1. Active Immunization – contain either noninfectious fragments or whole pieces of

bacteria or viruses that have been weakened so they will not cause infection but will instead

cause the production of antibodies (vaccination)

2. Passive Immunization – antibodies against a specific infectious organism are given

directly to the person (vaccine may not be available)

External Defenses:

- Antibiotics – organic substances synthesized by microorganisms or at a lab used to treat

infectious diseases or to prevent them; each antibiotic is specific to a certain bacteria; can be

administered by mouth, vein, or muscle

- Hygiene – keeping a clean environment that limits exposure to infected bodily fluids,

decomposing material, or infected people will prevent the spread of infection


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The Heart- information taken from Holt McDougal text and PowerPoint’s.

30.3 The Heart and Circulation

• The heart has four chambers: two atria, two ventricles.

• Valves in each chamber prevent backflow of blood.

• Muscles squeeze the chambers in a powerful pumping

action.

aortic valve

left atrium

mitral valve

left ventricle

septum

pulmonary valve

right atrium

tricuspid

right ventricle


• Blood flows through the heart in a specific pathway.

1

2 4

3

1. The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle.

2. The right ventricle pumps blood to the pulmonary artery. This artery, which goes to the lungs, is the only artery in the

body that carries oxygen –poor blood. The blood enters the lungs, where carbon dioxide and water vapor diffuse into

the alveoli and oxygen diffuses into the blood.

3. Oxygen rich blood returns to the heart through the pulmonary vein and enters the left atrium. This is the only vein in

the body that carries oxygen-rich blood. As the atria contract, blood is pumped into the left ventricle, the largest

chamber of the heart.

4. When the ventricles contract, blood is pumped from the left ventricle into a large artery, the aorta, and is circulated

to the rest of the body.


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The heart pumps blood through two main pathways.

• Pulmonary circulation occurs between the heart and the

lungs.

– oxygen-poor blood enters lungs

– excess carbon dioxide and water

expelled

– blood picks up oxygen

– oxygen-rich blood returns to heart


• Systemic circulation occurs between the heart and the rest

of the body.

– oxygen-rich blood goes to organs,

extremities

– oxygen-poor blood returns to

heart

• The two pathways help maintain a

stable body temperature.


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Immune System- fights infection and pathogens

Skin= 1st line of defense, however you have holes where things can enter-> eyes, ears, nose,

mouth, and excretory organs-> therefore it needs EXTRA protection!

Mucous membranes= hair like cilia that are covered with sticky liquid to trap pathogens.

Once a pathogen gets in, the immune system relies on the circulatory system to send chemical

signals to coordinate an attack to send specialized cells to the infection site.

White Blood Cells

* Some material is from PowerPoint presentations taken from Holt McDougal resources.


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Three types of proteins fight off invading pathogens:

1. Complement proteins weaken pathogen membranes.

2. Antibodies make pathogens ineffective.

3. Interferons prevent viruses from infecting healthy cells.

Pathogens enter the body-> Basophils (in the blood stream) or Mast cells (in the tissues) release

chemical signals-> The signals attract other WBC’s to the infection site-> if the pathogen is a

parasite the eosinophils come and spray the parasite with poison-> If the pathogen is a virus,

bacteria, or fungus the neutrophils and macrophages (phagocytes) go to work and destroy the

pathogens by destroying them-> after phagocytosis the lymphocytes come in and finish the job.

Lymphocytes:

1. T-cells= destroy infected body cells.

2. B-cells= produce proteins that inactivate pathogens that have not yet infected a

body cell.

Proteins: fight off invading pathogens

1. Complement proteins-

a. Weaken the cell membrane of pathogens causing water to enter and then it

blows up!

b. Attract phagocytes to infected area.

c. Cause microbes to stick to blood vessel walls where they are easily found and

destroyed.

2. Antibodies-

a. Proteins made by B-cells

b. Bind to pathogens membrane-> inactive

c. Make them clump together-> easier to destroy

d. Activate complement proteins that weaken pathogen cell membrane.

3. Interferons-

a. Produced by body cells that are infected by a virus

b. Release enzymes that prevent viruses from entering and infecting

c. Inflammation response (nonspecific). Ex- scrape your arm-> it swells up because

that is your bodies way of keeping pathogens out.

Specific- occurs on the cellular level and is different for each pathogen

Nonspecific- Happens the same way to each pathogen

Antigens Inflammation Fever


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Inflammation- mast cells or basophils release histamines (chemicals) which cause blood vessel

walls to spread out-> fluids move out of the blood vessel into the tissues-> WBC’s squeeze out

of the capillary (tiny blood vessels between the larger ones) and move to the area of infection.

Once the WBC’s are out of the circulatory system the WBC’s go to work. When pathogens lose

the swelling goes down and tissue repair begins.

Fever- Mast cells and macrophages release chemicals that cause the hypothalamus to increase

body temperature. When your temperature is 103 the hypothalamus cannot regulate the

temperature and your enzymes stop working-> leads to seizures, brain damage, and death.

Antigens- proteins markers on the surface of cells and viruses that help the immune system

identify a foreign cell or virus.

Memory cells- specialized B and T cells that remember (immunity) an antigen that

invaded your body before-> destroyed but it makes you sick.

genetics- review...monohybrid- cross involving one trait. ex- tt x tt dihybrid- cross involving two...

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