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bio exam one Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

what is biology

A

scientific study of living organisms and fossils

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2
Q

common features of organisms

A

-common set of chemical compounds
-contain genetic info
-universal molecular code
-made up of cells
-use molecules from environment to synthesize new molecules
-regulate internal environment

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3
Q

Miller-Vrey Experiment

A

chamber with primitive ocean water + atmosphere and jolts of electricity combined molecules into RNA

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4
Q

Gregor Mendel

A

monk who discovered genes

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5
Q

genes

A

unit of genetic code that allows traits to be inherited

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6
Q

genome

A

total genetic code

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7
Q

when was DNA discovered?

A

mid-1900s

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8
Q

internal environment

A

-made up of extracellular fluid
-requires sensory mechanisms
-monitoring and regulation of intracellular environment

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9
Q

homeostasis

A

physical and chemical composition must be kept in a narrow range

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10
Q

2 types of cellular life

A

prokaryotic and eukyarotic cells

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11
Q

photosynthesis

A

transformation of sunlight into chemical energy to build molecules

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12
Q

consequences of photosynthesis

A

-oxygen built up in atmosphere
-aerobic processes are more efficient: evolution
-ozone layer developed
-blocked UV radiation on land and made life possible

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13
Q

population

A

groups of individual of same type of organism that interbreed

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14
Q

evolution

A

process resulting in changes in genetic makeup of populations over time

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15
Q

Charles Darwin

A

understood selective breeding and bred pigeons, produced idea of natural selection

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16
Q

speciation

A

traits can be more or less popular in populations, populations may split and preferences are embedded in each & ability to interbreed dissolves

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17
Q

classifications

A

genus + specific epithet

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18
Q

at organismal level, individuals must…

A

acquire nutrients from environment and break them down into building blocks

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19
Q

scientific method - observations

A

science is based on observations, experimentation, data analysis, and logic

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20
Q

steps of scientific method

A
  1. make observations
  2. ask questions
  3. form testable ideas
  4. make predictions
  5. test predictions
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21
Q

2 types of experiments

A

-controlled experiments manipulate 1 factor while holding other variables constant
-comparative experiments compare date from populations that differ in several ways

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22
Q

model species

A

we can use closely related organisms to model others
–common ancestry
–common genetic code
–similar building blocks

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23
Q

weather

A

short-term changes in atmospheric condition

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24
Q

climate

A

long-term patterns of changes of weather in a given area

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25
Q

evolution is…

A

-directly observable
-a universal principle of life
-a scientific theory
- a change in genetic composition of a population over time

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26
Q

natural selection (Darwin)

A

he observed that more offspring are born than can survive, natural selection=artificial selection

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27
Q

theory of evolution (species, divergent, differential)

A

-species change over time
-divergent species share a common ancestor
-differential survival and reproduction based on trait variation

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28
Q

what are mutations?

A

-any change in nucleotide sequences of DNA
-origin of genetic mutation
-most are harmful or neutral

random with respect to needs of organism and can restore variations other processes remove

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29
Q

gene pool

A

sum of all copies of all alleles at all locations in a population

mutations can cause different forms of genes to appear

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30
Q

mutation rates

eukaryotes + viruses?

A

rates differ in certain organisms, low mutation rates can still create a lot of variation

viruses acquire mutations rapidly, eukaryotes acquire mutations slowly

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31
Q

selection

A

differential survival/reproduction in a population; acts on genetic variation to produce new phenotypes

-can be artificial/natural/sexual

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32
Q

gene flow

A

the transfer of genetic material from one population to another, results in migration of individuals

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33
Q

genetic drift

A

the change in frequency of an existing gene variant, result of random changes in allele frequencies

harmful alleles may increase in frequency

34
Q

founder effect

A

a few individuals colonize an area, colonizing population likely will not represent all alleles

35
Q

nonrandom mating: sexual selection

A

individuals in a population chase mates with particular phenotypes

36
Q

genotype frequencies are…

and genetic structure is…

A

not always the same as allele frequencies

the allele frequencies at each locus

37
Q

Hardy-Weinberg: definition

A

model situation where allele frequencies do not change, provides baseline for testing evolutionary change

38
Q

Hardy-Weinberg: conditions

A
  1. no mutations
  2. no selection among genotypes
  3. no gene flow
  4. population size is infinite
  5. mating is random
39
Q

natural selection can…

A

-alter distribution of quantitative trait over time
-only act on phenotype

40
Q

fitness

A

how well a phenotype allows an individual to produce and contribute genetic material to the next generation

