Free Environment and Atmosphere MCQs with Answers

121. The floral part that produces pollen grains is:

• A. Sepal
• B. Petal
• C. Anther
• D. Ovary

Explanation: The anther is the pollen-producing part of the stamen, the male reproductive structure of a flower. Sepals and petals protect or attract, while the ovary contains ovules.

122. Gravity setting chambers are used in industries to remove ________?

• A. NOx
• B. SOx
• C. CO
• D. Suspended particulate matter

Explanation: A gravity settling chamber slows a gas stream so that suspended solid particles settle under gravity. It is therefore used to remove suspended particulate matter, not gaseous pollutants such as NOx, SOx or CO.

123. Saffron is obtained from which among the following parts of the plant ________?

• A. Anther
• B. Stigma
• C. Stamen
• D. Pollen

Explanation: Saffron consists of the dried red stigmas of the Crocus sativus flower. The stigma is part of the female reproductive organ, while anthers and pollen belong to the male side.

124. Which one of the following clouds is found at the highest level in the atmospher?

• A. Stratus
• B. Cumulus
• C. Stratocumulus
• D. Cirrus

Explanation: Cirrus clouds are thin, wispy clouds made mostly of ice crystals and occur at the highest altitudes. Stratus, cumulus and stratocumulus clouds generally form at lower levels.

125. What would you find in a Vivarium?

• A. microorganisms
• B. Animals
• C. Humans
• D. None of these

Explanation: A vivarium is an enclosed place designed for keeping and observing living animals, often under controlled conditions. It may also contain plants, but “animals” is the best option provided.

126. _______________ causes biomagnification problem in the Ecosystem.

• A. Lead
• B. Mercury
• C. Chromium
• D. Copper

Explanation: Mercury accumulates in organisms and becomes increasingly concentrated at successive levels of a food chain, especially in fish-eating animals. This increase in concentration is called biomagnification.

127. The process in which seed grows in to a new plant is called ______?

• A. Fertilization
• B. Germination
• C. Vernalization
• D. None of these

Explanation: Germination begins when a seed absorbs water and resumes growth, producing a root and shoot that develop into a new plant. Fertilization forms the seed, whereas vernalization is cold treatment that promotes flowering.

128. Which of the following are Biodegradable ___________?

• A. Cans
• B. Dead Plants
• C. Glass
• D. None of these

Explanation: Dead plants are biodegradable because microorganisms can break their organic matter into simpler substances. Cans and glass generally persist much longer and are non-biodegradable in ordinary conditions.

129. Which of the following are non-biodegradable materials ______?

• A. Dead Animals
• B. Plastics
• C. Bread
• D. None of these

Explanation: Plastic is non-biodegradable because most microorganisms cannot naturally decompose its long polymer chains. Dead animals and bread are organic materials that decompose relatively readily.

130. The main cause of air pollution is __________?

• A. Burning Of Fuels
• B. Forests
• C. Fertilizers
• D. None of these

Explanation: Burning fuels releases smoke, carbon monoxide, nitrogen oxides, sulphur compounds and particulate matter into the air. Forests generally remove carbon dioxide, while fertilizers mainly cause soil and water pollution, although they can also contribute to air pollution.