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CAIE IGCSE Biology 16 Reproduction

Review asexual and sexual reproduction, flowering plants, human reproduction, sex hormones and sexually transmitted infections.

Syllabus
2026–2028
Course
Biology 0610

16. Reproduction question 1

[Maximum number: 6]

Fig. 2.1 shows a dwarf sunflower and a tall sunflower, Helianthus annuus. The height of the dwarf sunflower is 0.45 m and the height of the tall sunflower is 4.5 m .

not to scale

not to scale

Dwarf plants like the one in Fig. 2.1 have mutant alleles.

Question (a)

(a)

Fig. 2.3 shows how several strawberry plants can be formed from one parent plant.

Fig. 2.3

Fig. 2.3

[ 6 ]

Question (i)

(i)

Explain the type of reproduction that produces plants by the method shown in Fig. 2.3.

[ 3 ]

Question (ii)

(ii)

Explain the disadvantages of the type of reproduction shown in Fig. 2.3.

[ 3 ]

16. Reproduction question 2

[Maximum number: 5]

Question (a)

(a)

A scientist investigated sexual reproduction in flowering plants.

Fig. 2.1 shows the procedure for crossing two plants of the same species.

Fig. 2.1 shows the procedure for crossing two plants of the same species.

The scientist collected the seeds and germinated them. The leaves and flowers of the offspring plants showed phenotypic variation as they were not all identical to the parent plants.

The scientist then investigated the chromosomes of all the offspring plants and found that they had exactly the same number of chromosomes as the parent plants.

[ 5 ]

Question (i)

(i)

Suggest why the scientist placed a bag around flower 1.

[ 1 ]

Question (ii)

(ii)

Explain how sexual reproduction results in the variation that the scientist discovered in the offspring plants.

[ 2 ]

Question (iii)

(iii)

The chromosome number of the offspring plants is the same as the chromosome number of the parent plants in this investigation.

Explain how the chromosome number is maintained from one generation to the next.

[ 2 ]

16. Reproduction question 3

[Maximum number: 8]

Question (a)

(a)

Fig. 6.1 is a half-flower drawing of pride of Barbados, Caesalpinia pulcherrima.

Fig. 6.1

Fig. 6.1

Complete Table 6.1 by stating the letter from Fig. 6.1 that indicates the organ where each function occurs and the name of the organ.

Table 6.1

Table 6.1

[ 4 ]

Question (b)

(b)

Fig. 6.2 is a scanning electron micrograph of some pollen grains from wind-pollinated flowers and insect-pollinated flowers.

Fig. 6.2

Fig. 6.2

[ 2 ]

Question (i)

(i)

Explain how the pollen grain labelled J is adapted for insect pollination.

[ 2 ]

Question (c)

(c)

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

[ 2 ]

Question (i)

(i)

One of these male gamete nuclei fuses with the female gamete.

State the part of the flower that contains the female gamete.

[ 1 ]

Question (ii)

(ii)

Explain why it is important for gametes to be haploid.

[ 1 ]

16. Reproduction question 4

[Maximum number: 12]

Fig. 4.1 is a photograph of a bee on a flower. One of the bee's legs is covered with pollen.

Fig. 4.1

Fig. 4.1

Question (a)

(a)

State one way that pollen grains are adapted for pollination by bees.

[ 1 ]

Question (b)

(b)

Fig. 4.2 is a diagram of a cross-section of an insect-pollinated flower.

Fig. 4.2

Fig. 4.2

On Fig. 4.2, name and draw label lines to:
- the structure that supports an anther
- a structure that protects the flower bud
- an ovule.

[ 3 ]

Question (c)

(c)

Describe sexual reproduction in a flower, from the release of pollen to the formation of a zygote.

[ 5 ]

Question (d)

(d)

Sexual reproduction also occurs in humans.

[ 3 ]

Question (i)

(i)

State the name of the male gamete in a human.

[ 1 ]

Question (ii)

(ii)

State where gametes are formed in the human male reproductive system.

[ 1 ]

Question (iii)

(iii)

Describe the function of the prostate gland in the male reproductive system.

[ 1 ]
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