Question

Which one of the following is a characteristic feature of cropland ecosystem?

• A. Absence of soil organisms
• B. Least genetic diversity
• C. Absence of weeds
• D. Ecological succession

Answer 1

The correct option is D

Explanation of the correct answer:

1. Cropland is a man-made ecosystem.

2. Reduced genetic variety is the feature of the cropland ecosystem.

3. It happens because croplands are aimed at producing mainly one or two species of plant at a time.

4. Since, maximum plants are of same same species, therefore, the genetic variation is less.

Explanation of the incorrect answers:

Option A:

1. The main producers of the cropland ecosystem include crop plants and weeds.

2. Weeds like Cynodon dactylon, Euphorbia hirta, Alysicarpus and Launaea nudicaulis are very widespread in cropland ecosystem.

Option B:

1. Common decomposers of any cropland habitats are bacteria and fungi such as Bacillus, Aspergillus, Agaricus, Mucor, Clostridium, and Fusarium.

2. These all are found in soil mainly.

Option C:

1. Ecological succession occurs in essentially lifeless - regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes or rocks left from a retreating glacier.
2. Croplands are usually fertile and the best for sustaining plant life.

Final answer: Least genetic diversity is a characteristic feature of cropland ecosystem.