Genetic Info,Variation and relationships 2

Question 1

What decrease genetic diversity?

Answer 1

Genetic bottlenecks and the founder effect

Question 2

What is genetic diversity?

Answer 2

The number of different alleles of a gene present in a species of population.

Question 3

what increases a species chance of survival?

Answer 3

High genetic diversity

Question 4

What is a genetic bottleneck?

Answer 4

when there is a sharp reduction in the size of a population due to: environmental events, human activities, or a large number of individuals dying for producing. This reduces the number of alleles in the gene pool so when they reproduce the population increases, but there will be reduced genetic diversity.

Question 5

What is the founder effect?

Answer 5

When a small number of a population break away from the main population, and start a new colony, taking only a small number of alleles with them. New generations will only have these alleles.

Question 6

What is the gene locus?

Answer 6

Position of a gene on a chromosome

Question 7

How does natural selection occur?

Answer 7

Randomly occurring mutations sometimes result in advantageous allele is being formed.
Individuals without advantageous, allele, or more likely to survive reproduce and pass on their genes.
A greater proportion of the next generation inherit the allele, and they in turn survive, breed and pass it on.
This eventually leads to evolution as the advantageous allele is more common in the population.

Question 8

What are the types of adaptations?

Answer 8

Anatomical, behavioural, and physiological

Question 9

What does anatomical adaptions mean?

Answer 9

Structural features in an organisms body that increase chances of survival.

Question 10

what are behavioural adaption?

Answer 10

The way an organism acts to increase its chance of survival.

Question 11

What are physiological adaptions?

Answer 11

processes inside the body, which increase chances of survival.

Question 12

What are the different types of selection?

Answer 12

Directional, stabilising, disruptive

Question 13

What is directional selection?

Answer 13

Selection where individuals with alleles for characteristics at one extreme are favoured.

Question 14

When does directional selection take place?

Answer 14

when an environmental change takes place and put selection pressure on one of the extremes.

Question 15

What is stabilising selection?

Answer 15

where individuals with alleles for characteristics towards the middle range are favoured, thereby reducing the range of characteristics.

Question 16

When does stabilising selection take place?

Answer 16

When the environment is stable, and unchanging.

Question 17

What does stabilising selection tend to do?

Answer 17

Eliminate extreme variations from the population.

Question 18

What is an example of directional selection?

Answer 18

Bacteria can become resistant to antibiotics.

Question 19

What is an example of stabilising selection?

Answer 19

Babies born in a middle weight range are more likely to survive.