Cell division

Question 1

Where are all cells derived from?

Answer 1

Pre existing cells

Question 2

What are new cells produced for?

Answer 2

For growth and to replace damaged or old cells

Question 3

What must happen to DNA before cell division?

Answer 3

Must be copied or replicated, so that each new cell will have an identical copy of the DNA

Question 4

What form is the DNA of prokaryotes (bacteria) ?

Answer 4

One circular chromosome attached to the inside of the cell membrane

Question 5

How do eukaryotic cells store genetic information?

Answer 5

In Chromosomes

Question 6

How many chromosomes do eukaryotes have in their body cells?

Answer 6

Between 10-50

Question 7

How many chromosomes do humans have?

Answer 7

46 or 23 identical pairs

Question 8

What form are eukaryotic chromosomes in?

Answer 8

Each chromosome is composed of a single tightly coiled DNA molecule. Chromosomes can’t be seen when cells aren’t dividing and are called chromatin

Question 9

How is DNA compacted into chromosomes?

Answer 9

DNA is tightly coiled around proteins called histones

Question 10

What are chromosomes in dividing cells called?

Answer 10

Duplicated chromosomes are called chromatids and are held together by the centromere.

Question 11

What are the first 22 pairs of chromosomes called?

Answer 11

Autosomes

Question 12

What are the last pair of chromosomes?

Answer 12

The last pair are sex chromosomes, XX female and XY male

Question 13

What does asexual reproduction involve?

Answer 13

One single cell dividing to make 2 new identical daughter cells. ( examples are mitosis and binary fission)

Question 14

What does sexual reproduction involve?

Answer 14

Two cells (egg and sperm) joining to make a new cell (zygote) that is not identical to the original cells. Meiosis is an example

Question 15

Cell division in prokaryotes?

Answer 15

• Prokaryotes such as bacteria divide into two identical cells by the process of binary fission.
• Single chromosome makes a copy of itself
• Cell wall forms between the chromosomes dividing the cell

Question 16

What is G1 in the Cell cycle?

Answer 16

Primary growth phase

Question 17

What is S in the cell cycle?

Answer 17

Synthesis- DNA replication

Question 18

What is G2 in the cell cycle?

Answer 18

Secondary growth phase

Question 19

What is interphase in the cell cycle?

Answer 19

G1, S, and G2

Question 20

What is M in the cell cycle?

Answer 20

Mitosis

Question 21

What is C in the cell cycle?

Answer 21

cytokinesis

Question 22

What order do the five phases of the cell cycle happen?

Answer 22

G1, S, G2, M, and C

Question 23

What happens in G1?

Answer 23

The first growth stage after cell division. Cells mature by making more cytoplasm and organelles.The cell carries on its normal metabolic activities during this stage

Question 24

What happens in S in the cell cycle?

Answer 24

Synthesis stage, DNA is copied or replicated two produce two identical copies

Question 25

What happens in G2 in the cell cycle?

Answer 25

The second growth stage, occurs after DNA has been copied. All cell structures needed for cell division are made (eg centrioles). Both organelles and proteins are synthesised

Question 26

What happens in interphase in the cell cycle?

Answer 26

DNA replicates, centrioles if present replicate, cell prepares for division

Question 27

What happens in Mitosis?

Answer 27

- Division of the nucleus - Also called karyokinesis - Only occurs in eukaryotes - Has four stages - Doesn’t occur in some cells such as brain cells