Genetic Variation

Question 1

What does phenotype variation mean?

Answer 1

Differences in the observable characteristics among individuals of the same species

Question 2

How can phenotypic variation arise from?

Answer 2

Genetic factors
Environmental factors
Both genetic and environmental factors

Question 3

Genetic variation causing variation in phenotypes is due to?

Answer 3

Mutations
Meiosis
Random fertilisation of gametes
Environmental factors

Question 4

Genetic variation from sexual reproduction?

Answer 4

Crossing over of non-sister chromatids during prophase I of meiosis
Independent assortment of chromosomes during metaphase I of meiosis
Random fertilisation of gametes during fertilisation

Question 5

What is independent assortment of homologous chromosomes during metaphase I?

Answer 5

Random alignment of chromosomes results in different combinations of chromosomes and different allele combinations in each gamete

Question 6

Consequences of independent assortment?

Answer 6

Genetic variation between gametes produced by an individual

Question 7

Crossing over of non-sister chromatids during prophase I?

Answer 7

Exchange of genetic material between non-sister chromatids leads to new combinations of alleles on chromosomes
Can also break the linkage between genes

Question 8

Consequences of crossing over?

Answer 8

Genetic variation between GAMETES produced by an individual

Question 9

Random fertilisation of gametes during fertilisation?

Answer 9

Any male gamete can fuse with any female gamete (random mating in a species population)

Question 10

Consequence of random fertilisation?

Answer 10

Genetic variation between ZYGOTES and resulting individuals

Question 11

Mutation?

Answer 11

Random change in the DNA base sequence results in the generation of a new alllele

Question 12

Consequence of mutation?

Answer 12

genetic variation between INDIVIDUALS within a species population