Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ecology > Ch 6 Exam 2 > Flashcards

Ch 6 Exam 2 Flashcards

1
Q

Genetic drift occurs when..

A

Random or chance events determine which alleles are passed to the next generation

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

What is a problem of small sample size?

A

Genetic drift

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

Genetic drift has four effects on small populations:

A
  • causes allele frequencies to fluctuate at random
  • reduces genetic variation
  • frequency of harmful alleles can increase
  • differences between separate populations can increase -> genetically “drift” apart

All by chance

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

Fixation

A

When an allele reaches 100% frequency or disappears completely

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

Loss of ___ ___ reduces ability of population to respond to changing environmental conditions.

A

Genetic variation

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

Increase of ___ ___ can reduce survival and reproduction.

A

Harmful alleles

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

Genetic or population bottleneck -

A

Population may experience sharp reduction in population size

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

___ may also decrease genetic diversity and spread deleterious alleles.

A

Inbreeding

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

Founder effect -

A

When only a small number of individuals migrate or are otherwise isolated from parent population

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

Gene flow -

A

Occurs when alleles are transferred from one population to another via migration or gamete dispersal

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

Migration -

A

Movement of individuals

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

Gamete dispersal -

A

Movement of gametes

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

Gene flow has two effects:

A
  • separate populations become more similar

- new alleles can be introduced into population from outside

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

___ ___ is the only evolutionary mechanism that consistently causes adaptive evolution.

A

Natural selection

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

___ are features of organisms that improve their ability to survive and reproduce in their environments.

A

Adaptations

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

Micro evolution -

A

Evolution on small scale on relatively short timeframe

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

Is natural selection a random process?

A

No

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

By consistently favoring individuals with certain alleles, natural selection causes ___ ___.

A

Adaptive evolution

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

Clines -

A

Gradual changes in a characteristic over a geographic region

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

Phenotypic plasticity -

A

One genotype produces different phenotypes in different environments

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

___ ___ can limit how well populations adapt to their environment.

A

Gene flow

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

Gene dilution -

A

Introduce alleles that are not adapted to local conditions

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

Natural selection does not result in..

A

A perfect match between organisms and their environment

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

Constraints on evolution:

A
  • lack of genetic variation
  • evolutionary history
  • ecological trade-offs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

___ does not drive mutation.

A

Need

26
Q

Example of constraint from lacking the right genetic variation

A

Initially, mosquito population lacked alleles that provided resistance to pesticides, so the pesticides were effective

27
Q

Example of constraint from evolutionary history

A

Dolphins evolved from terrestrial animals

They have lungs and cannot breathe underwater

28
Q

What are the creative processes in evolution?

A

Brings about great chances by modifying traits that are already present, not by creating advantageous traits

Selection is more of an “editing” process than a “creative” process

29
Q

Adaptations represent ___ in abilities of organisms to perform different and sometimes conflicting functions.

A

Compromises

30
Q

Example of constraint from ecological trade-offs

A

Trade-off between survival and reproduction in female red deer

31
Q

Adaptive evolution highlights connection between ___ and ___.

A

Ecology and evolution

32
Q

Long-term patterns of evolution are shaped by large-scale processes such as..

A
  • speciation
  • mass extinction
  • adaptive radiation
33
Q

Species -

A

Groups of organisms whose members have similar characteristics and can interbreed

34
Q

Speciation -

A

Process by which one species diverges into two or more species

35
Q

Speciation most commonly occurs when a ___ prevents gene flow between two or more populations of a species.

A

Barrier

36
Q

Key step in speciation is evolution of ___ ___ that prevent breeding with parental species.

A

Reproductive barriers

37
Q

Pre-zygotic -

A

Prevents mating or fertilization

38
Q

Post-zygotic -

A

occurs when population accumulates so many genetic differences that they cannot produce viable, fertile offspring if they mate with parental species

39
Q

Examples of pre-zygotic reproductive barriers -

A
  • geographic isolation
  • ecological isolation
  • behavioral isolation
  • temporal isolation
  • mechanical isolation
  • prevention of gamete fusion
40
Q

Examples of post-zygotic reproductive barriers -

A
  • hybrid embryos do not develop properly
  • hybrid adults do not survive in nature
  • hybrid adults are sterile or have reduced fertility
41
Q

Geographic isolation -

A

Species occur in different places

42
Q

Ecological isolation -

A

Species utilize different resources in the habitat

Fruit flies grown on different food sources

43
Q

Behavioral isolation -

A

Species have different mating rituals

Fruit flies get separated by lava, each evolve their own mating beats -> wings, stomping feet, rubbing of legs

Females will recognize beats of their species

44
Q

Temporal isolation -

A

Mating or flowering occur during different seasons or at different times of the day

Coral

45
Q

Mechanical isolation -

A

Structural differences prevent mating or pollen transfer

Duck penis is twirled so only fits in certain duck vaginas

46
Q

Evolutionary tree -

A

Branching diagram that represents the evolutionary history of a group

47
Q

The closest living relatives of pinnepeds are the ___ family.

A

Weasel

48
Q

Macroevolution -

A

Change over a large scale

49
Q

The first organisms were ___

A

Prokaryotes

50
Q

The oldest multicellular fossils are ___ years old.

A

2.1 billion

Red algae

51
Q

Animals first appeared how long ago?

A

600 million years

52
Q

A variety of fossils illustrate ___ ___ in the origin of tetrapods from fishes.

A

Transitional steps

53
Q

Fossil record documents ___ mass extinction events.

A

Five

54
Q

Increases in diversity over a relatively short time period are called __ __.

A

Adaptive radiations

Finches of the Galápagos Islands

55
Q

Soft-bodied animals predominant in the ___.

A

Precambrian

56
Q

Hard-bodied animals appeared during the ___ ___.

A

Cambrian explosion

57
Q

“Arms race” between predators and prey

A
  • early predators equipped with adaptations for capturing large prey provided powerful selection pressure that favored heavily armored prey species
  • that armor, in turn, promoted further increases in the effectiveness of the predators
58
Q

Coevolution -

A

reciprocal evolutionary change in interacting species

59
Q

Rise of a new species in one group can lead to increased diversity of other groups

Example :

A

When apples were introduced into North America

Some apple maggot fly populations switched from eating Hawthorn to apple

Probably forming a new species

60
Q

___ ___ leaves spatially isolated patches that can affect evolutionary processes.

A

Habitat fragmentation

61
Q

Human actions that affect environment can alter the three main mechanisms of evolution:

A

Natural selection
Genetic drift
Gene flow

62
Q

Speciation reversal -

A

Fusing two previously isolated species, and thus reducing biodiversity

Ecology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions