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 is Extinction?

Answer 6

The loss of all populations of a species or a group of species.

Question 7

What is Mass extinction?

Answer 7

An event characterised by the disappearance of large number of species in a relatively short time frame.

Question 8

What are Comparative Genomics?

Answer 8

The comparison of genetic features to determine evolutionary relatedness.

Question 9

What is Molecular Homology?

Answer 9

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

Question 10

What is a Gene Pool?

Answer 10

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

Question 11

What is Natural Selection?

Answer 11

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

Question 12

What are Selection Pressures?

Answer 12

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

Question 13

What are Positive and Negative selection pressures?

Answer 13

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

Question 14

Three modes of selection are…

Answer 14

Stabilising, Direction and Disruptive.

Question 15

What is the Bottleneck Effect?

Answer 15

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

Question 16

What is the Founder Effect?

Answer 16

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 17

What is Genetic Isolation?

Answer 17

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

Question 18

What are the main mechanism of isolation?

Answer 18

• Spatial
• Reproductive
• Temporal
• Behavioural

Question 19

Prezygotic Isolating Mechanisms are…

Answer 19

Geographic. Temporal. Behavioural. Morphological.

Question 20

Postzygotic Isolating Mechanisms are…

Answer 20

Hybrid Inviability. Hybrid Sterility.

Question 21

What are the modes of speciation?

Answer 21

Allopatric. Sympatric. Parapatric.

Question 22

What is Allopatric Speciation?

Answer 22

Occurs when a geographical barrier divides a population.

Question 23

What is Parapatric Speciation?

Answer 23

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

Question 24

What is Sympatric Speciation?

Answer 24

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

Question 25

What are the 4 Diversification patterns?

Answer 25

• Divergent
• Convergent
• Parallel
• Coevolution

Question 26

What is Divergent Evolution?

Answer 26

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

Question 27

What is Convergent Evolution?

Answer 27

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