Topic 4 - Genetic Diversity & Natural Selection [7]

Question 1

Evolution

Answer 1

the change in allele frequency over many generations in a population.

Question 2

Stabilising Selection

Answer 2

NO change in environment
those with the ‘modal trait’ have the selective advantage
trait stays the same
standard deviation decreases cuz individuals with the extreme trait decrease

Example human birth weights
if baby light more likely to have underdeveloped organs, u gonna die
if baby heavy complications in child birth, u gonna die.

the modal trait of normal weight 6-9 pounds is favoured since the dawn of time so it is the normal.

Question 3

Directional Selection

Answer 3

ONE of the extremes has the selective advantage
Occurs when there’s a change in the environment
e.g. antibiotic resistance in bacteria

(og environment no antibiotics, new environment antibiotics so bacteria dying but those with resistance are the selective advantage. they survive and reperoduce and pass that shit on)

Over many generations, we see a shift and more bacteria have that resistance. makes the extreme.

Question 4

Describe the Process of Natural Selection

Answer 4

New alleles for a gene are created by random mutations
e.g. black fur for mice

if the new alleles increase chances of survival (in that environment) they are more likely to survive and reproduce.
e.g. black mice less hunted cuz harder to see so survive and reproduce.

This reproduction passes on the beneficial allele to next generation.
mice kids are BLACK

Over many generations, the new allele has higher frequency.
BLACK MICE EVERYWEHRE

Question 5

In Natural Selection. Adaptations can be Anatomical, Physiological or even Behavioural.
True or False?

Answer 5

True. Even a change in behaviour like penguins huddling together in the cold is considered an adaptation

Physiological - refers to chemical reactions in the body

Question 6

Natural Selection

Answer 6

the process that leads to evolution in populations.

It results in species becoming better adapted to their environment.

Question 7

Genetic Diversity

Answer 7

is the number of different alleles of genes in a population.

Question 8

Evolution

Answer 8

the change in allele frequency over many generations in a population.