problem 1) Classify the following animals as either carnivores or herbivores:

cow, rabbit, dog, shark, sheep, deer, lion, eagle, giraffe, seal, grass snake, horse

problem 2) Classify the following as producers, primary consumers or secondary consumers:

caterpillar, falcon, mouse, tree, phytoplankton, pike, cat, grass, locust, goat, otter, wheat

problem 3) A meal consists of grilled trout, potatoes and mushrooms. Describe how each item is ultimately a product of photosynthesis.

problem 4) On average, what percentage of sun's energy, which reaches surface of the Earth, is used for photosynthesis?

(a) 100%

(b) 10% 

(c) 1%

(d) 0.1 %

problem 5) On average, what percentage of the food given to cattle is converted to flesh and bone?

(a) 100% 

(b) 10% 

(c) 1 % 

(d) 0.1 % 

problem 6) Select the most suitable words from the list below to complete the following paragraph.

In a food chain, …… passes from one …… to another. The ……of the …… is always less than that of the ……because most of the food eaten by the …… is used to produce ……rather than new growth.

biomass, sunlight, trophic level, photosynthesis, producers, energy, consumers, decomposers

problem 7) Which two major groups of organisms make up the bulk of the decomposers?

problem 8) What processes (a) remove and (b) add to the carbon dioxide in the air?

problem 9) What part do (a) nitrifying, (b) nitrogen-fixing and (c) denitrifying bacteria play in the nitrogen cycle?

problem 10) What processes remove nitrates from the soil?

problem 11)(a) In what ways do farmers try to improve the quality of (i) their soil, (ii) their crop plants?   

(b) prepare the steps which farmers take to maximise the yield from their crops.