Variation and inheritance

Question 1

What is variation?

Answer 1

Changes in genetic code
–> random + constantly taking place

Essential for natural selection

Question 2

Define chlorosis:

Answer 2

Where leaves look pale/yellow (etiolation)

Cells not producing normal amount of chlorophyll

Reduces photosynthesis

Question 3

What environmental factors impact chlorosis?

Answer 3

Lack of light: absence of light = conserve resources

Mineral deficiencies:
->Fe = cofactor to enzymes,
leaves become yellow

Virus infection: Interfere with metabolism –> infect tissues

Question 4

How do environmental factors impact body mass?

Answer 4

Quality/quantity of food consumed

Presence of disease

Amount of exercise

Question 5

How to genetic factors impact body mass?

Answer 5

Mutation of Chromosome 7.

Pattern of fat deposition in body to be altered.
–> Gene acts as conjunction with other genes that regulate energy balance of the body.

Question 6

How is genetic variation made?

Answer 6

~Number of different possible allele combinations from parents (crossing over, independent assortment)

~Mixture of alleles inherited influences displayed characteristics

~Random fusion of gametes at fertilisation

Question 7

Define genotype:

Answer 7

Combination of alleles an organism inherits for a characteristic

Question 8

Define phenotype:

Answer 8

Observable characteristics of an organism.

Question 9

What is the difference between modification + mutation?

Answer 9

Changes to phenotype by environment = not inherited (modification)

Question 9

Describe continuous variation:

Answer 9

A characteristic that can take any value within a range.

Can be genetic/environmental

Controlled by number of genes (polygenic)

e.g: animal mass