Question

Assertion [A]: The species that invade a bare area are pioneer species 
Reason [R]: In primary succession, lichens or Phytoplanktons invade rocks and water respectively

• A. A and R are correct. R is the correct explanation of A
• B. A and R are correct. R is not the correct explanation of A
• C. A is correct but R is incorrect
• D. A is incorrect but R is correct

Hint:

In ecology, primary succession begins with pioneer species that can survive in harsh conditions and help create an environment for future organisms.

Answer 1

The Correct Option is A

Assertion (A): The assertion states that species that invade bare areas are pioneer species. This is indeed correct. Pioneer species are the first organisms to colonize barren or disturbed habitats. These species prepare the ground for other species that will follow in later stages of succession. Examples of pioneer species include lichens, mosses, and some types of bacteria. 
Reason (R): The reason states that during primary succession, lichens or phytoplanktons invade rocks and water respectively. This is also correct. In primary succession, there is no soil present, and lichens (in terrestrial habitats) or phytoplanktons (in aquatic habitats) are the first organisms to colonize bare rocks or water surfaces. They help in the breakdown of rocks into soil, which is a necessary step for the development of a complex ecosystem.

Since both the assertion and reason are true, and the reason provides a correct explanation for the assertion, the correct answer is (1) A and R are correct. R is the correct explanation of A.

Answer 2

To solve the problem, we need to analyze the assertion and reason provided, and determine whether they are correct and if the reason correctly explains the assertion.

1. Understanding the Assertion [A]:
The assertion states that the species that invade a bare area are pioneer species. This is a well-established concept in ecological succession. Pioneer species are the first organisms to colonize bare or disturbed land, such as rocks, which have not previously supported life.

2. Understanding the Reason [R]:
The reason given is that in primary succession, lichens or phytoplankton invade rocks and water, respectively. This is accurate because lichens are typically the first organisms to colonize bare rock surfaces during primary succession, and phytoplankton are often the first organisms to inhabit aquatic environments.

3. Conclusion:
Both the assertion and the reason are correct, and the reason correctly explains the assertion. The reason provides a valid explanation of how pioneer species, such as lichens and phytoplankton, are the first to colonize bare areas (rocks and water) during primary succession.

Final Answer:
The correct answer is Option A: A and R are correct. R is the correct explanation of A.