Cell Division

Question 1

Independent Assortment

2 marks

Answer 1

Process that takes place during meiosis, in which chromosomes are reassorted.



Question 2

In order to grow - most living organisms

2 marks

Answer 2

Increase their cell number - Cells double in number by splitting in half.

Question 3

2 types of cell division

2 marks

Answer 3

Mitosis + Meiosis

Question 4

Mitosis -
Explained

(5 marks)

Answer 4

Used to grow/replace worn out cells + repair damaged tissue.

• produces 2 new (daughter) Cells in 1 division.

Question 5

Number of Cells produced in Mitosis

2 marks

Answer 5

2 new cells (daughter cells) in 1 division.

Question 6

Cells produces during Mitosis

3 marks

Answer 6

Daughter cells - genetically identical (clones) to parent cell + each other.

Question 7

What does Mitosis ensure

3 marks

Answer 7

Every cell in the growing organism contains the same genes + chromosomes.

Question 8

Human sex cells contain:
-Meiosis-

(2 marks)

Answer 8

1 chromosome from each of the 23 pairs.

Question 9

Meiosis -
Explained

(5 marks)

Answer 9

Occurs in testes + ovaries

1 diploid cell produces 4 haploid gametes, in 2 divisions - this is reduction division.

Question 10

Meiosis -
Simplified

(3 marks)

Answer 10

1 diploid cell produces 4 haploid gametes, in 2 divisions

Question 11

Where does Meiosis take place?

2 marks

Answer 11

Testes + Ovaries

Question 12

Produced during Meiosis

4 marks

Answer 12

Haploid Gametes -

Sex Cells such as sperm/ovum with half the number of Chromosomes.

Question 13

Haploid conditions:
In detail

(3 marks)

Answer 13

1 copy of each Chromosome; non-homologous Chromosomes.

Question 14

Diploid conditions:
In detail

(3 marks)

Answer 14

2 copies of each chromosome; pairs of homologous Chromosomes (of maternal + paternal origin).

Question 15

Haploid gametes

2 marks

Answer 15

Human sex cells - contain 1 chromosome from each of the 23 pairs.

Question 16

4 gametes produced in meiosis are

3 marks

Answer 16

Genetically different - process of independent assortment leads to all gametes being different.

Question 17

Independent assortment + the random nature of fertilisation lead to

(3 marks)

Answer 17

Variation in living organisms – no 2 organisms are the same (apart from identical twins).

Question 18

Variation in living organisms

2 marks

Answer 18

No 2 organisms are the same (apart from identical twins).

Question 19

During fertilisation the Haploid Nucleus of a Sperm Cell + the Haploid Nucleus of an Egg Cell

(2 marks)

Answer 19

Fuse together to form a Diploid Zygote.

Question 20

Diploid Zygote

5 marks

Answer 20

Fusion of Sperm cells Haploid Nucleus + Egg cells Haploid Nucleus in a fertilised ovum (Zygote)

• 2 weeks after fertilisation becomes an Embryo with the full number of Chromosomes (23 pairs)

Question 21

Fertilised ovum

1 mark

Answer 21

Zygote

Question 22

After Cell division a fertilised ovum (zygote) develops into a

(1 mark)

Answer 22

Embryo

Question 23

Diploid Zygote becomes a
- the Next stage-

(1 mark)

Answer 23

Embryo

Question 24

Number of Chromosomes passed down from each parent during Fertilisation/Cell Division

(3 marks)

Answer 24

23 from Mother
23 from Father

= 46 Chromosomes

Question 25

Number of Chromosomes passed down from each parent during Fertilisation/Cell Division when the child has Down Syndrome (3 marks)

Answer 25

23 from one parent + 24 from the other | = 47 Chromosomes

Question 26

The Sperm Cell carries __ Chromosomes to the Ovum during Fertilisation (typically) (1 mark)

Answer 26

23

Question 27

The Ovum carries 23 ___________ (typically) | 1 mark

Answer 27

Chromosomes

Question 28

Stages of Mitosis (in order) | 7 marks

Answer 28

1. Interphase 2. Prophase 3. Prometaphase (Late prophase) 4. Metaphase 5. Anaphase 6. Telophase 7. Cytokinesis (Daughter Cells )

Question 29

All Stages of Meiosis (in order) | 15 marks

Answer 29

Meiosis I 1. Interphase 2. Prophase I 3. Prometaphase I (Late Prophase) 4. Metaphase I 5. Anaphase I 6. Telophase I 7. Cytokinesis Meiosis II 8. Prophase II 9. Prometaphase II 10. Metaphase II 11. Anaphase II 12. Telophase II 13. Cytokinesis

Question 30

Stages of Meiosis I (in order) | 7 marks

Answer 30

1. Interphase 2. Prophase I 3. Prometaphase I (Late Prophase) 4. Metaphase I 5. Anaphase I 6. Telophase I 7. Cytokinesis

Question 31

Stages of Meiosis II in order | 6 marks

Answer 31

1. Prophase II 2. Prometaphase II 3. Metaphase II 4. Anaphase II 5. Telophase II 6. Cytokinesis