Evolution And Processes

Question 1

What is the definition of evolution?

Answer 1

A change in a gene pool of a population over time.

Question 2

What is the definition of a gene pool?

Answer 2

The gene pool is the total set of alleles present in a population.

Question 3

How do you calculate an allele frequency?

Answer 3

Total number of a particular genes alleles. Over. The total number of alleles in a gene pool for that population.

Question 4

What is genetic drift?

Answer 4

Genetic drift is the increase in frequency of some alleles and the decrease in frequency of other alleles.

Question 5

How does genetic drift change the gene pool?

Answer 5

Allele frequency’s can change therefore changing the gene pool.

Question 6

What determines the effect that genetic drift has on a population?

Answer 6

Genetic drift will have a bigger effect on smaller populations.

Question 7

What causes genetic drift?

Answer 7

Genetic drift occurs through reproduction as offspring will have different combinations of alleles and may change the allele frequency’s which can change the gene pool.

Question 8

What is the founder effect?

Answer 8

The founder effect occurs when a small group of a larger population moves away and establish‘s it’s own gene pool.

Question 9

What happens during the founder effect?

Answer 9

Two things will happen.

1. The smaller population will have a similar gene pool to the original population
2. The smaller population will have a different gene pool to the original population.

Question 10

Why will the gene pool of the small population during the founder effect likely be different to its original population?

Answer 10

The small population is only a small sample of the original population therefore it is more likely the ratio of alleles will be different.

Question 11

What is the bottle neck effect?

Answer 11

When a population greatly reduces in size due to a sudden change to its environment.

Question 12

What happens to the size of the population during the bottleneck effect?

Answer 12

Reduces

Question 13

What are the effects that the bottleneck effect has on a populations genetic diversity?

Answer 13

It reduces a populations genetic diversity as there is only a small sample of the population left and there is less genetic variety.

Question 14

What is the importance of Variation in a population?

Answer 14

To ensure the population has a range of different alleles present for different selection pressures they may face. (Better advantage against change)

Question 15

What are the sources of variation?

Answer 15

Meiosis (Independent assortment, crossing over & segregation), Mutations.

Question 16

True or false? Beneficial mutations ar extremely rare

Answer 16

True

Question 17

True or False? Mutations are the only source of new alleles?

Answer 17

True

Question 18

True or False? Mutations selected against will stay in the gene pool?

Answer 18

False

Question 19

True or False? Natural selection does not determine whether a mutation is advantageous or not?

Answer 19

False

Question 20

What is gene flow?

Answer 20

Gene flow is the movement of alleles in or out of a gene pool/population, usually by migration.

Question 21

What is natural selection?

Answer 21

An Individual’s ability to survive selection pressures from their environment and reproduce successfully passing on their advantageous genes.

Question 22

What is Stabilising selection?

Answer 22

When the median phenotypes are selected for while the extreme phenotypes are selected against.

Question 23

What is disruptive selection?

Answer 23

When the extreme phenotypes are selected for while the median phenotypes are selected against.

Question 24

What is Directional selection?

Answer 24

When a particular extreme phenotype is selected for.

Question 25

What is sexual selection?

Answer 25

Exaggerated traits which increase an organism’s ability to have successful reproduction.

Question 26

What are vestigial structures?

Answer 26

Organs, tissues, bones or structures in an organism that are functionless as they only served as beneficial for the ancestors of that organism.

Question 27

What are the 5 evidences of evolution?

Answer 27

Fossils, Biogeography, Comparative Anatomy, Molecular Biology and the MtDNA & Y chromosome.

Question 28

How do Fossils show evidence of evolution?

Answer 28

They show the changes over time through the preserved remains of different species.

Question 29

How does Biogeography show evidence of evolution?

Answer 29

It maps the geographical distribution of species over time.

Question 30

How does Comparative Anatomy show evidence of evolution?

Answer 30

It is the investigation of Vestigial, homologous and analogous structures. These are identifiers that evolution has occurred.

Question 31

How do the MtDNA and y Chromosome show evidence of evolution?

Answer 31

The study of these can help to find where and when mutations have occurred leading to evolutionary changes.