Category: O level Biology

Reproduction is a characteristic of all living organisms. It is the process that makes more of the same kind of organism. Reproduction is essential in all species to ensure that the species does not extinct.

The human transport system is a system of tubes with a pump and valves to ensure one way blood flow. We need a transport system to deliver oxygen, nutrients and other substances to all our body cells, and take away waste products from them.

Animals eat to grow, repair etc. They simply eat to live. In this unit we will study how animals make use of what they eat.

We rarely think about breathing unless we’re out of breath. The act of breathing is part of the respiratory system, a complex process where air travels into and out of the lungs.

Just like humans, plants have a transport system of vessels and cells that transports water, minerals and other nutrients around the plant.

Plants are living organisms, they need food in order to keep living. The way they obtain their nutrients however, is completely different than that of ours. Plant make most of their nutrients by them selves, they just need 2 raw materials, these water and carbon dioxide.

Sense organs are the organs through which we sense or detect changes in the external environment. Each sense organ has special sensory cells, which receive the stimuli and transmit the impulses produced through the concerned nerve to the brain or the spinal cord.

A drug is any externally administered chemical substance (other than food) that modifies or affects chemical reactions in the body.

Excretion is the process by which metabolic waste products and toxic materials are removed from the body of an organism.