Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

AP Bio > Microevolution > Flashcards

Microevolution Flashcards

1
Q

Evolution-

A

genetic change in a

line of descent over the generations`

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Microevolution-

A

how populations of organisms change from generation to generation and how new species originate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Macroevolution-

A

patterns of changes in groups of related
species over broad periods of time- determine phylogeny, or evolutionary relationships among groups of
species–how different species are related

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Jean-Baptiste Lamarck–theories

A

Use and disuse, Inheritance of acquired characteristics, Natural transformation of species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Natural transformation of species-

A

because of the two above,
each generation of a species is transformed into a slightly different
more complex form
Ex- giraffe developed long neck from
stretched over time bc of necessity and this trait was passed to offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Inheritance of acquired characteristics

A

features that are

acquired during the lifetime of an organism can be passed on to offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Use and disuse

A

body parts of organisms develop more when used more, and unused parts weaken

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Charles Darwin–explanation

A

Because of strong check on populations because of limited food
supply, inherited variations that are favorable to survival will be preserved, others eliminated. (Adaptations.) Natural Selection.

Ex- Galapagos finches- 13 different species all descended from
one single species, but because of the different environment on each island, different
traits selected for, different species evolved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Adaptations

A

evolutionary modification that improves chances of survival in specific environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Natural Selection definition

A

better adapted organisms are more likely to survive, therefore population changes over time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Charles Darwin–aspects

A

Variation, Overproduction, Limits on population growth, Differential reproductive success,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Variation

A

individuals of a population exhibit variations,

some of which improve chances of survival and others which do not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Overproduction

A

every generation of a species has the

capacity to produce more offspring than can survive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Limits on population growth

A

struggle for existence

between individuals of a species because of limited resources

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Differential reproductive success-

A

individuals that are
best adapted to the environment (contain most favorable
traits) are more likely to survive and reproduce,
therefore their traits will pass on and others will die off

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Modern synthesis-

A

combines Darwin’s theory and Mendel’s theory to explain how these traits are passed on
Explains that variation is caused by mutations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Paleontology

A

studies fossils-remains or traces left in sedimentary rock by previously existing organisms.
Oldest layer at the bottom, upper layers are successively younger- allows scientists to place events recorded in rocks in their correct sequence.
Evidence of human life begins 100k years ago

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

halflife

A 
halflife--amount of
time it takes half
of substance to
decay
after 2 halflives,
25% will be left.
after 3, 12.5,
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Comparative anatomy-

A

in comparing structures from one organism to the next, scientists can discover how closely related they are

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Homologous features/ homology- (+ex)

A

features that are derived from the same structure in a common ancestor

Ex- human arm, cat forelimb, whale front flipper, and a
bat wing all have a similar arrangement of bones, muscles, and nerves,
even though they are all used for different types of locomotion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Homoplastic features (analagous)/ homoplasy-

A

structurally
similar features that are not homologous but have similar functions that evolved independently in distantly related organisms
can lead to convergent evolution

Ex- wings of insects and birds evolved in order to function in flight, but each evolved from different ancestors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Convergent evolution + ex

A

independent evolution of similar structures in distantly related organisms
Ex- aardvarks, anteaters, and pangolins all resemble one
another in lifestyle and structural features. All have strong, sharp claws, elongated snouts, long, sticky tongues, but each evolved from a different order

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Vestigial structures- + ex

A

organs that are nonfunctional or
undersized. These are remnants of more developed structures that were functional in ancestral organisms
Ex- in humans, the coccyx (fused tailbones), wisdom teeth, muscles that move our ears. (Usually not eliminated entirely)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Biogeography-

