Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

bio 220 > week 3 vocab > Flashcards

week 3 vocab Flashcards

1
Q

example of organisms with sex roles reversed

A

jacanas or seahorse

male incubates egg (more energetically invested), female compete and are more aggressive

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

sexual selection occurs when:

A

there’s a heritable variation of a trait that influences mating success or fertilization success

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

which sex often experiences stronger sexual selection?

A

the competing sex,

logic: non-competing can get with whoever they want, but competing one is limited. there’s more selective pressure on the limited one

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

elaborate traits usually occur in the ___ sex

A

competing

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

sexual selection can occur:

A

before or during/after sex

intrasexually or intersexually

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

example of intrasexual selection before mating

A

mooses

male-male or female-female competition for access

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

example of intersexual selection before sex

A

peacocks

display by competing sex for mating choice by non-competing sex

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

example of intrasexual selection d/a sex

A

frogs

compete to have their sperm fertilize egg

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

example of intersexual selection d/a sex

A

“cryptic mate choice”

female chicken can choose which sperm fertilizes their egg

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

intrasexual selection

A

individuals within a sex compete DIRECTLY for access to mates and their gametes

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

examples of evolution of traits for intrasexual selection

A

weaponry, fast sperm, sexual size dimorphism (competing sex is larger)

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

sexual size dimorphism

A

competing sex is larger

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

intersexual selection

A

indirect competition for access to mates and their gametes

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

what traits can help intersexually selecting organisms win access to mates?

A

mating displays and signals, courtship behavior, or genitalia

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

sexual selection is the result of:

A

direct or indirect competition for mates

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

benefits of sexual reproduction must ___ ___ ___

A

overcome non-trivial costs

pros of only passing on 1/2 of genetic material must be better than cons of potentially risking survival (colors of guppies finding balance between mating visibility and predation avoidance)

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

sexual selection often results in traits that ___ natural selection

A

oppose

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

where does natural variation come from?

A

mutations!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

process of including mutation in population

A

created, generates alleles, natural selection hopefully favors it, adaptive trait selected

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

selection ___ ___ ___

A

edits existing variation

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

genes are:

A

composed of DNA and specify how to build proteins

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

what are mutations caused by?

A

DNA copying errors, chemicals, or ionizing radiation

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

what is important about ionizing radiation?

A

it can’t affect gametes!

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

frequencies of mutations can change due to:

