Question

During ecological succession:

1. The number and types of animals remain constant
2. The gradual and predictable change in species composition occurs in a given area
3. The changes lead to a community that is in near equilibrium with the environment and is called pioneer community
4. The establishment of a new biotic community is very fast in its primary phase

• A. The number and types of animals remain constant
• B. The gradual and predictable change in species composition occurs in a given area
• C. The changes lead to a community that is in near equilibrium with the environment and is called pioneer community
• D. The establishment of a new biotic community is very fast in its primary phase

Answer 1

The correct option is B

The gradual and predictable change in species composition occurs in a given area

The correct option is B.

Explanation of correct option:

Ecological succession:

1. Ecological succession is the gradual and fairly predictable change in the species composition of a given area.
2. During succession, some species colonies area and their population become more numerous, whereas, the population of other species declines and even disappears.
3. It is a process of systematic progression of types of species invading an area.
4. There are two main types of succession, primary and secondary.

Explanation of incorrect option:

Option A:

1. During ecological succession, the number and types of animals does not remain constant.
2. The species population becomes numerous for some, whereas, the population of other species declines and even disappears.

Option C:

1. A pioneer community is one that inhabits an area in succession initially.
2. It is generally lichens in primary succession.
3. These communities undergo a series of stages and lead to a final climax community which is in equilibrium with the environment

Option D:

1. The primary succession or primary phase is comparatively slower by a new biotic community.
2. Since a disturbed area already has nutrient-rich soil, it is recolonized quickly in secondary succession.

Final Answer:

The ecological succession can be defined as the gradual and predictable change in the species composition of a particular area over a period of time.

Hence 2) is the correct answer as it defines the term ecological succession correctly.