Cell Division

Question 1

What is most DNA

Answer 1

Thread like called chromatin

Question 2

Define diploid cells

Answer 2

A cell with 2 sets of chromosomes (2n)

All body cell are diploid except sex cells

Question 3

Define Haploid Cells

Answer 3

Sex cells have only 23 chromosomes only come from one parent (n)

Question 4

What happens during a cells lifecycle

Answer 4

Cells split into interphase and dividing phase

DNA forms chromosomes

DNA replicates

Question 5

Define Interphase

Answer 5

When cells builds up chemicals and grows bigger. In this phase for 90% of its life

Question 6

Define Mitosis and name its stages

Answer 6

Mitosis is a form of nuclear division in which one nucleus divides to form 2 nuclei, each containing identical sets of chromosomes

Prophase
Metaphase
Anaphase
Telophase

Question 7

Describe Prophase

Answer 7

Chromosomes are double stranded
Spindle fibres start moving to the poles
Membrane of nucleus breaks down

Question 8

Describe Metaphase

Answer 8

Chromosomes line up in the middle of the cell
Spindle fibres attach to the chromosomes
The membrane of the nucleus is broken down

Question 9

Describe Anaphase

Answer 9

Spindle fibres contract
Chromosomes are pulled apart
Chromosomes move towards the poles

Question 10

Describe Telophase

Answer 10

Chromosomes change back into chromatin

The membrane of the nucleus is reformed

Question 11

Define Cytokinesis

Answer 11

The splitting of the two new cells

Question 12

What are the functions of mitosis in Unicellular organisms

Answer 12

Makes 2 new organisms (Asexual reproduction)

Question 13

What are the functions of mitosis in multicellular organisms

Answer 13

Allows organism to grow larger

Repairs damaged cells

Question 14

Define Cancer and name the 2 types

Answer 14

A group of disorders in which certain cells lose their ability to control the rate of mitosis and number of times it happens

Benign
Malignant

Question 15

Describe Benign and Malignant Cancer

Answer 15

Benign: Type of cancer that stops dividing after a certain amount of time e.g warts or skin tags

Malignant: Tumours caused by genes that have been changed, changes caused by carcinogens e.g cigarette smoke or radiation

Question 16

How is cancer treated

Answer 16

Treatments include surgery, radiation and chemicals (chemotherapy)

Question 17

Describe Meoisis and what it allows for

Answer 17

Form of nuclear division in which 4 daughter cells contain half the number of parent chromosomes

Meoisis makes sex cells and allows for variation and sexual reproduction

Question 18

Describe the process of cell division in animals

Answer 18

Occurs after mitosis
A shallow groove called a cleavage furrow forms
Keeps getting deeper until it divides in two (cytokinesis)
New cells are called daughter cells

Question 19

Describe the process of cell division in plant cells

Answer 19

A line of bubbles (vesicles) form down the centre
Vesicles contains cellulose (structural polysaccharide) which forms a new cell wall
The cell divides in 2

Question 20

Draw a diagram of Prophase, Metaphase, Anaphase and Telophase

Answer 20