National 4 Revision Photosynthesis and Food Production

What do plants use nitrogen for?

• To make carbohydrates

• To make proteins

• To make fats

• To make sugar

What do plant absorb from the soil?

• Sugar

• Fat

• Nitrates

• Ammonia

What can be added to increase the nitrate content of the soil?

• Fertilisers, ammonia or compost

• Sugar, manure or compost

• Pesticides, manure or compost

• Fertilisers, manure or compost

What stages of the nitrogen cycle involve bacteria?

• nitrates produced in the soil and decomposers breaking down nitrogen into waste material.

• nitrates produced in the soil and absorption of nitrates in the soil

• production of plant protein and amino acids in plants passing into animals through feeding

• nitrates produced in the soil and excretion of waste materials and death of organisms.

What does stage 1 represent in the nitrogen cycle?

• Absorption of proteins into the soil.

• Absorption of nitrates into the soil.

• Absorption of sugar into the soil.

• Absorption of ammonia into the soil.

What does stage 3 represent in the nitrogen cycle?

• Ammonia in plants pass into animals through feeding.

• Nitrates in plants pass into animals through feeding.

• Amino acids in bacteria pass into animals through feeding.

• Amino acids in plants pass into animals through feeding.

What does stage 4 of the nitrogen cycle represent?

• Excretion of waste materials and death of organisms.

• Excretion of nitrate and death of organisms.

• Excretion of waste materials and growth of organisms.

• Excretion of sugar and death of organisms.

What does stage 5 represent in the nitrogen cycle?

• Decomposers break down sugar in dead and waste material.

• Decomposers break down fats in dead and waste material.

• Decomposers break down nitrogen in dead and waste material.

• Decomposers break down carbon dioxide in dead and waste material.

What is an advantage of using fertilisers?

• Crops will smell nicer

• Crops are less likely to be eaten by pests

• Crops grow slower

• Crops grow faster

What is a disadvantage of using fertilisers?

• Crops will grow slower

• Algal blooms may form

• Crops will be bigger

• Higher crop yield