A

study of past and present geographic distribution of
organisms, which affects their evolution. Unrelated species can
therefore look alike when found in similar environments
can occupy different niches but if they live in the same habitat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
placental v marsupial
humans--placental--placenta forms, organ of exchange between mother and baby, meaning all development happens in utero in amniotic sac marsupial--give birth to immature baby which crawls out and up into the pouch, filled with tissue
26
Embryology + ex
“Ontogeny recapitulates phylogeny”- there are similar stages in development among related species (ontogeny). This helps establish evolutionary relationships recapitulates--teaches phylogeny--relationships gill slits and tails are found in fish, chicken, pig, human embryos
27
Molecular biology-
studies nucleotides and amino acid sequences of DNA and proteins from different species. Closely related species share higher % of sequences than species distantly related more than 98% of nucleotide sequence in humans and chimpanzees are identical
28
Stabilizing selection: ex
individuals with extreme or unusual traits are eliminated while individuals with the most common traits are best adapted Ex- larvae of certain fly bore into a plant and are enclosed in a tumor until they metamorphose into adults. Large tumors, or galls, are easily preyed on by woodpeckers, while small galls are preyed on by wasps. Therefore, flies that form intermediate galls are best selected for
29
Directional selection: ex
Favors traits that are at one extreme while traits at the opposite extreme are selected against Ex- insecticide resistance- the few insects that contain resistance to an insecticide will survive and produce offspring after several generations, population will consist of nearly all insectide-resistant Ex- peppered moth/ industrial melanism- before the industrial revolution, light-colored moths best camouflaged with the lichens covering the trees, while the dark colored moth was rarely found since it was easily preyed upon. After the industrial revolution, the lichens were killed, exposing the dark bark below. Therefore, the dark colored moths was now better camouflaged and it increased in frequency
30
Disruptive selection: + ex
Environment favors extreme or unusual traits while selecting against intermediate traits Ex- weeds exist in very tall forms in the wild because they can better obtain sunlight. However, in lawns, only short weeds exist bc these escape mowing middle ones=no selective advantage
31
Sexual selection:
Traits that allow males to mate with a large amount of females and maximize the quantity of offspring produced have a selective advantage and are passed on to offspring (male competiton) Females put a greater investment of energy into producing offspring, so they choose superior males leads to sexual dimorphism
32
Male competition
allows for mating opportunities to the strongest males, leading to the evolution of antlers and horns
33
Female choice
females choose traits or behaviors that | are attractive, like colorful feathers or elaborate mating behavior
34
sexual dimorphism-
differences in appearances of males and females within a species
35
Artificial selection + ex
Directional selection carried out by humans when breeding plants or animals that possess desirable traits Ex- certain breeds of dogs; brussel sprouts, cauliflower, and broccoli all come from one species of wild mustard
36
Gene flow
introduction or removal of alleles from a population when emigration or immigration occur
37
Genetic drift
random change in allele frequencies over generations brought about by chance. When populations are small, genetic drift has a greater effect and can influence evolution. 2 types.
38
Types of genetic drift
bottleneck + founder effect
39
bottleneck
when very few individuals rebuild a population after a severe reduction in population size
40
Founder effect + ex
type of bottleneck in which a few individuals leave a population and establish a new one somewhere else Ex--one of the founders of the Amish possessed allele for polydactyly and this trait now occurs at a large scale
41
nonrandom mating
individuals choose mates based on their particular traits which could be similar or different from their own
42
sexual selection
females choose males based on attractive appearances or abilities
43
inbreeding
nonrandom mating among closely related relatives, which have many alleles in common. lowers fitness (ability to form surviving offspring) of population
44
Mutations-->Variations
can invent new alleles that never previously existed
45
Sexual reproduction
allows for genetic recombination: Crossing over during prophase I, Independent assortment during metaphase I, Random joining of alleles during fertilization
46
Diploidy
more variation is maintained in a population because of the presence of two copies of every gene the recessive allele can be hidden but passed on
47
Outbreeding
mating with unrelated partners creates new allele combinations
48
Balanced polymorphism
maintenance of different phenotypes in a population
49
Heterozygote advantage
Individuals that are heterozygous have a greater selective advantage than either homozygous condition. Therefore-both alleles and all 3 phenotypes maintained in population
50
sickle cell anemia | Heterozygote advantage
Ex- sickle cell anemia- those that are homozygous for sickle cell (Hb S Hb S ) die before puberty. Those that have Hb A Hb A are normal. Those that are heterozygous- Hb A Hb S are generally healthy but have reduced oxygen- carrying capabilities during exercise. However- in Africa 14% of population are heterozygous bc of a selective advantage making them resistant to malaria
51
Frequency dependent selection (minority advantage)- + ex
when least common phenotypes have a selective advantage. However, they soon increase in frequency and lose their selective advantage phenotypes therefore alternate between the two Ex- predators form a “common representation” of their prey in order to optimize its search. Prey that rare escapes until it's no longer rare
52
Neutral variation-
variation that does not have a selective advantage or disadvantage
53
Genetic equilibrium
when frequency of alleles in a population remains constant from generation to generation
54
In order for equilibrium to occur, the following conditions must be true
random mating and no genetic drift, gene flow, mutations or natural selection
55
P
frequency of dominant allele
56
Q
frequency of recessive allele
57
p2
frequency of homozygous dominant individuals
58
q2
frequency of homozygous recessive individuals
59
pq + qp = 2pq
frequency of heterozygous individuals
60
hardy-weinberg equations
p + q = 1 (sum of all alleles = 100%) | p 2 + 2pq + q 2 = 1 (sum of all individuals = 100%)
61
if the population is at equilibrium, what will happen to frequencies?
frequencies will be the same in every generation
62
In most natural populations, are the conditions observed?
not obeyed
63
What does it mean when the genotypes and phenotypes are in different proportions?
one of the conditions isn't being met

AP Bio (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions