Mistakes

Question 1

Name the stage of the cell cycle that is in greater number than the others and explain this observation

Answer 1

Interphase

This is the longest phase

Question 2

State the purpose of meiosis

Answer 2

Produce gametes for genetic variation

Question 3

Name the organs in animals where meiosis occurs

Answer 3

Ovaries

Question 4

Label X and Y

Answer 4

X centriole

Y spindle

Question 5

Name the process represented in this diagram

Answer 5

Cytokinesis

Question 6

Explain the importance of meiosis in an animal

Answer 6

Produces genetically different gametes which contribute to genetic variation
Produces haploid cells so that 2 gametes will restore the diploid number

Question 7

The cells labelled C are in interphase. Explain why nuclei are only visible in some cells and, where nuclei are visible, why they appear to be of different sizes.

Answer 7

• plane of the section of the cell may not contain a nucleus

* the nucleus may have been cut at different levels

Question 8

Describe the changes that occur to a plant cell during prophase.

Answer 8

• nucleus and nuclear membrane disintegrates
• chromatin condenses so chromatids can be seen in pairs joined at the centromere
• centrioles move to the poles
• spindle form

Question 9

Meiosis produces four daughter cells, whereas mitosis only produces two daughter cells.
Describe two other ways in which the cells produced by meiosis would differ from those produced by mitosis.

Answer 9

• meiosis - genetically different to eachother and parent cells
• mitosis - genetically identical
• meiosis - haploid cells
• mitosis diploid cells

Question 10

Describe and explain what happens to chromosomes during anaphase of mitosis.

Answer 10

• spindles shorten which pulls chromatids to separate poles

* centromere splits

Question 11

State three ways in which meiosis contributes to variation

Answer 11

• crossing over
• independent assortment
• haploid cells produced

Question 12

State events that occur during interphase

Answer 12

• DNA replication
• making new organelles
• protein synthesis

Question 13

Explain how mitosis maintains genetic stability

Answer 13

• produces 2 genetically identical cells to the parent cell

Question 14

How are cellulose and chitin similar structural polysaccharides

Answer 14

Adjacent monomers twisted through 180• to each other, allowing hydrogen bonds between chains, forming microfibrils