Q4 of 8 Page 189

Communicable diseases are pathogenic diseases which are spread from person to person either directly or indirectly. Write the mode of transmission of the following diseases.

i) Cholera, typhoid


ii) Malaria

i) Cholera and typhoid are diseases caused by bacteria and spread through contaminated water, specially when there is absence of proper hygiene, or the water with standing water and it’s surroundings are not kept clean.

ii) Malaria is a disease caused by protozoan called Plasmodium, but spreads through vectors. Vectors are organisms , e.g. mosquitoes, that spread the disease from an infected person to a healthy individual (by , say mosquito bites) .


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i) Identify the following bacteria based on its shape.

ii) Draw and label the following parts of the bacteria.


a) Flagella b) pili c) cell wall cytoplasm cell membrane