Life Science 15 Phelan

evolution

a change in allele frequencies over time

allele

one variant of a gene

gene

section of DNA instructing how to produce a trait

natural selection

variation, heritability, differential reproductive success

fitness

the relative reproductive success of a genotype or phenotype

4 agents of evolutions

natural selection, mutation, gene flow, genetic drift

natural selection

non-random elimination of alleles

mutation

a direct alteration of DNA so that one allele is changed into another

migration/gene flow

change in allele frequencies because some members leave and others arrive

genetic drift

a random change in allele frequencies, will occur mostly in small populations

sexual selection

traits that are more desirable to the opposite sex are selected for. trade-offs

norm of reaction

relationship between nature and nurture in producing phenotypes, one genotype producing multiple phenotypes in different environments

mendel

inheritance of pea plants

homologous pair

two versions of the same gene (one from father, one from mother)

karyotype

picture of all chromosomes in a cell

mendels' law of segregation

a gamete receives only one allele from the pair of alleles possessed by an organism

law of independent assortment

the allele you pass for one trait has no effect on which you pass for another trait

test cross

a cross between an organism whose genotype for a certain trait is unknown and an organism that is homozygous recessive for that trait so the unknown genotype can be determined from that of the offspring

methods of sex determination

male/female heterogamety, ploidy, incubation temperature

why does kindness occur?

shared genes/kin selection, reciprocal altruism

two ways to increase a gene's market share

direct and indirect fitness make an allele more prevalent in a population

hamilton's rule

evolution to favor a behavior, the cost to the giver must be less than the benefit X the coefficient of relatedness

methods of kin recognition

spacial association, social association, phenotype matching

ploidy

# referring to # of chromosome sets present in a cell. haploid (gametes) =23, diploid (all others) =46

codominance

A condition in which both alleles for a gene are fully expressed

what conditions are conducive to reciprocal altruism?

repeated interactions, high benefit to recipient relative to the cost, ability to punish cheaters

ways of enhancing cooperation

tinkering with perceived costs and benefits, distinguish cheaters and kind people, reduce perceived vulnerability of partners (that they won't get paid back)

altruism

apparently selfless behaviors for the welfare of others or oneself

mitosis

all genetic material from a diploid cell is duplicated

meiosis

all genetic material from a haploid cell is copied and forms new gametes

DNA fingerprinting

process of comparing genetic material to determine DNA linkage

null hypothesis

stating that two things do not have a relationship

superstition

irrationally believing that certain actions can influence an outcome

empirical knowledge

based on experience and observations that are testable, rational, and repeatable

hypothesis

a proposed explanation for a phenomenon

variables

characteristics of an experiment that are subject to change

pseudoscience

scientific-sounding thinking that isn't supported by study

DNA

deoxyribonucleic acid; made up of nucleotides with three components- phosphate group, sugar molecule, base

homozygous genotype

when an individual inherits the same two alleles for a gene

heterozygous genotype

when an individual inherits two different alleles for a gene (one from each parent)

carrier

has allele but doesn't exhibit it

incomplete dominance

phenotype of a heterozygote is intermediate between the phenotypes of the homozygotes

multiple allelism

a single gene has more than 2 alleles

universal donor

O blood type

universal recipient

AB blood type

polygenic

traits influenced by many different genes

additive effects

outcome when alleles from multiples genes all contribute to the ultimate phenotype (e.g. behavior)

pleitrophy

single gene that affects one or more trait

two special cases of genetic drift

founder effect and population bottleneck effect

founder effect

small number of individuals leave population and become the sole members of a new, isolated one

population bottleneck effect

rapid environmental change results in death of large portion of individuals

hardy-weinnberg law

a trait doesn't decrease in frequency because it's recessive...as long as individuals aren't dying off from it

artificial selection

a form of NS, but the reproductive success is determined by humans rather than nature

