IGCSE Biology Paper-4: Specimen Questions with Answers 25 - 27 of 120

Explanation

World food supplies is related to food security, which means when all people, at all times, have physical and economic access to sufficient, safe, and nutritious food.

However, there are different problems are associated with world food supplies.

• Some parts of the world produce more than enough food for the people live there and in other parts about enough food or less than enough food produced.
• Transport related problems
• Natural causes like weather, flood and drought conditions
• High rate of human population

Explanation

Rods and cones sensory cells located on retina. Rods are very sensitive to low light level and it give black and white vision. Cones can properly works in bright light and mainly found in central part of the retina. The color we see depends on the combination of cones stimulated. Some people are missing one or more type of cone –they have disease of colorblindness.

Explanation

In living organism there are different properties are present which differ living entities to nonliving object some of them are as follows-

• Living organisms are made up from two types of cells either prokaryotic or eukaryotic
• For getting energy living organisms show metabolism process which may be of two types anabolism and catabolism
• Growth and development occur in all type of living organisms
• Formation of new generation is done by sexual or asexual reproduction process
• Living organism gives respond to external stimuli, which can be physical, chemical and biological.
• Self-regulation of the external environment is found in living organisms
• Every living organism has a definite life span of birth, growth, maturity and death.