18 - Populations and Evolution Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

gene pool

A

all the alleles of all the genes of all the individuals in a population at a given time

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

allelic frequency

A

number of times an allele occurs within the gene pool

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

use of Hardy-Weinberg principle

A

used to predict the proportion of dominant and recessive alleles of any gene in the population, provided the population remains the same from one generation to the next

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

conditions required for Hardy-Weinberg

A
no gene mutations
no immigration
no emigration
large population
random mating between individuals
all genotypes have the same reproductive success
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

effect of population size on the impact genetic drift on a population’s genetic diversity and evolution

A

greater population size, smaller impact of genetic drift on a population’s genetic diversity

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

genetic variation arises as a result of

A

mutation
meiosis
random fertilisation of gametes

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

selection pressures that limit the population of a species

A

predation, disease, competition, food, light, space

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

evolution by natural selection depends on

A
  1. over production of offspring
  2. genetic variation within populations of all species
  3. phenotypic variation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

over production of offspring

A

death rates must be high as populations rarely increase exponentially
some species have lower reproductive rates but increased parental care in order to maintain population
intraspecific competition for aailable resources
death isn’t random

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

disruptive selection

A

selection pressure towards the extreme values creates two modal values

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

stabilising selection

A

selection pressure towards the central value increases the number of individuals at the modal value

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

directional selection

A

selection pressure towards one xtreme value moves the mode in this direction

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

speciation

A

the evolution of new sppecies fro existing ones, often caused by geographical isolation and different selection pressures acting over many generations

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

allopatric speciation

A

speciation caused by geographical separation

  1. environmental conditions on either side of the geographical barrier vary
  2. natural selection influences the two populations differently
  3. each evolves in different ways leading to adaptations to their local conditions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

sympatric speciation

A

speciation caused by reproductive separation within the same population

  1. different individuals of the same species start utilising a new resource or area
  2. mate with other individuals in this area
  3. over time mutations arise which lead to genetic differences
  4. results in unsuccessful breeding between the different groups of individuals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly