Reproduction in Plants & Humans (CIE IGCSE Biology: Co-ordinated Sciences (Double Award))

Define the term pollination.

Extended Tier Only

Fig 1 shows a flower that reproduces using wind-pollination.

Fig 1

Describe two ways in which the flower in Fig. 1 is adapted for wind-pollination.

Fig. 2 shows two photomicrographs of pollen.

Fig 2

Describe, using your knowledge and the information in Fig. 2, how pollen from an insect-pollinated flower is different to pollen from a wind-pollinated flower.

Sexual reproduction in plants results in seeds being formed.

State three conditions needed for the germination of seeds.

Some insects can reproduce by sexual reproduction and asexual reproduction. In both types of reproduction chromosomes are passed from the parent or parents, to the offspring.

Fig. 1 shows a drawing of a parent insect and seven of her offspring: M, N, P, R, S, T and U.

Fig 1

Two of the offspring were produced by asexual reproduction.

Suggest the letters representing these two offspring.

[1]

Insect R was produced by sexual reproduction.

Use the information from the diagram to support this statement.

State the term that is defined as the observable features of an organism.

[1]

Complete the sentences by stating the part of the human body that produces male gametes and the part that produces female gametes.

Male gametes are produced by the ........................................................................

Female gametes are produced by the ...................................................................

Fig. 1 represents the early stages in the development of a female embryo.

Fig. 1

[3]

Fig. 1 shows a section through a flower.

Fig. 1

Write one letter from Fig. 1 to identify each of the following.

You may use each letter once, more than once, or not at all.

[6]

Fig. 2 shows pollen grains from the flowers of several different species, labelled with the letters K–Q.

Fig. 2

State the letters of the pollen grains that come from insect-pollinated flowers.

Extended Tier Only

Sugarcane is a crop plant that is usually grown from stem cuttings rather than from seeds.

Describe the advantages of using cuttings rather than seeds to reproduce crop plants.

Define the term sexual reproduction.

Fig. 1 shows some organs in the body of a man.

Fig. 1

Complete Table 1 by writing in the names of the parts labelled A to D in Fig. 1. 

Table 1

[4]

State the function of the scrotum.

Fig. 1 shows sections of two flowers, K and L, from the same species.

Fig. 1

[2]

State the names of the parts in Fig. 1 that: 

• produce ovules
• protect the bud of the flower

On Fig. 1, draw an arrow to represent the transfer of pollen from flower K to flower L during pollination.

A student said, “Flowers K and L are pollinated by insects.”

Describe two structures in flowers K and L that support this statement. 

Use features that are visible in Fig. 1. 

Describe the pathway water takes in a plant, as it moves from the soil to a leaf.

Extended Tier Only

Fig. 1 is a diagram of the human female reproductive system.

Fig. 1

Complete Table 1 by stating the letter from Fig. 1 that identifies the structure where each process occurs.

Table 1

[3]

State the name of the part of the female reproductive system labelled S in Fig. 1.

[1]

Extended Tier Only

Fig. 2 is a diagram of a human sperm cell.

Fig. 2

Write the formula that would be used to calculate the magnification of the diagram.

[1]

The actual length of the sperm cell in Fig. 2 is 0.055mm.

Convert this value to micrometres (μm).

Space for working.

___________ µm  [1]

Extended Tier Only

Explain why the nuclei of sperm cells differ from those of other cells in the male.

Extended Tier Only

Explain the roles of the flagellum, the mitochondria and the acrosome in sperm cells.

Explain why the sex of a child is determined by its father.

Extended Tier Only

Fig. 1 is a half-flower drawing of pride of Barbados, Caesalpinia pulcherrima.

Fig. 1

Complete Table 1 by stating the letter from Fig. 1 that indicates the organ where each function occurs and the name of the organ.

Table 1

Extended Tier Only

Fig. 2 is a scanning electron micrograph of some pollen grains from wind-pollinated flowers and insect-pollinated flowers.

Fig. 2

Write the formula that would be used to calculate the actual diameter of pollen grain H.

[1]

The actual diameter of pollen grain H is 0.082mm.

Convert this value to micrometres (μm).

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

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

One of these male gamete nuclei fuses with the female gamete. State the part of the flower that contains the female gamete

[1]

Define the term haploid nucleus.

Explain why it is important for gametes to be haploid.

Some students investigated the conditions needed for the germination of maize seeds. They used maize seeds from a packet of seeds they had purchased in a shop.

Three dishes were used, each containing cotton wool and the same number of maize seeds, as shown in Fig. 1.

Fig. 1

Table 1 shows the conditions provided for each dish. 

Table 1

The seeds were left for five days and then observed.

The results are shown in Table 2

Table 2

[2]

In a second investigation, maize seeds were placed in a dish containing damp cotton wool.

This dish was left in the dark for five days at 20°C.

Predict and explain the results.

[2]

A student gathered 70 maize seeds from plants growing in a field. The seeds were placed in dishes containing damp cotton wool.

After five days, only 64 seeds had germinated. 

Calculate the percentage of seeds that germinated.

Show your working.

Give your answer to the nearest whole number. 

[2]

Suggest a reason why some of the seeds did not germinate.

[1]