A

meiosis/recombination, natural selection, genetic drift, or gene flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
mechanisms that DECREASE variation
stabilizing selection, inbreeding, and genetic drift
26
"silent" or "synonymous" mutations
don't change the amino acid
27
"nonsynonymous" mutations
change the amino acids and potentially the function of the following protein, can then be acted upon by NS
28
what are the structural mutations that can occur?
deletion, duplication, inversion, fission, or fusion
29
mutation rates are very low! so...
mutations likely won't change allele frequencies in one generation
30
recombination during meiosis can...
exchange maternal and paternal chromosomes to produce new combinations more rapidly
31
what is the molecular clock?
Kimura's theory that most mutations are neutral we accumulate mutations constantly and we can use that to date how long ago different populations diverged a lot of DNA isn't used much (has since been disproven) and mutations of third codon don't always have an impact
32
phenotypic plasticity
a change in an individual's PHENOTYPE in response to their environment
33
natural selection example:
soapberry bugs introduction of new host plants with different fruit sizes, bugs shifted hosts NS resulted in beak adaptation to reach seed
34
what are the types of selection?
directional, disruptive, and stabilizing
35
directional selection
individuals with one extreme heritable trait are favored over others
36
example of directional stabilization
Darwin's finches in the drought
37
stabilizing selection
individuals with intermediate trait are favored
38
example of stabilizing selection
gall-making flies larvae produce galls on goldenrod plants, but large and small galls were targeted by predation, so intermediate size was favored
39
disruptive selection
individuals at either extreme of a phenotype are favored
40
example of disruptive selection
african seedcrackers (birds) small beaks can eat soft seeds, large can eat hard, but medium aren't optimal for either
41
what does stabilizing selection do?
maintain mean and reduce variance
42
what does disruptive selection do?
maintain mean and increase trait variance
43
what does directional selection do?
change mean and potentially reduce trait variation
44
sexual selection
selection due to within-population competition for access to mates and their gametes
45
sexual selection is responsible for:
more diverse and extravagant traits in nature, rapid evolution, and increased speciation
46
anthropomorphism
attributing human traits or intentions to non-human entities innate tendency that we should avoid with this content
47
sexual selection occurs as a result of ___
variation in mating success not everyone gets to mate or the same amount of mates
48
what causes variations in mating success?
competition
49
gametes are the ____
main difference between males in female
50
egg
large and sessile gametes
51
sperm
small and mobile gamete
52
sexual possibilities:
none (no gametes), two separate sexes (lions), hermaphroditism, sequential hermaphroditism
53
hemaphroditism
male and female gametes are produced in the same individual common in plants
54
sequential hermaphroditism
individuals start life as one sex and later transition into the other
55
sex roles
dependent on differences in parental investment between the sexes
56
higher parental investment ->
limiting sex, has mating preferences
57
lower parental investment
limited sex, has mating competition
58
anisogamy
differences in gamete size
59
our ancestral state is ___
isogamy
60
isogamy
single mating type, everyone can mate with everyone else all gametes same size universal compatibility
61
gamete trade-offs
large but slow/non-moving gamete with lots of resources vs. small but faster gamete with little resources
62
anisogamy is ___ distributed
disruptively
63
Bateman's principle
in most species, females invest more in reproduction than males, making them the limiting sex
64
male lifetime fitness is limited by...
how many mates they can obtain
65
female lifetime fitness is limited by...
how much resources they have available to allocate reproduction
66
result of Bateman's principle?
females can be the more choosy sex and males have to compete for them roles can be reversed!
67
can phenotypic plasticity evolve?
yes, it can be an adaptation ability to get fit more efficiently is heritable, but looking fit is not a heritable trait
68
reaction norm
range of phenotypic expressions of genotype across range of environments
69
example of phenotypic plasticity
male horned beetles use horns and body size to fight for females morphology determined by amount of food in larval period (small horns and body or large horns and body) why spend resources on large horns with small body if you'll lose anyways?
70
common garden experiment
individuals with different phenotypes are grown under same conditions
71
genetically controlled in CGE if...
individuals maintain their wild traits
72
phenotypic plasticity in CGE if...
individuals shift to similar traits
73
what is the purpose of common garden experiment?
distinguishing genetic variation from phenotypic plasticity
74
what are mechanisms that maintain genetic variation?
meiosis/recombination, natural selection, gene flow, disruptive selection, negative frequency-dependent selection
75
mechanisms that decrease genetic variation
stabilizing selection, inbreeding, genetic drift, positive frequency-dependent selection
76
frequency dependent selection
fitness of individual is dependent on its relative frequency amongst the population
77
positive frequency-dependent selection
majority phenotype wins, reduces genetic variation in population
78
example of positive frequency-dependent selection
poisonous butterflies favoring locally common butterflies of other poisonous ones
79
mullerian mimicry
two poisonous species mimic each other whatever looks like this won't get eaten
80
negative frequency-dependent selection
minority phenotype wins, promotes genotypic and phenotypic variation in population
81
example of negative frequency-dependent selection
purple/yellow morph flowers naive pollinators will switch between then as they find new reward (nectar/pollen)
82
sampling effects
changes in allele frequency over time that are random with respect to their function or selection
83
founder effect
loss of genetic diversity bc of migration even in which smaller group "founds" their own population
84
example of founder effect
less genetic diversity as humans spread out from Africa
85
bottleneck effects
loss of genetic variation from dramatic reduction in population size and then recovery from it, new population descends from small number
86
example of bottleneck effect
northern elephant seals hunting reduced population to 20-40 individuals, today have extremely low genetic variation
87
genetic drift
changes in allele frequencies in population due to chance events
88
random effects can lead to...
differences in numbers, sex ratio, or survival of offspring
89
genetic drift leads to...
evolution at random
90
example of genetic drift
beetles being crushed by shoe images
91
4 conclusions about genetic drift
its unbiased, affects smaller populations more, decreases genetic diversity over time, and generates divergence among populations imagine plots of multi-colored lines

bio 220 (11 decks)

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