Mitosis

Question 1

What percentage of the dust in your home is made up of skin cells?

Answer 1

70%

Question 2

When do your skin cells replace themselves?

Answer 2

Every 20 days

Question 3

when do liver cells replace?

Answer 3

Every 200 days

Question 4

When do brain cells replace?

Answer 4

Every 30-50 days

Question 5

When do red blood cells replace?

Answer 5

Every 120 days

Question 6

When do stomach lining cells replace?

Answer 6

every 2 days

Question 7

When do intestinal lining cells replace?

Answer 7

Every 3 days

Question 8

What are the three stages of the cell cycle?

Answer 8

Interphase, mitosis and cytokinesis

Question 9

What is interphase?

Answer 9

• The stage where the cell carry out the functions necessary for survival and cells that divide prepare for reproduction
• The longest stage in the cell cycle

Question 10

What is mitosis?

Answer 10

• The stage where mitosis divides the duplicated contents of the cell’s nucleus into two equal parts
• The shortest stage in the cell cycle

Question 11

What is cytokinesis?

Answer 11

The stage where cytokinesis separates the two nuclei and cell contents into two daughter cells

Question 12

What happens in the first stage of interphase?

Answer 12

Growth and preparation: the cell increases to its full size and makes the proteins and molecules necessary for the cell to function. Some organelles begin to duplicate.

Question 13

What happens in the second stage of interphase?

Answer 13

Replication: When DNA makes a copy of itself by separating the two sides of the DNA with an enzyme. The new bases pair with the original two sides.

Question 14

What is the third stage of interphase?

Answer 14

Continued growth and preparation: The cell continues to grow and make proteins for the new cell made in cytokinesis (the daughter cell). Also, organelles are duplicated.

Question 15

What are the sister chromatids and centromere?

Answer 15

the sister chromatids are the two sides of the chromosome joined together by the centromere.

Question 16

What happens in the first stage of mitosis?

Answer 16

Early prophase:

• Replicated chromosomes coil into x-shaped chromosomes
• The nucleolus disappears and the nuclear membrane starts to break down
• Centrioles move to the opposite poles and spindle fibres attach to them

Question 17

What happens in the second stage of mitosis?

Answer 17

Late prophase:

• spindle fibres finish forming and attach to the centrioles
• nuclear membrane completely disappears.

Question 18

What happens in the third stage of mitosis?

Answer 18

Metaphase:

- The spindle fibres pull the chromosomes into a line in the middle of the equator

Question 19

What is the fourth stage of mitosis?

Answer 19

Anaphase:
- the spindle fibres shorten, which pulls the centromeres apart and sister chromatids move to opposite sides of the cell (the sister chromatids are now considered a chromosome)

Question 20

What is the fifth stage of mitosis?

Answer 20

Telophase:

• Spindle fibres disappear and the nuclear membrane forms around each set of chromosomes
• the nucleolus appears in both sets of chromosomes
• the cell is now ready to divide

Question 21

What is cytokinesis?

Answer 21

The final stage of the cell cycle which separates the two nuclei into two daughter cells.

Question 22

How does cytokinesis work in animal cells?

Answer 22

The cell membrane pinches together and separates the cytoplasm and organelles

Question 23

How does cytokinesis work in plant cells?

Answer 23

A cell plate forms in between the cells and separates them

Question 24

What are the three reasons why cells will not divide?

Answer 24

• There are not enough nutrients to support cell growth
• DNA within the nucleus has not been replicated
• DNA is damaged

Question 25

What is cancer?

Answer 25

a disease that causes cell division to be uncontrollable. Cells grow in multiple layers which form tumours.