[Maximum number: 1]

Fig. 3.2 shows the life cycle of a fern. The life cycle of a fern has some similarities and some differences compared with the life cycles of other plants.

The letters represent processes that occur during the life cycle.
The haploid stages of the life cycle are represented by (n).
The diploid stages of the life cycle are represented by (2 n).

Fig. 3.2

The adult sporophyte has 1200 chromosomes in its body cells.

State the number of chromosomes in the body cells of the gametophyte.

(a)

Sperm and eggs each have a nucleus which is haploid.

[ 2 ]

(i)

Define the term haploid nucleus.

[ 1 ]

(ii)

State the number of chromosomes in a human haploid nucleus.

[ 1 ]

[Maximum number: 1]

An alligator has 32 chromosomes in each of the cells of its nose.
How many chromosomes will an alligator zygote contain?

A

16

B

32

C

46

D

64

[Maximum number: 1]

Potatoes are stem tubers. A tuber can be placed in the ground to grow into another plant, which can grow many more tubers.

The diploid number of the potato plant is 24 .
How many chromosomes will there be in the cells of the stem, the leaf and the pollen?

stem

leaf

pollen

24

12

24

12

48

12

24

48

12

[Maximum number: 1]

A sperm cell from a domestic cat contains 19 chromosomes.
If this cell fertilises an egg, which zygote is produced?

A

diploid, with 19 chromosomes

B

diploid, with 38 chromosomes

C

haploid, with 19 chromosomes

D

haploid, with 38 chromosomes

[Maximum number: 1]

A haploid nucleus is defined as one that contains

A

one chromosome.

B

one set of unpaired chromosomes.

C

two chromosomes.

D

two sets of chromosomes.

[Maximum number: 1]

A zygote has ten chromosomes in its nucleus.
Which row shows the number of chromosomes in the cells of this species?

body cells

sperm cells

embryo cells

5

10

5

10

20

10

5

10

20

[Maximum number: 1]

Some descriptions of different human cells are listed.
1 contains 46 chromosomes
2 haploid nucleus
3 diploid nucleus
4 contains one set of unpaired chromosomes
Which descriptions are correct for the nucleus of a human gamete?

A

1 and 2

B

1 and 3

C

2 and 4

D

3 and 4

[Maximum number: 1]

Pollen grains grow tubes, which contain haploid male gamete nuclei.

Define the term haploid nucleus.

Question 3(b)(i)

Question 4

Question 4(d)

Question 4(d)(i)

Question 4(d)(ii)

Question 28

Question 28

Question 30

Question 30

Question 30

Question 30

Question 6(c)(ii)