Chromosome structure, homologous chromosomes, + karyotypes

Question 1

What happens to chromosome structure during cell division?

Answer 1

Chromosomes condense - they become shorter + fatter, making them now visible under microscope

Question 2

What are histones?

Answer 2

Positively charged proteins

Question 3

How are histones involved in chromosome structure?

Answer 3

The DNA is wrapped around histones to help organise the DNA

Question 4

What are nucleosomes?

Answer 4

Structure of DNA wrapped around histone protein

Question 5

Explain what supercoiled is:

Answer 5

Coiled DNA strand is coiled again to form dense structures seen during cell division

Question 6

What are the roles of a centromere?

Answer 6

1. Join 2 chromatids together
2. Help moves chromatids as a pair
3. Allow for even segregation

Question 7

What happens to chromosomes during cell cycle?

Answer 7

Each chromosome duplicates so theres 2 copies. Each copy now called a chromatid

Copies temporarily held together to help with organisation during cell division

Question 8

What is a centromere?

Answer 8

The point at which copies of chromosomes are held together

Question 9

What are homologous chromosomes?

Answer 9

Matching pairs of chromosomes

Question 10

How can scientists match pairs of chromosomes together?

Answer 10

By staining the cell + making chromosomes visible

Question 11

What happens once the pairs of chromosomes are matched together?

Answer 11

Creates profile called a karyotype - Can be used in diagnosing genetic disorders