Brainscape's Knowledge GenomeTM

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


See full index

EVOLUTION > Population Genetics (4) > Flashcards

Population Genetics (4) Flashcards

1
Q

Population genetics?

A

= the study of genetic variation in populations and how it changes overtime.

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

Population genetics is =…+…? Explain.

A

PG = NS + Genetics
Where:
• NS - individuals in ecosystems with P(fixation) via selection, drift, migration.

• Genetics - molecules in individuals with P(change) via mutation, recombination.

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

Population?

A

= a localized group of individuals that are capable of inbreeding and producing fertile offspring.

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

Gene pool?

A

= the total number of genes/alleles present in a population at any time.

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

What models pop up when talking about Population genetics? (2)

A

• Modern evolutionary synthesis/ Neo Darwinism.
• Hardy-Weinberg principle.

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

What is the Modern synthesis primarily about?

A

It shows that both mutation & NS caused adaptive evolution in populations.

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

> = 2 alleles in a population =…? (2)

A

• Homozygotes.
• Heterozygotes.

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

1 allele in a population = …?

A

Homozygotes only (“fixed” in population).

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

What do the 3 Mendelian laws tell us?

A

They tell us how alleles are inherited in subsequent generations.

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

What 2 things do we focus on in Mendelian inheritance?

A

• Diversity.
• Segregation.

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

What does allele arrangement affect? (2)

A

• Diversity.
• Segregation.

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

Mendelian laws? (3)

A

• Law of Segregation.
• Law of Independent assortment.
• Law of Dominance.

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

Law of Segregation?

A

= alleles segregate from each other, so each gamete only carries one allele for each gene.

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

Eg of Segregation law?

A

Gene in seeds of pea plants exists in 2 forms where one allele is for yellow (Y) seed colour & the other is for green (y) seed colour.

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

Eg of Independent Assortment law?

A

Drosophila (fruit fly) eye colour & wing curl.

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

Eg of Dominance law?

A

When pea plants with round seeds (RR) are crossed with plants with wrinkled seeds (rr), all seeds in the next generation were found to be round (Rr).

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

Effect of the Mendelian laws?

A

All laws affect how alleles are inherited in subsequent generations.

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

Types of Dominance? (3)

A

• Complete dominance.
• Incomplete dominance.
• Co-dominance.

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

Complete dominance?

A

= where one allele is dominant over the other such that one cannot distinguish between homozygous dominant & heterozygous when expressed in the phenotype.

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

In the eg of flower colour, what colours would the flower be in each type of dominance? (3)

A

● Complete dominance.
= Red/Magenta.

● Incomplete dominance.
= Pink.

● Co-dominance.
= Red/Magenta & White (“marbled” phenotype).

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

How do populations evolve?

A

Through allele frequencies changing over time.

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

Hardy-Weinberg principle?

A

= states that the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors.

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

Ho & H1 in the Hardy-Weinberg principle?

A 
Ho = population genetics.
H1 = evolutionary processes.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What 2 things will remain constant in subsequent generations under the 5 assumptions of the Hardy-Weinberg principle?

A

• Genotype frequency.
• Allele frequency.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In real life/reality, what happens to allele frequency? (2)

A

• It changes over time.
• Does not remain constant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Why are genotypes formed at a frequency ratio of p²: 2pq: q² ?

A

Random mating.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the 2 equations relating to the Hardy-Weinberg principle?

A

● p + q = 1

● p² + 2pq + q² = 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Application of PG & Selection/ Heterozygotes & Stabilizing selection?

A

Seen in individuals with sickle cell anaemia where such individuals have a heterozygous advantage via Hb^A Hb^S.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Conditions/assumptions for the H-W principle/H-W equilibrium to work? (5)

A

• No NS.
• No mutations.
• Random mating (No SS).
• Infinitely large population so that genetic drift is not prominent.
• No gene flow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Types of mutations? (4)

A

• Point mutations.
• Indel mutations.
• Aneuploidy.
• Polylpoidy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Point mutations?

A

= where there are changes in one nucleotide pair of a gene.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The 2 types of point mutations? Explain them.

A

● Synonymous.
= same amino acid produced.

● Non-synonymous.
= different amino acid produced.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Indel mutation?

A

= mutations that involve the insertion or deletion of a portion of the chromosome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Aneuploidy?

A

= a chromosomal abnormality where one or more chromosomes are present in extra copies or are insufficient in number.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Polyploidy?

A

= when an organism has >2 complete sets of chromosomes in its somatic cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

The 2 common violations of Random mating?

A

• Assortative mating.
• Inbreeding.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Types of assortative mating? (2)

A

• Positive assortative mating.
• Negative assortative mating.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Eg of Positive assortative mating?

A

Beetles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Inbreeding?

A

= event where individuals are more likely to mate with relatives than non-relatives.

40
Q

Results of inbreeding? (3)

A

• Decreased variance.
• Increase in frequency of homozygosity.
• Decrease in frequency of heterozygosity.

41
Q

Results/Effects of genetic drift? (3)

A

• Smaller populations are more affected.
• Increased effect as population size decreases.
• Reduces genetic variation over time.

42
Q

Eg of random mating?

A

Coral spawning.

43
Q

Scenarios that increase the prevalence/frequency of genetic drift? (2)

A

• Bottleneck effect.
• Founder effect.

44
Q

Bottleneck effect?

A

= where the parent population is struck by a disaster, few survivors exist & the genes are no longer representative of the original population.

45
Q

Which is genetically poor between the bottleneck effect & the founder effect?

A

Bottleneck effect.

46
Q

Eg of bottleneck effect?

A

Cheetahs.

47
Q

Founder effect?

A

= where few individuals are isolated from a larger population.

