Cell Division

Question 1

What is the process before cell division?

Answer 1

Semi-conservative DNA replication

Question 2

What does semi-conservative mean?

Answer 2

Each new DNA molecule contains one original strand from parent DNA and one new strand.

Question 3

Why is it important for DNA to have a double helix?

Answer 3

So it can act as its own template through universal complementary base pairing when replication DNA.

Question 4

How does DNA replication work?

Answer 4

Free-floating complementary nucleotides attach to each half of the exposed bases to synthesis new strands.

Question 5

What does cell division enable?

Answer 5

Growth, Repair, Reproduction, transfer of genetic material

Question 6

How do prokaryotes reproduce?

Answer 6

Through binary fission.

Question 7

What triggers binary fission?

Answer 7

As the bacterial cell increases in size, the cell continues to grow and split into two daughter cells.

Question 8

What is the process of binary fission?

Answer 8

Parent cell DNA is copied to form two identical coils of chromosomes through DNA replication.
The replicated chromosomes (two circular loops) attach to the cell membrane by proteins.
As the cell membrane grows, the loops are separated and pulled towards opposite directions.
A cleavage furrow forms and the cell membrane of the parent cell pinches inwards, forming two cells.
New cell wall is formed around each cell.
Two genetically identical daughter cells are formed, each with one circular chromosome.

Question 9

What are two copies of chromosomes called?

Answer 9

Sister chromatids

Question 10

What shape do sister chromatids look like?

Answer 10

An X

Question 11

How many pairs of chromosomes in human cells?

Answer 11

23

Question 12

What is a diploid cell?

Answer 12

When both members of a homologous pair are present (one from maternal, one paternal)

Question 13

What is a haploid cell?

Answer 13

If it only contains one set of chromosomes.

Question 14

What are the phases of mitosis?

Answer 14

Prophase, Metaphase, Anaphase, Telophase

Question 15

What happens during interphase?

Answer 15

Parent cell replicates DNA and increases in size.

Question 16

How do eukaryotic cells divide?

Answer 16

Mitosis

Question 17

State what happens in prophase.

Answer 17

The nuclear membrane breaks down and the nucleolus disappears. DNA condenses, chromosomes join with sister chromatids. Spindle fibres are assembled and move to the cell’s poles.

Question 18

State what occurs in metaphase.

Answer 18

All the chromosomes line up the middle of the cell and attach to spindle fibres.

Question 19

State what occurs in anaphase.

Answer 19

Sister chromatids are separated by the retracting of spindle fibres and move towards the poles (opposite directions)

Question 20

What occurs in telophase?

Answer 20

Spindle fibres break down and the chromosomes decondensed into chromatin, cell elongates

Question 21

What occurs in cytokinesis?

Answer 21

Cell membrane pinches inwards and two identical daughter cells are formed.

Question 22

What do binary fission and mitosis have in common?

Answer 22

Both are asexual reproduction, both used for growth and reproduction, both result in two genetically identical daughter cells, chromosomes are repeated after DNA replication

Question 23

What are some differences between mitosis and binary fission?

Answer 23

BF is one process, mitosis have two (mitosis and cytokinesis), chromosome attach to cell membrane in BF, spindle fibres separates in mitosis

Question 24

What is a mutagen?

Answer 24

Chemical or physical factors that increase chances of developing cancer and tumours

Question 25

Provide some examples of mutagens

Answer 25

UV rays, carcinogens