Genetic Variation - chuck test 1

Question 1

Chiasma

Answer 1

The point in which paired chromosomes contact during crossing over

Question 2

Crossing over

Answer 2

Two homologous chromosomes pair up, creating a homologous pair of chromosomes. The non-sister chromatids swap alleles. Resulting in new combinations of alleles, meaning there is genetic variation.

Question 3

Diploid Cell

Answer 3

A cell that contains a complete set of chromosomes (e.g in humans 46 chromosomes)

Question 4

Haploid Cell

Answer 4

A cell that contains half as many chromosomes as a diploid cell (e.g in humans 23 chromosomes)

Question 5

Gamete

Answer 5

A reproductive cell having haploid number of chromosomes (e.g in females egg and males sperm)

Question 6

Independent Assortment

Answer 6

when homologous chromosomes line up in the equator (centre) of the cell, independently of other pairs. Resulting in a randomised line. They are then separated in segreation which resultings in genetic variation as each gamaete receives one chromosomes, meaning there will be different allees in each gamete.

Question 7

locus

Answer 7

a location a given gene occupies on a chromosome

Question 8

Meiosis

Answer 8

A type of cell division in sexually reproducing organisms that process gametes and reduces the number of chromosomes in the reproductive cells from diploid to haploid.

Question 9

Segregation

Answer 9

The separation of paired alleles of (pairs of) homologous chromosomes. Resulting in each gamete receiving one allele or chromosome.

Question 10

Mutation

Answer 10

A permanent change to the base sequence of DNA - which may result in a new allele. This causes genetic variation as if the mutation occurs in a gamete it may be passed on to offspring if the gamete is fertilised.

Question 11

Mutagen

Answer 11

An agent that can create a mutation e.g chemicals, radiation etc