Genetic Diversity/ Natural Selection

Question 1

What is genetic diversity?

Answer 1

• Genetic diversity is the number of different alleles of genes in a
  population.

Question 2

True or False

A species of foxes are all the exact same with the exact same genes. Over time, the foxes will change so they are more adpated to their environment.

Answer 2

• False!!
• There must be genetic diversity in a population for natural selection to occur.

Question 3

What is natural selection? What does it result in?

Answer 3

• Natural selection = process that leads to evolution in populations.
• Results in species that are better adapted for their environment.

Question 4

What are the 3 different types of adaptations?

Answer 4

1.) Anatomical (structure of organism.)
2.) Physiological (chemical reactions.)
3.) Behavioural

() - extra info for clarification.

Question 5

What is “evolution?”

Answer 5

• Evolution is the change in allele frequency over many generations in a population.

Question 6

Give the stages of natural selection that leads to evolution.

Answer 6

1.) Random mutations can result in new alleles of a gene.
2.) If new allele of gene increases chance of survival in specific environment, the organism with the alllele is more likely to survive and reproduce.
3.) The advantageous allele is inherited by members of the next generation.
4.) As a result, over many generations, the new allele increases in frequency in the population.

Question 7

True or False

MANY mutations - creating new alleles of a gene - allow the possesor of new allele to be more adapted to their environment.

Answer 7

• False.
• Many mutations are harmul (only a few actually lead to posessor of new allele being more adpated to their environment.)

()- extra info for clarification.

Question 8

What are the two different types of natural selection?

Answer 8

1.) Directional selection.
2.) Stabilising selection.

Question 9

What is directional selection? Give an example.

Answer 9

• Directional selection.
• One one of the extremes - bacteria that have high antibitoic resistance - has the selective advantage.
• This will only occur when there is a change in the environment - ie in environment of antibitioics -
• The modal trait changes - no of bacteria with high antibiotic resistance increases -
• Example: antibitoic resistance in bacteria.

()- extra info for clarification.

Question 10

What is stabilising selection? Give an example.

Answer 10

• Modal trait has selective advantage
• Occurs when there is no change in environment.
• Modal trait remains the same
• Standard deviation (in traits/ alleles) decreases, as individuals with the extreme traits decrease.
• Example: human birth weights (humans born with average birth weight have selective advantage over those born with the 2 extremes.)

()- extra info for clarification.