Cell Division

Question 1

What is mitosis used for?

Answer 1

Growth
Repair
Asexual reproduction

Question 2

What is meiosis used for?

Answer 2

Gamete production

Genetic variation

Question 3

What does mitosis produce?

Answer 3

Two genetically identical diploid daughter cells

Question 4

What does meiosis produce?

Answer 4

Four genetically unique haploid daughter cells

Question 5

What does diploid mean?

Answer 5

Two copies of each chromosome

Question 6

What does haploid mean?

Answer 6

One copy of each chromosome

Question 7

How many chromosomes do humans have?

Answer 7

46 (23 pairs)

Question 8

What sex chromosomes do males have?

Answer 8

XY

Question 9

What sex chromosomes do females have?

Answer 9

XX

Question 10

What is a pair of chromosomes called?

Answer 10

Homologous pair

Question 11

What is the name of the stage in mitosis when the cell is not dividing?

Answer 11

Interphase

Question 12

What are the four stages of mitosis?

Answer 12

Prophase
Metaphase
Anaphase
Telophase

Question 13

What is the division of cytoplasm called?

Answer 13

Cytokinesis

Question 14

What happens at interphase?

Answer 14

DNA replicates
Organelles replicate
Centrioles replicate
Chromatin is uncoiled

Question 15

What holds the homologous chromosomes together?

Answer 15

The centromere

Question 16

What happens in prophase of mitosis?

Answer 16

Chromatin condenses to form chromosomes
Nuclear envelope breaks down
Replicated centrioles move to opposite poles
Spindle fibres (tubulin) begin to form at poles

Question 17

What forms around the centromere and attaches to the spindle fibres during mitosis?

Answer 17

A protein complex called the kinetochore

Question 18

What happens during metaphase of mitosis?

Answer 18

Kinetochores attach to spindle microtubules

Chromosomes line up along the equator

Question 19

What happens in anaphase of mitosis?

Answer 19

Sister chromatids are pulled apart and now called chromosomes
Chromosomes move towards opposite poles of the cell

Question 20

What makes the chromosomes move the opposite poles during anaphase?

Answer 20

The microtubules shortening my removing tubulin subunits, called depolymerising

Question 21

What happens in telophase of mitosis?

Answer 21

Chromosomes have reached the poles and begin to decondense so nucleolus reforms
Nuclear envelope forms around chromosomes at each pole
Spindle breaks down

Question 22

Process of cytokinesis in animal cells?

Answer 22

The cell membrane pinches in the middle to form a cleavage furrow
The cytoskeleton (microfilaments) then continues to pull the membrane inwards

Question 23

Process of cytokinesis in plant cells?

Answer 23

Cannot form cleave furrow due to cell wall
Golgi vesicles contain components needed for a new cell wall assemble across the equator (cell plate) and fuse to make a new membrane
New cell walls form on either side of the membrane

Question 24

Where does meiosis take place in humans?

Answer 24

Ovaries or testes

Question 25

Why do gametes have half the normal chromosome number?

Answer 25

To fuse with another gamete to produce a zygote with the normal number of chromosomes

Question 26

How many times does the cell divide in mitosis?

Answer 26

Once

Question 27

How many times does the cell divide in meiosis?

Answer 27

Twice

Question 28

What addition processes happen in prophase 1 of meiosis compare to mitosis?

Answer 28

Members of homologous pairs find each other and lie close together (process called synapsis) Non-sister chromatids become so close that they can overlap (called chiasmata) this can lead to crossing over of genetic material

Question 29

What is different about metaphase 1 of meiosis compare to mitosis?

Answer 29

The chromosomes line up along the equator in homologous pairs

Question 30

How does genetic variation happen through meiosis? (4)

Answer 30

Chiasmata and crossing over of genetic information Which random arrangement of maternal/paternal chromosomes called independent assortment in metaphase 1 Orientation of each chromosome in metaphase 2 Random fusion of the gametes produced by meiosis

Question 31

How is anaphase 1 in meiosis different to mitosis?

Answer 31

Sister chromatids are not separated as there is no division of the centromere