10.5 Types Of Variation

Question 1

What are the two types of variation?

Answer 1

Genetic variation

Environmental variation

Question 2

What are six genetic causes of variation?

Answer 2

DNA mutation 
Crossing over
Independent assortment
Random fertilisation
Sexual reproduction
Alleles

Question 3

How is genetic variation introduced by DNA mutations?

Answer 3

The base sequence of the DNA is altered by mutation, producing new alleles

Question 4

How is genetic variation introduced by crossing over?

Answer 4

Non-sister chromatids genetic information during prophase 1 of meiosis creating new allele combinations

Question 5

How is genetic variation introduced by independent assortment?

Answer 5

The random alignment of homologous pairs in metaphase 1 and of sister chromatids in metaphase 2 creates new allele combinations in gametes

Question 6

How is genetic variation introduced by random fertilisation?

Answer 6

During sexual reproduction, the identity of the two gametes that combine to form a zygote is largely due to chance