Brainscape's Knowledge GenomeTM

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


See full index

Biol > Population Genetics/Evolution > Flashcards

Population Genetics/Evolution Flashcards

1
Q

Define a population

A

A population is a group of organisms of the same species living in a specific region at a given time

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

Define species

A

Organisms are of the same species if they can breed to produce fertile offspring

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

Define subspecies

A

Different subspecies like a race can exist with the same species producing fertile offspring.

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

Types of variation

A 
Structural
Biochemical
Behavioural
Physiological
Environmental
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Formula for phenotype

A

genotype x environment

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

Despite phenotype being altered by environemntal pressures what remains the same?

A

The genotype

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

Define Monomorphic

A

Population is on which there exists only one variant of a trait

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

Define polymorphic

A

Population is on which there exists more than one variant of a trait

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

Define Continuous Variation

A

Where there are an infinite number of variants along a spectrum

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

Define Discontinious variation

A

When there are a discrete and finite number of variants.

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

List the causes of genetic variation

A
  1. Sexual Reproduction

2. Mutation

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

Explain how sexual reproduction contributes to geentic varation

A

a) crossing over to form recombinant genetical material
b) random assortment of chromsomes into gametes
c) combination of parents
d) combination of gametes at fertilisation`

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

Define gene pool

A

A sum and aggregation os all the alleles in all organisms for a particular population.

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

Define gene flow

A

Arrival of new individuals therefore new genes or alleles into a population therefore added to the gene pool.

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

What is essential for migration to affect allele frequency and the gene pool.

A

Requires the reproduction between individuals of different populations

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

Genetic Drift

A

Changes in allele frequencies that are unpredictable due to chance events.

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

Explain the bottle neck effect

A

Allele frequencies experience a sudden drop in population size i/e from a natural disaster. Allele frequencies drastically change in one go.
Surviving population is not nesscarily a representation of the orginal population.

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

Explain the founder effect

A

A group of individuals have emigrated from a larger population and have colonised and begun a new population. New population will be small

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

What does the enivronment select?

A

The favourable phenotype

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

Define adaptation

A

Inherited characteristics that increases chance on surivial

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

Define the process of natural selection

A

Involves the result in the surivival of the fittest organism that is best adapted to the environment and selective pressures.

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

Outline the steps in natural selection

A
  1. Phenotypic variation must exsist within the population
  2. In a changing environment one phneotype will be favoured. That phenotype will have an improved chance at surviving and reproducing.
  3. Therefore more offspring will obtain favoured characteristics
  4. Frequency of favoured alleles within the population will increase across generations.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Define selective advantage

A

A characteristic of an organism that enables it to survive and reproduce better than of others in the environment.

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

Define Artifical Selection

A

Humans select and breed organisms of their choice to obtain desireable features in the offspring.

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

Define evolution

A

Process by which over geological time, the heritable traits of the individuals of a population chance, leading to the advent of new species from previously exsisting species.

26
Q

Define Allopatric speciation

A

Whereby a new species is formed due to the geographical isolation of two populations of the same species.

27
Q

Explain the steps in speciation

A
  1. A geographical barrier must occur which seperate the population and cause gene flow to cease.
  2. Different selection pressures on either side
  3. Changes in the phenotypic characteristics in the populations are such that if the two populations where brought together they would unable to produce fertile offpsring. Hence new species has been formed
28
Q

Define extinction

A

A species is said to be extinct when there are no members of that species left alive

29
Q

Why does extinction occur most of the time?

A

Due to their being very few or no organisms that can adapt to a new selection pressure.

30
Q

Define divergent evolution

A

Where two species that are orignally closely related become more dissimilar phenotypically over time. More likely to have homologous structures due to sharing evolutionary relationships

31
Q

Define convergent evolution

A

where two independant species whom are distantly if related develop similar phenotypical chatacteristics due to encountering similar enivronmental and selection pressures. Tend to have analogous structures due to similar selection pressures

32
Q

Define homologous structures

A

Organisms with structures that have a similar pattern and are similar looking, due to a common ancestor or evolutionary origin. (More than likely have different functions)

33
Q

Define analogous structures

A

Different basic structure and look but will have the same function due to independent evolution.

34
Q

Define Vestigal Structures

A

Organs or features of an organism that are currentyl useless

35
Q

What are vestigal structures an indicator for?

A

A role previosuly existed for this feature in this organism for previous ancestors, therefore indicates evolution

36
Q

Explain comparative embryology

A

Organisms can look very different in an adult stage and can look very similar in an embryo stage
-From this it can be pressumed there was a common ancestor

37
Q

Explain the process of DNA hybridisation

A
  1. DNA is removed from two species and the double strand is broken and seperated via heating
  2. Seperate strands from different organisms are mixed
  3. Hybrid DNA molecule is then reheated to seperate strands
38
Q

What will a high temperature in DNA hybridisation indicate?

A

The larger the amount of temperature required the more hydrogen bonds it has, indicating that the strands are more complementary and therefore are more closely related.

39
Q

What are fossils evidence of?

A

Prehistoric life

40
Q

Where are fossils generally found?

A

Sedimentary rock

41
Q

What is sedimentary rock composed of?

A

mud, silt or sand

42
Q

What are direct fossils?

A

Actual remains

43
Q

What are indirect fossils

A

Not composed of any part of the original organism

44
Q

What are the layers of sedimentary rock called?

A

Strata

45
Q

What are the two forms of dating techniques?

A

Relative

Absolute

46
Q

What does relative dating technique involve

A

Fossils in rock strata that are closer to the surface are younger than fossils deep in strata

47
Q

What are index fossils used for?

A

To define and identify geological periods
Age of sediments that make up rock
Sediments where they were formed in seperate locations were deposited at roughly the same time.

48
Q

How old is the rocks that should be used fro carbon dating?

A

60,000 years

49
Q

Potassium-argon dating

A

500,000 + years

50
Q

Electron spin resonant

A

50,000- 500,000 years

51
Q

Ideal conditions for fossilisation

A
  • Oxygen poor
  • Buried quickly
  • High alkaline
  • no scavengers/predators
  • high pressure to compact sediment
52
Q

Explain the process of carbon dating

A
  • When an organism is alive the factor of carbon-14 to carbon 12 remains constant.
  • When the organism dies it stops ingesting carbon therefore carbon14 will continually decay over time.
  • Compare fraction of carbon 14 to 12 to determine how long ago it died
53
Q

Explain the process of potassium Argon dating

A

-Argon 40 in rock is determined

54
Q

How is genetic variation caused by sexual reproduction?

A
  • Crossing over (recombination)
  • Random assortment of chromosomes
  • Combination of parents
  • Combination of gametes
55
Q

Example of gene flow

A

Migration
Immingraion
emmigration

56
Q

What is an advanage of variation

A

Variation within a specifes improves the chances of the species surviving the environmental change

57
Q

What can selective forces be?

A

Biotic

Abiotic

58
Q

What populations are more like to suffer from extinction

A

Small inbreeding populations

59
Q

Define common ancestor

A

An organism from which two or more species have descended.

60
Q

Explain biochemical evidence in regards to evidence for evolution

A

-Antibody/antigen reactions can provide evidence of relationships
looking for degrees of similarity in chromosomes, amino acid sequences etc etc
Species more closely related if there are fewer differences

61
Q

What are transitional fossils

A

An intermediate fossil between then and now

Biol (22 decks)

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