Unit 4 Topic 2 Bio

Question 1

What is Microevolution?

Answer 1

Changes in the gene or allele frequencies within a species. And is responsible for changes in a species genetic make-up in response to environmental changes.

Question 2

What is Macroevolution?

Answer 2

Evolution above the species level that encompasses increases in taxonomic diversity or morphological differences.

Question 3

Differences between Micro and Macroevolution.

Answer 3

Microevolution: Mutation, Natural Selection, Gene Flow, Genetic Drift.
Macroevolution: Genomic Divergence, Morphological Divergence, Taxonomic Diversity, Trends and Patterns.

Question 4

Summarise Darwin’s theory of evolution.

Answer 4

All species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual’s ability to compete, survive, and reproduce.

Question 5

What is Evolutionary Radiation?

Answer 5

The appearance of new forms or taxa (species diversification) over time.

Question 6

What are Comparative Genomics?

Answer 6

The comparison of genetic features to determine evolutionary relatedness.

Question 7

What is Molecular Homology?

Answer 7

A measure of the similarity of DNA and proteins of organisms.

Question 8

What is a Gene Pool?

Answer 8

All of the possible alleles for each gene of a population.

Question 9

What is Natural Selection?

Answer 9

Process whereby individuals with the most favourable characteristics have an increased chances of surviving and reproducing, compared with individuals with less favourable characteristics.

Question 10

What are Selection Pressures?

Answer 10

External factors that affect an organism’s ability to survive in a given environment

Question 11

What are Positive and Negative selection pressures?

Answer 11

Positive: Promotes the spread of beneficial alleles.
Negative: Hinders the spread of deleterious alleles.

Question 12

Three modes of selection are…

Answer 12

Stabilising, Direction and Disruptive.

Question 13

What is the Bottleneck Effect?

Answer 13

Catastrophic events or period of adverse conditions can dramatically decrease the size of the population.

Question 14

What is the Founder Effect?

Answer 14

A few individuals carry alleles to a new isolated area and a new population is formed with different alleles frequencies from the original population. Has less genetic diversity.

Question 15

What is Genetic Isolation?

Answer 15

Occurs when there is no gene flow between two population - the gene pools are isolated from each other.

Question 16

Prezygotic Isolating Mechanisms are…

Answer 16

Geographic. Temporal. Behavioural. Morphological.

Question 17

Postzygotic Isolating Mechanisms are…

Answer 17

Hybrid Inviability. Hybrid Sterility.

Question 18

What is Allopatric Speciation?

Answer 18

Occurs when a geographical barrier divides a population.

Question 19

What is Parapatric Speciation?

Answer 19

Occurs when populations maintain a zone of contact but the area is large with significant variation in habitat conditions.

Question 20

What is Sympatric Speciation?

Answer 20

Members within a population may have contact temporal or behavioural isolating mechanisms that reduce gene flow.

Question 21

What is Divergent Evolution?

Answer 21

The differentiation of distinctly different species/population from a common ancestral species.

Question 22

What is Convergent Evolution?

Answer 22

The evolution of similar features in unrelated groups of organisms. Features with similar functions that have evolved from different ancestral structures are termed ‘analogous’.