Biosphere- Biodiversity

Question 1

What is biodiversity

Answer 1

The totality of all genes, species and ecosystems in one location

Question 2

What is genetic drift

Answer 2

The change in frequency of a gene variant (allele) in a population due to random sampling

Question 3

Does genetic drift cause adaptation

Answer 3

NO! It may cause gene variants to disappear completely and thus reduce genetic variation. Does not produce adaptation

Question 4

Who first proposed the idea of natural selection

Answer 4

Charles Darwin in the Origin of Species

Question 5

What is speciation

Answer 5

Is the evolutionary process by which reproductively isolated biological populations evolve to become distinct species

Question 6

What is required for speciation

Answer 6

Genetic changes

Question 7

Allopatric speciation involves

Answer 7

PHYSICAL SEPARATION

Question 8

Example of allopatric speciation

Answer 8

Continental drift: cannot mix because they are in 2 different physical locations

Question 9

Peripatric speciation involves

Answer 9

Physical separation

Question 10

Explain peripatric speciation

Answer 10

Jump dispersal eg an isolated island. Small population means genetic drift occurs. New environment = natural selection and rapid divergence to fit into and survive in new environment

Question 11

Parapatric speciation involves

Answer 11

Non physical separation, no barrier

Question 12

What causes parapatric speciation

Answer 12

Environmental gradient eg pH in soil means there is a gradient of conditions. Some organisms would be more adapted to certain conditions so reproduce with others that are adapted to the same conditions so speciation occurs over time in the same area

Question 13

Sympatric speciation involves

Answer 13

Speciation occurring in the same population with no geographical barrier

Question 14

Example of sympatric speciation

Answer 14

Maggot flies

Question 15

What is disruptive selection?

Answer 15

Selection against the average

Question 16

What is vicariance (links to geographical isolation)

Answer 16

The separation of a group of organisms by a geographical barrier, resulting in differentiation of the original group into new varieties or species

Question 17

Vicariance events lead to what type of speciation

Answer 17

Allopatric

Question 18

What is redundancy in relation to species

Answer 18

More than one species performing a similar role in the ecosystem. If a species is removed and the ecosystem remains constant, it was redundant (walker)

Question 19

Why is biodiversity important in relation to global change

Answer 19

May be important in controlling how ecosystems respond to global change