41
Q

qualitative

A

influenced by alleles at only 1 locus

42
Q

quantitative

A

shows continuous variation influenced by alleles at more than 1 locus

43
Q

stabilizing selection

A

preserves average phenotype, reduces variation but does not change mean, also purifying selection because there is selection against deleterious mutations

44
Q

disruptive selection

A

favors individuals that vary in both directions from the mean, individuals at either end are more successful

44
Q

directional selection

A

favors individuals that vary in one direction, happens when individuals at one end of a continuum are more successful, increases freq of alleles at favored phenotype, positive selection

44
Q

ways to maintain genetic variation

A
  1. neutral alleles
  2. sexual reproduction
  3. frequency dependent selection
  4. heterozygote advantage
  5. geographically distinct populations
44
Q

neutral alleles

A

alleles that do not affect fitness, added to populations by mutations, not directly acted on by natural selection

45
Q

sexual reproduction results in…

A

results in new combinations of genes through combination of gametes, crossing over, and independent assortment

46
Q

sexual reproduction disadvantages

A

-can break up adaptive gene combinations
-rate females pass on genes to offspring is reduces
-dividing offspring into sexes reduces overall reproduction rate

47
Q

sexual reproduction advantages

A

-facilitates repair of damaged DNA
-creates new combinations of alleles that natural selection can act on
-eliminates deleterious mutations

48
Q

Muller’s Ratchet

A

deleterious mutations can build up in asexual species and only death of lineage can eliminate them

49
Q

frequency dependent selection

A

fitness depends on frequency of a phenotype or genotype in a population

50
Q

heterozygote advantage

A

different alleles are advantageous under different environmental conditions, when conditions are changing heterozygous individuals outperform homozygous

51
Q

geographically distinct populations

A

populations in different areas are subjected to different environmental conditions and selective pressures, each population has its own variations on traits

52
Q

evolutionary outcomes are limited by…

A
  1. pre-existing traits
  2. constraints of natural world
  3. cost-benefit trade-offs
53
Q

pre-existing traits

A

-natural selection acts on phenotypic variation
-all evolutionary innovations are modifications of previously existing structures
-if allele for a trait doesn’t exist it cannot evolve

54
Q

constraints of natural world

A

-physics and chemistry limit potential variation
-cell size is constrained by surface area to volume ratios
-protein folding limited by types of molecular bonds
- energy transfer constrained by thermodynamic laws

55
Q

cost-benefit trade-offs

A

-adaptations pose costs and benefits
-benefits must outweigh costs for success
-can result in traits adaptive in one context but not another

56
Q

short-term evolutionary outcomes

A

changes in allele frequencies can be observed directly, manipulated experimentally, and demonstrate the actual processes by which evolution occurs

57
Q

long-term evolutionary outcomes

A

patterns of evolutionary change that can be influenced by extremely rare events, which cannot usually be observed during short-term studies

58
Q

phylogeny

A

evolutionary history of relationships among organisms

59
Q

phylogenetic tree

A

diagram reconstructing evolutionary history

60
Q

phylo trees can be constructed using…

A

physical structures, behaviors, biochemistry

61
Q

phylo trees can be about…

A

species, population, gene level

62
Q

root of phylo tree represents…

A

common ancestor

63
Q

(phylo) relative position of nodes shows…

A

timing of splitting events

64
Q

(phylo) ____ can be rotated around nodes

A

lineages

65
Q

(phylo) taxon

A

any species or group of species that we designate a name

66
Q

(phylo) clade

A

consists of an ancestor and all descendents of that ancestor

67
Q

(phylo) sister species

A

2 species that are each other’s closest relatives

68
Q

(phylo) sister clades

A

2 clades that are each other’s closest relatives

69
Q

ancestral trait

A

something present in ancestor of group

70
Q

derived trait

A

trait found in descendant that differs from ancestral trait

71
Q

homoplasy

A

traits shared by 2 or more species that were independently evolved

71
Q

(phylo) homologous traits

A

traits shared by 2 or more species inherited from common ancestor

72
Q

convergent evolution

A

independently evolved similar traits because of similar selective pressures

73
Q

evolutionary reversals

A

character reverts from derived state to ancestral state

74
Q

ingroup

A

group of primary interest

75
Q

outgroup

A

taxon outside ingroup to which ingroup is compared

76
Q

principle of parsimony

A

tree with fewest changes is preferred

biology (6 decks)

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