48
Q

Egs of How the individuals are isolated on the Founder effect? (3)

A

• A river changes course.
• Seeds are dispersed to a mountain top.
• Birds are blown to a different island.

49
Q

Result of Founder effect in humans?

A

Polydactyly.

50
Q

Gene flow?

A

= the exchange of gametes as individuals move & reproduce.

51
Q

Population genetics = … + … ?

A

PG = NS + Genetics.

52
Q

PG attributes? (4)

A

• Foundation of studying genetics.
• Starts with the Modern (Evolutionary) synthesis.
• Incorporated into evolutionary theory.
• Composed of populations & gene pools.

53
Q

Who developed the evolutionary theory? (3)

A

• Fisher.
• Wright.
• Haldane.

54
Q

Fundamental units of PG? (3)

A

• Homozygous dominant (AA).
• Homozygous recessive (aa).
• Heterozygous (Aa).

55
Q

Law of Segregation attributes? (2)

A

• Deals with alleles.
• Generates a unique combination of alleles.

56
Q

Law of Independent Assortment?

A

= genes for different traits separate independently during gamete formation.

57
Q

Law of Independent assortment attributes? (5)

A

• Generates a different combination of traits.
• Deals with genes, not alleles.
• Increased genetic variation.
• Linkage violates independent assortment law.
• If genes are near each other they’re inherited together.

58
Q

What violates the Law of Independent assortment?

A

Linkage.

59
Q

How does linkage violates the Law of Independent assortment?

A

Through linked genes not being able to separate from each other.

60
Q

Law of Dominance?

A

= where one allele is expressed more strongly than the other allele.

61
Q

Law of Dominance attributes? (2)

A

• Interactions between alleles.
• More of a principle.

62
Q

Incomplete dominance?

A

= where an intermediate of the 2 alleles is observed in the phenotype.

63
Q

Co-dominance?

A

= where each parental phenotype is expressed in the offspring (co-expression).

64
Q

Incomplete dominance is AKA?

A

Partial dominance.

65
Q

How do we know if a population is evolving?

A

We test for evolutionary processes by observing individuals in generations over time.

66
Q

How do we test for evolutionary processes?

A

We use the Hardy-Weinberg principle.

67
Q

Hardy-Weinberg principle origins/background? (2)

A

• Developed independently.
• Developed by mathematicians with little understanding of biology.

68
Q

Hardy-Weinberg principle in a nutshell?

A

= describes a hypothetical population that is not evolving.

69
Q

Hardy-Weinberg principle attributes? (4)

A

• Termed “H-W Equilibrium “.
• Ho is in PG.
• H1 are evolutionary processes.
• In a real population, allele & genotype frequencies change over time.

70
Q

H-W principle in terms of equations? (2)

A

• Given either genotype frequency or allele frequency, you can predict the next generation if a population is not evolving.

• Can be extended to >= 3 alleles.

71
Q

Elaborate symbols behind equation:

p² + 2pq + q² = 1

A

p² = Homozygous dominant genotype.2pq = Heterozygous genotype.
q² = Homozygous recessive genotype.

72
Q

Elaborate symbols behind equation:

p + q = 1

A

p = frequency of dominant allele (A).
q = frequency of recessive allele (a).

73
Q

p² + 2pq + q² = 1 represents what?

A

Genotype frequencies.

74
Q

p + q = 1 represents what?

A

Allele frequencies.

75
Q

When will the original frequency remain constant?

A

If the 5 assumptions are upheld/met.

76
Q

Evolutionary processes affecting evolution? (5)

A

• NS.
• Mutations.
• Non-random mating.
• Genetic drift.
• Gene flow.

77
Q

Why aren’t we all X-folks?

A

It’s because mutations are often deleterious & not fixed in populations.

78
Q

Eg of Assortative mating?

A

Blister beetles
- mate with partners of the same size.

79
Q

Law associated with Assortative mating?

A

The Greenbeard Effect.

80
Q

Positive Assortative mating?

A

= similar individuals mating.

81
Q

Negative Assortative mating?

A

= unlike individuals mating.

82
Q

Eg of Negative assortative mating?

A

Moths.

83
Q

Egs of Non-random mating? (2)

A

• Assortative mating.
• Inbreeding.

84
Q

Bottleneck effect attributes? (3)

A

• Some alleles would be over-represented or under-represented.
• Results in a genetically poor population.
• Results in inbreeding.

85
Q

Results of Bottleneck effect? (2)

A

• Genetically poor population.
• Inbreeding.

86
Q

How are Chertahs an eg of Bottleneck effect? (3)

A

• Experienced 2 disasters.
• Low genetic variation between Southern Africa & Eastern Africa cheetahs.
• Have low sperm count & morphological abnormalities.

87
Q

Founder effect attributes? (2)

A

• New gene pool is not reflective of the source population.
• Founders pass through a “Isolation bottleneck”.

88
Q

Eg of Founder effect in Humans?

A

Armish people.

89
Q

How are Armish people an eg of Founder effect in humans?

A

Through them being an isolated group of German founders.

90
Q

Eg of Founder effect in animals?

A

French snails.

91
Q

How are French snails an eg of Founder effect in animals?

A

Through them arriving at Australia & Rottnest island.

92
Q

Egs of Founder effect? (2)

A

• Armish people (polydactyly).
• French snails.

93
Q

Gene flow attribute?

A

Common process of evolution.

94
Q

How do we evaluate if a population is a HWE? (2)

A

• Compare observed number of genotypes in a population with expected number of genotypes to see if the population was in HWE.

• Use chi² analysis.

95
Q

Why do we use chi² analysis?

A

To test for goodness of fit of Ho (null hypothesis).

EVOLUTION (12 decks)

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