Meiosis and Genetic Variation

Question 1

What occurs in the first prophase of meiosis?

Answer 1

1.chromosomes condense and become visible as chromatids
2.they align in homologus pairs and crossing over occurs

Question 1

What is meiosis?

Answer 1

A type of cell division that produces four genetically different daughter cells
(gametes) with a haploid number of chromosomes. It involves two divisions

Question 2

What occurs in the first metaphase of meiosis?

Answer 2

1. homologus pairs line up at equator #
2. crossing over occurs
3. spindle fibres attach to centromeres

Question 3

What occurs in the first anaphase of meiosis?

Answer 3

1. spindles contract and pull apart homologus pairs to opposite poles
2. independent asstment occurs

Question 4

What occurs in the first telaphase of meiosis?

Answer 4

two new haploid nuclei have been made that aren’t clones

Question 5

What occurs in the second metaphase of meiosis?

Answer 5

chromosome re-align at the equator in a line of symetry

Question 6

What occurs in the second anaphase of meiosis?

Answer 6

spindles re-form and attach to centromere and pull the chromatids to the poles of the nucleus

Question 7

What occurs in the second telaphase of meiosis?

Answer 7

four cells that are genetically varied are produced (diploid cells)

Question 8

What is crossing over?

Answer 8

1. it’s when homologus chromosomes line up and their chromatids intertwine
2. they then exchange genetic material with each other

Question 9

How does crossing over create genetic varience?

Answer 9

it means that each homologus pair has a mixture of genetic material/ a combination of different alleles in the gene

Question 10

What is independent assortment/ seggregation (and how it creates variation)?

Answer 10

when the homologus pairs line up at the equator the arragement is random which means when they are pulled apart (by spindles) the way they are divided into the daughter cells is also random. This creates vatriation