Topic 2- stages of mitosis

Question 1

What happens to the chromosomes in prophase?

Answer 1

Condense

Question 2

When are the chromosomes visible when stained

Answer 2

In prophase

Question 3

What do chromosomes consist of?

Answer 3

Two identical chromatids- sister chromatids

Question 4

Where are the chromatids Joined together?

Answer 4

At the centromere

Question 5

What happebns to the nuclear envelope in prophase?

Answer 5

Breaks down into small vesicles

Question 6

Where do spindle fibres emerge from?

Answer 6

Centrosomes

Question 7

Describes what happens in prophase

Answer 7

-Chromosomes condense
-Chromatids join at the centromere
-Centrosomes move towards opposite poles

Question 8

Describe what happens in metaphase

Answer 8

-Centrosomes reach opposite poles
-Spindle fibres extend from centrosomes
-Chromosomes line up on the equator of the spindle/metaphase plate
-Spindle fibres attach to centromeres

Question 9

Describe what happens in anaphase

Answer 9

-Sister chromatids separate at the centromere
-Spindle fibres shorten
-Sister chromatids pulled to opposite poles

Question 10

Describe what happens in telophase

Answer 10

-Chromosomes decondense
-Nuclear envelopes reform
-Spindle fibres break down

Question 11

What is a centrosome

Answer 11

Two centrioles

Question 12

How do you calculate mitotic index?

Answer 12

mitotic index = number of cells with visible chromosomes ÷ total number of cells