Cells

Question 1

What are the two types of cell division?

Answer 1

mitosis and meiosis

Question 2

What is created through mitosis?

Answer 2

2 genetically identical daughter cells, they have the same number of chromosomes as the parent cell

Question 3

What is created through meiosis?

Answer 3

4 genetically unique daughter cells, they each have half the number of chromosomes as the parent cell

Question 4

List the 3 stages of the cell cycle

Answer 4

Mitosis, Interphase: (G1, synthesis, G2), Cytokinesis

Question 5

What is interphase?

Answer 5

growth stages (most of the cell cycle) ie G1, synthesis, G2

Question 6

Describe what happens to a cell in interphase

Answer 6

DNA unravels + replicates, organelles replicate + ATP increases

Question 7

What is mitosis?

Answer 7

the formation of two new identical daughter cells from an original parent cell

Question 8

Why is mitosis necessary?

Answer 8

it replaces damaged or old cells and is how organisms grow and repair, it is a form of asexual reproduction

Question 9

What is cytokinesis?

Answer 9

final stage of mitosis where the 2 joined cells separate into 2 daughter cells

Question 10

What type of cells undergo mitosis?

Answer 10

body cells that are unspecialised or retain the ability to divide

Question 11

Describe 3 uses of mitosis by organisms

Answer 11

for growth and repair of human cells (e.g. skin), embryonic development, asexual reproduction of plants

Question 12

List the stages of mitosis in order

Answer 12

prophase, metaphase, anaphase, telophase

Question 13

What is a centromere?

Answer 13

the centre point of a chromosome- holds 2 sister chromatids together

Question 14

What is a centriole?

Answer 14

bundles of protein, which produce spindle fibres and move to poles of the cell in prophase

Question 15

Describe what occurs in prophase

Answer 15

nuclear envelope breaks down, centrioles move to either end, chromosomes condense

Question 16

Describe what occurs in metaphase

Answer 16

chromosomes line up on the spindle equator, spindle fibres attach to centromeres

Question 17

Describe what occurs in anaphase

Answer 17

no nuclear envelope, v-shaped chromatids being pulled apart to opposite ends of the cell

Question 18

Describe what occurs in telophase

Answer 18

chromatids uncoil and nuclear envelope reforms

Question 19

If 10 cells out of 100 are in metaphase and one cycle takes 15 hours, how long (in minutes) do the cells spend in metaphase?

Answer 19

15x60=900, (10/100)x900= 90 mins

Question 20

What causes cancer? (simplified)

Answer 20

when the cell cycle is out of contol (gene mutation)

Question 21

How are tumours linked to cell division?

Answer 21

tumours are caused by uncontrolled cell division

Question 22

What is the name given to the different types of tumour?

Answer 22

benign (non cancerous) and malignant (cancerous)

Question 23

What is the basic difference between a benign and a malignant tumour?

Answer 23

a benign tumour grows slowly and is kept in one place, not typically life threatening, a malignant tumour grows quickly and will spread around the body, more likely to be life threatening

Question 24

What affects the rate of cell division?

Answer 24

the environment, growth factors and 2 genes

Question 25

What happens if the genes controlling cell division are damaged (mutated)?

Answer 25

uncontrolled mitosis can occur

Question 26

If uncontrolled mitosis due to mutation occurs, how does this affect the cells being created?

Answer 26

they are usually structurally and functionally different to normal body cells, typically they die or are destroyed

Question 27

If the damaged cells that created the genetic mutation survive, what could happen?

Answer 27

the could clone themselves and form either benign or malignant tumours

Question 28

Vincristine is a cancer drug which prevents spindle fibres from forming, describe how this will treat the tumour

Answer 28

no spindle = no anaphase so mitosis cannot occur, cells can’t divide + cancer can’t develop further

Question 29

What are the inner folds of mitochondria called?

Answer 29

cristae

Question 30

what is the function of the golgi apparatus?

Answer 30

to process and package new proteins and lipids; makes lysosomes

Question 31

What is the function of a lysosome?

Answer 31

contains enzymes- lysozymes used to digest broken/ invaded cells (pathogens)

Question 32

What is the function of a ribosome?

Answer 32

protein synthesis