1.1. The dominant grass species in an African grassland ecosystem are star grass and red oat grass.

• Star grass is eaten by antelope species, such as topi and Thomson’s gazelle.

• Smaller animals such as mice and grasshoppers feed on red oat grass.

• Topi and Thomson’s gazelle are eaten by predators such as cheetahs, lions and serval cats.

• Grasshoppers and mice are eaten by serval cats and tawny eagles.

• Vultures feed on dead mammals.

Fig. 1 shows part of the food web for this ecosystem.

Fig. 1

Complete the food web by writing the names of the correct organisms in the boxes in Fig. 1.

1.2. Name the trophic level of the following species.

(i) Star grass

[1]

(ii) Topi

[1]

1.3. (i) State the principal source of energy for the food web shown in Fig. 1.

[1]

(ii) State what happens to energy when it leaves a food web.

[1]

1.4. Explain why there are no more than four trophic levels in the food web shown in Fig. 1.

1.5. Extended only

Fish such as salmon can be reared intensively in fish farms. They are fed on high protein food made from animals. When eating this food, the fish are feeding as secondary consumers.

Describe the disadvantages of intensive farming, such as salmon farming, for producing human food.