Industrial wastes may contain metallic pollutants. State how such pollutants may indirectly reach and accumulate in the human body if the wastes were dumped into rivers. Name the causative agent of ch

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22. Industrial wastes may contain metallic pollutants. State how such pollutants may indirectly reach and accumulate in the human body if the wastes were dumped into rivers. (3mks).

• Metallic pollutants dumped into rivers are absorbed by aquatic plants and microorganisms.
• These contaminated organisms are then consumed by aquatic animals (e.g., fish), leading to bioaccumulation in their tissues.
• Humans then consume these contaminated aquatic animals (e.g., fish), causing the metallic pollutants to accumulate in human body tissues through a process called biomagnification.

23. Name the causative agent of cholera. (1mk)
The causative agent of cholera is the bacterium Vibrio cholerae.

24. State four features in the leaf which can be used for classification (4mks)

• Leaf arrangement (e.g., alternate, opposite, whorled)
• Leaf venation pattern (e.g., parallel, reticulate/net-like)
• Leaf margin (e.g., entire, serrated, lobed)
• Leaf shape (e.g., ovate, lanceolate, cordate)