B14- Variation and evolution

Question 1

Variation

Answer 1

Differences that exist within a species and between different species

Question 2

Genetic variation
Def?
Examples?

Answer 2

Characteristics inherited through parents’ genes
Eye colour, sex, blood type

Question 3

Environmental variation
Def?
Examples?

Answer 3

Characteristics influenced by the environment
Scars, tattoos, piercings

Question 4

3 examples of characteristics that are inherited, environmental and both?

Answer 4

Inherited- eye colour, sex, blood type
Environmental- tattoos, scars, accent
Both- height, hair colour, weight

Question 5

How is variation caused by mutations?
Are mutations planned?

Answer 5

Mutations in gamete formation can affect the phenotype of offspring
-Mutations are random, usually have little effect on an organism. Very rarely it makes the organism better suited to its environment.

Question 6

Theory of evolution
Who?
What?
How long ago?

Answer 6

Charles Darwin
All species of living things have evolved from simple life forms from 3 billions years ago

Question 7

Natural selection process? (3 steps)

Answer 7

-Variation exists within a population, causing different phenotypes
-Organisms that happen to be most suited to the environment are more likely to survive and breed successfully
-Their alleles are passed on the future offspring

Question 8

How to tell if a new species has been formed?

Answer 8

When the species can no longer breed to produce fertile offspring

Question 9

Selective breeding

Answer 9

When humans breed plants and animals for desired characteristics