2. Chromosome Mutations

Question 1

In humans, what happens when meiosis goes RIGHT?

Answer 1

All 4 daughter cells will end up with 23 whole chromosomes.

One from each homologous pair.

Question 2

In humans, What happens when meiosis goes WRONG?

Answer 2

Cells produced contain variations in number of whole chromosomes produced or parts of chromosomes.

Question 3

When is chromosomes mutation caused?

Answer 3

During errors made is meiosis.

Question 4

What negative things can chromosome mutation lead to?

Answer 4

Inherited conditions because the errors are present in gametes - hereditary cells.

Question 5

Name a type of chromosome mutation?

Answer 5

Chromosome non-dis junction.
Failure for chromosomes to separate properly.
Lead to down syndrome.

Question 6

How is downs syndrome caused?

Answer 6

Person having an extra copy/or part of chromosomes 21.

Question 7

What does non-disjunction of chromosome 21 mean?

Answer 7

Chromosome 21 fails to separate properly during meiosis, so one cell gets an extra copy of 21 and another gets none.

Question 8

What happens during fertilisation during chromosome non-disjunction?

Answer 8

When the gamete with the extra copy fuses to another gamete at fertilisation, the resulting zygote will have 3 copies of chromosome 21(downsyndrome).