Cell Division - Mitosis

Question 1

Where does the cell cycle start and end?

Answer 1

Mitosis

Question 2

What happens in gap phase 1?

Answer 2

Cell grows and new organelles and proteins are made

Question 3

What happens in the synthesis stage?

Answer 3

Cell replicates it’s DNA, ready to divide by mitosis.

Question 4

What happens in gap phase 2?

Answer 4

Cell keeps growing and proteins needed for cell division are made.

Question 5

Which stages of the cell cycle are in interphase?

Answer 5

Gap Phase 1
Synthesis
Gap Phase 2

Question 6

What happens during interphase?

Answer 6

Cell prepares to divide
Cell’s DNA unravelled and replicated to double genetic content
Organelles also replicated
ATP content increased

Question 7

What is produced via mitosis?

Answer 7

2 genetically identical daughter cells

Question 8

What is mitosis needed for?

Answer 8

Growth and repair

Question 9

What are the separate strands called in a chromosome?

Answer 9

Chromatids

Question 10

What joins these chromatids?

Answer 10

Centromere

Question 11

What are the 2 strands on the same chromosome called?

Answer 11

Sister chromatids

Question 12

What is the first stage of mitosis?

Answer 12

Prophase - chromosomes condense, centrioles move to opposite ends of cell forming the spindle, nuclear envelope breaks down, chromosomes free in cytoplasm

Question 13

What is the second stage in mitosis?

Answer 13

Metaphase - chromosomes line up in the middle of the cell and attach to spindle by centromere

Question 14

What is the third stage of mitosis?

Answer 14

Anaphase - centromeres divide, sister chromatids separate, pulls chromatids to opposite poles of spindle, chromatids appear v-shaped

Question 15

What is the fourth stage of mitosis?

Answer 15

Telophase - chromatids reach opposite poles on spindle, chromosomes again, nuclear envelope reforms, cytokinesis, 2 daughter cells

Question 16

Which areas of the cell cycle do cancer treatments target?

Answer 16

G1 (cell growth and protein production)

s phase (DNA replication)

Question 17

How do you prepare a root tip cell squash?

Answer 17

1. Add 1 M HCl to boiling tube. Enough to cover root tip. Put tube in water bath at 60 °C
2. Cut 1cm from tip of root (where mitosis takes place)
3. Transfer root to boiling tube and incubate for 5 mins.
4. Remove root and rinse. Leave tip to dry.
5. Place on slide, cut 2mm from tip.
6. Break tip open and spread cells out thinly.
7. Add stain
8. Cover slip and squash.
9. Look under microscope

Question 18

How do you use an optical microscope?

Answer 18

1. Clip slide to stage.
2. Choose lowest powered objective lens.
3. Use coarse adjustment knob to bring stage below lens.
4. Look down eye piece. Use CAK to move stage down until in focus.
5. Adjust with FAK
6. Swap to higher powered objective lens.

Question 19

How do you calculate mitotic index?

Answer 19

Number or cells with visible chromosomes/ total number of cells observed

Question 20

How do you calculate the actual size of cells?

Answer 20

1. Line up eyepiece graticule with stage micrometer
2. Work out the value of divisions on the eyepiece graticule at a particular magnification.
3. Take stage micrometer away and replace with slide to measure size of cells.