directional selection

individuals with ONE extreme of the variation have higher fitness

stabilizing selection

individuals with intermediate phenotypes are the most fit

disruptive selection

individuals with the extreme phenotype are the most fit, those with intermediate are the least fit (coho salmon)

evidence of evolution

the fossil record, biogeorgaphy, comparative anatomy/embryology, lab and field studies

innate behaviors

instinctive, don't require environmental input

fixed action pattern

sequence of behaviors that requires no learning, doesn't vary, and is continued until completion once started

sign stimulus

triggers a fixed action pattern

prepared learning

when behaviors are learned easily by all

group selection

behaviors that are good for the population but detrimental to the individual

reproductive investment

energy spent taking care of offspring is always higher for the female because their gametes are larger

polygamy

some individuals have multiple mates while others have none

polygyny

males mate with multiple females

high variance of male r. success/low variance in female r.s.

polyandry

females mate with multiple males

low variance in male RS/high variance in female RS

pair bond

male and female spend a lot of time together, share "nest," and contribute equally to care of offspring

three types of communication

chemical, acoustical, visual

chemical communication

molecules (pheromones) released into the environment triggers a response

acoustical communication

sounds that trigger a response

visual communication

visual signs trigger a response

nature vs. nurture

debate concerning the relative importance of individuals' innate qualities (nature) vs. personal experiences (nurture) in determining differences in physical/behavioral traits

lipids

not water soluble, major storehouses of energy, good insulators, three types- fats/triglyceroids, phospholipids, steroids

food preferences

foods our bodies think will improve our fitness

carbohydrates

function=fuel, structure=carbon, 2 hydrogen, oxygen

monosaccarides vs. polysaccharides

mono- fast energy, readily available. simple sugars/carbs, glucose/fructose

poly-2 step process: must fist be released from long chain then broken down; good for storage and long release of energy. stored in liver/muscle cells for a day before being broken down

proteins

function=construction, building new tissue, also act as enzymes and catalyze reactions

structure=repeating units of amino acids (amino+carbon group)

amino acids="building blocks of protein"

2 reasons for eating

fuel for constant chemical reactions and raw materials needed for growth

digestion

the process of chemically/physically breaking down food into its macromolecular components

nutrients

the usable materials in our food- carbs, lipids, proteins, vitamins/minerals, water

body weight

balance between the energy carried in the molecular bonds of food and the energy burned while living

calories

measure of the energetic value in food, energy needed to raise temp of 1 g of water by 1 degree celsius

basal metabolic rate (BMR)

amount of energy expended at rest, with no food in digestive tract, in a neutral temperature

humans=1 cal/hour/g. of body weight

how to calculate caloric needs

body weight x energy needed each hour x hours/day

water

transports nutrients/waste throughout body, takes part in chemical reactions, solvent for many amino acids/vitamins/minerals/sugars, lubricates joints/spinal cord/eyes, regulates body temp

essential amino acids

8 we must get from food

non-essential amino acids

12 that humans can make

saturated fats

solid at room temperature, more likely to be stored, no kinks in tails

unsaturated fats

kinks in tails (double bonds between carbons), can't pack together closely, liquid at room temperature, less likely to be stored

vitamins

organic compounds, essential nutrients required by the body in small amounts for normal health/growth

minerals

chemical/inorganic elements, some of which are required in small amounts in the diet

water soluble vitamins

B, C

fat soluble vitamins

A, D, E, K

digestive process

ingestion>digestion>absorption>elimination

ingestion

the intake of food into the body involving the mouth, teeth, tongue, and esophagus

trachea

(windpipe) connects to lungs, involved in ingestion of food

esophagus

connects to stomach, involved in ingestion of food

peristalsis

waves of smooth muscle contractions that propel food down esophagus and into stomach

sphincter

point where esophagus connects to stomach, ring of muscle

3 functions of stomach

1)physically breaks down food through churning of muscles 2) secretes acid to chemically break down/kill bacteria 3) begins chemical digestion of proteins