Match each environmental change with its description. Chemicals react with water and oxygen that enter water systems.

arrowBoth

Nutrients in excessive amounts enter water systems, causing algal bloom.

arrowBoth

A high concentration of toxic chemicals is present in the bodies of animals at the highest trophic levels.

arrowBoth

The question is incomplete, the missing part i.e. the environmental change is:

(A) biomagnification

(B) acid rain

(C) eutrophication

The answers are:

1. Acid rain- Chemicals react with water and oxygen that enter water systems.

2. Eutrophication- Nutrients in excessive amounts enter water systems, causing algal bloom.

3. Biomagnification- A high concentration of toxic chemicals is present in the bodies of animals at the highest trophic levels

Explanation:

1. Acid rain is an environmental disorder in which rainfall becomes acidic due to pollution. The pollution is as a result of the release of gaseous chemicals e.g sulfur, nitrogen oxide, which are produced by industries, into the atmosphere. These chemicals then react with water in the atmosphere to form acidic solutions, which then falls back as rain. Hence, chemicals reacting with water and oxygen that enter water systems describes ACID RAIN.

2. Eutrophication is the pollution of water bodies with substances containing chemicals like nitrogen, phosphorus etc. The chemicals, which are in excess, serve as nutrients to algae, which uses them to grow excessively forming a bloom called ALGA BLOOM. Hence, nutrients in excessive amounts entering water systems, causing algal bloom describes EUTROPHICATION.

3. Biomagnification refers to the build up or accumulation of toxic chemical substances in the body systems of living organisms higher up in the food chain. Pollutants like pesticides, herbicides flow into water bodies and are absorbed by certain aquatic organisms. When these organisms are fed on by consumers, the harmful substances accumulates in their tissues until it reaches a maximum concentration. Hence, a high concentration of toxic chemicals present in the bodies of animals at the highest trophic levels describes BIOMAGNIFICATION.

one centimetre is equal to 0.01 metres