Bio exam notes

evolution

change in characteristics of a species over several generations and relies on the process of natural selection

fossils palentology

hard remains are trapped in sediments that form at exposed envrionments that harded into rock

early evolution ideas

Plato

believed in perfect copies of every organism

DaVinci and Hooke

examined fossils to see that earths shape changed overtime

Curier

catastrophe made organisms extinct or taken over

Hutton

believed surface of earth is always changing

Lyell

any change in earth will always be slow

Lamareh

life is formed by non

Comparative Development: similarities and differences in featl development

Microbiology: not Darwins time, analysis of DNA

3 things for natural selection

1. Variation
2. Heritability
3. Reproduction Advantage

Darwin's theory of natural selection

species produce through offspring that survive pass on those traits to the next generation; appearance of organisms can be altered to adapt to new environments; andom chance allows existing traits to develop;

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pesticide resistance

genetic variation occurs in insects

antibiotics resistance

bacteria may havea genetic mutation so when one takes these antibiotics the weaker ones die

Random Change in DNA

no evolution occurs when

1. population is too big (bottleneck effect)

2. mating is random

3. no immigration

4. no natural selection/mutations

Genetic Drift

changes are frequent in an allele in population as a result of a chance event

bottleneck effect is when a big event reduces population the few survivors are the ones different from the rest

founder effect is when a small number of people go to start a new population

gene flow

when a number of species move from 1 population to the next

mutations

only source of new DNA, can be good, bad, or neutral

Selection

favours traits that have an advantage to their environment

4 patterns of natural selection

1. sexual selection: males vs. females, atrractive females

2. stabilizing selection

favours medium traits

3. directional selection

environement encourages a shift from the medium traits to a extreme traits

4. disruptive selection

environment encourages shift from mediums to both extreme traits

Formation of Species

group of reproductively compatiable organisms that have offsprings that are capabe of reproducing to evolve independently

environment causes organism to be so different its unable to breed together

offspring

Product of reproduction, get half traits from each parent

trait

characteristic of a parent that was passed down

genes

carries code for specific traits

DNA

makes up genetic material

nucleotides made up of phosphate group and ribose sugars (sides of ladder) and nitrogenous base (inside ladder: A

T, C

DNA duplication

when enzymes splits DNA like a zipper while the other enzymes match up the original nucleotides to new ones to create 2 new chromosomes

unravels to get coded since its so tightly packed

packaging DNA

contained in the nucleus as chromatin during cell divison it coils around proteins to form nucleotides which them form into chromosomes

mitosis

cell divison in normal cells when DNA is replicated

stages: interphase, prophase metaphase, anaphase, telephase, and cytokinesis

interphase

DNA is copied and prepares for divison

G1

growth

S2

synthesis, cell doubles it DNA

G2

cells grows to get ready for divison

prophase

nuclear membrane disappears DNA turns to sister chromatid held by centromere

metaphase

spindle fibers formed to push chromosomes together in the middle

anaphase

spindle fibers pull chromosomes/centromere apart to each end of cell

telephase

nuclear membrane begins to form again

Cytokinesis

cytoplasm divides creating 2 daughter cells

meiosis

sex cell division resulting in half as many chromosomes

meiosis 1

chromosomes double and divide to make 46 (23 pairs)

meiosis 2

resplit to have 4 cells with half chromosomes (23) DNA doesn't double

Males in Meiosis

spermatogenesis

1 master cell with 46 chromosomes divide 2 to form haptiod cells with 23 chromosomes

females in meiosis

most cytoplasm goes in 1 egg the rest (polar bodies) are broken up so only 1 egg is created, all eggs complete 1 divison but only complete the second when the egg is picked for maturation

crossing over

occus in first divison of meiosis and swaps mom and dads DNA to create diversity

protein synthesis

the formation of proteins by using information contained in DNA sicne DNA can't leave the nucleus, RNA takes messages from DNA through transcrption (mRNA) where it copies certain messages and takes it outside of nucleus. It then attaches to ribosomes (tRNA) where its translated. tRNA attaches to a amino acid to the ribosome to create a polypeptide chain to be released

hereditary

offsprings resembling parents

sex determination

males are XY, females are XX men carry only X and Y and women carry X and X. 50/50 chance of having a boy or a girl but Y swim faster but dont last as long whereas. X swim slower but last longer. IF the egg is lower higher chance of boy if egg is higher than higher chance of girl

mutations

sudden genetic change that alters your characteristics for future generations

can cause cancer

mutagens

chemicals that cause mutations (viruses, radiation, drugs)

mutations during meiosis formation

any outside influence can cause a mutation (x

mutations during fertilization

since delicate period of rapid cell division, any mutation can cause lots of harm

2 main types of mutations

chromosomes

affect chromosomes

gene

affects certain genes, point mutation, change in base changes the meaning of one part of the code

delection/insertation

removes single gene or adds one

5 main functions of circulatory system

1 transport oxygen and nutrients to cells 2 remove CO2 and waste from cells 3 maintain body temperature 4 circulates hormones

5 carry WBC for body defense

pulmonary circuit

right side of the heart, pumps blood to lungs (low pressure)

systemic circuit

left side of heart, pumps blood to body (high pressure)

coronary circulation

hearts own supply of blood, heart attacks are a result of these arteries being blocked

Simple transport system

breathe through simple diffusion ex. amoeba

O2 and sugar in and CO2 and H2O out

open simple transport

doesnt stay in tube, bloods not red, blood moves to heart by diffusion, many hearts to pump blood ex grasshopper

closed simple transport

blood remains in blood vessels, nutrients diffuse out of blood vessels into cells, waste diffuses out ex. worms

2 chambered hearts

slow circulation, blood mixes, not for large animals ex/ fish

3 chambered hearts

2 atria and 1 ventricle, little blood mix, ex frog

4 chambered hearts

never blood mix, two separate pumps, ex human

arteries

carry blood away from the heart, oxygenated, think walls because of high pressure called endothelium, 3 muscle layers: tunica intima

deeper in body, easy to bleed out because of pressure

veins

Carry deoxygenated blood back to the heart, lower pressure, walls are thin with same layers as arteries but thinner, contains valves to let blood flow one way towards the heart and prevent backflow, fights gravity so muscle movement help move blood up

capillaries

tiny blood vessels that connect arteries and veins, one cell think of endothelial cells, thin walled to allow diffusion of subatances, location of O2 and CO2 exchange by diffusion

SA node "pacemaker"

nerve cell that control heart rate by sending out signals impulses cause atria top contract

AV node "amplifier"

located in the septum

recieves signals from the SA node and transmits it to ventricles; delays impulse by 0.1 seconds so atria contracts first before sending out sugnal to ventricle to make them contract

Purkinje Fibers

nerve fibers that ensure the AV node signal reaches the bottom of the ventricles; causes heart to contract from bottom up and pushed blood out of arteries, bundle of HIS \= AV and purkinje

pulse

Beat of the heart as felt through the walls of the arteries, used to monitor heart rate and strength of heart, 54

blood pressure

pressure blood exerts on the walls of arteries as it flows

2 pressures measuered:

systolic

occurs when heart contracts, max pressure of heart

diastolic

occurs when heart relaxes, lowest pressure of heart

normal rate

120/80, ranges from 90

stethoscope

used to hear sounds

endocardiogram

ultrasound of heart