Question

Which of the following statements are correct?
Species that invade a bare area are called: Pioneer species.
In primary succession on rocks, the pioneers are usually lichens.
In primary succession in water, the pioneers are reed swamps. In secondary succession,
species that invade depend on soil, water, and environment.
Choose the correct answer from the options given below:

• A. (A), (B), and (D) only
• B. (A), (B), and (C) only
• C. (A), (B), (C), and (D)
• D. (B), (C), and (D) only

Answer 1

The Correct Option is A

To determine which statements are correct, let's evaluate each one: 

(A) Species that invade a bare area are called: Pioneer species.
This statement is correct. Pioneer species are the first to colonize a bare substrate in both primary and secondary succession.

(B) In primary succession on rocks, the pioneers are usually lichens.
This statement is correct. Lichens are often the first organisms to colonize bare rock because they can survive harsh conditions and contribute to soil formation.

(C) In primary succession in water, the pioneers are reed swamps.
This statement is incorrect. In primary succession that occurs in aquatic environments, algae and phytoplankton are usually the pioneering species, not reed swamps.

(D) In secondary succession, species that invade depend on soil, water, and environment.
This statement is correct. Secondary succession occurs in environments where soil is already present, and the species that invade are influenced by the specific conditions of that environment.

Based on this evaluation, the correct statements are (A), (B), and (D). Therefore, the correct answer is: (A), (B), and (D) only

Answer 2

The correct statements are (A), (B), and (D) only.

Additional Context:

• (A) Pioneer Species:
  • First colonizers of bare/disturbed areas
  • Examples: Lichens on rocks, algae in water
• (B) Primary Succession on Rocks:
  • Lichens secrete acids to break rock into soil
  • Form biological crusts enabling moss growth
• Why (C) is Incorrect:
  • Reed swamps appear later in aquatic succession
  • True pioneers are phytoplankton/zooplankton
• (D) Secondary Succession:
  • Occurs after disturbances (fires, floods)
  • Soil nutrients and seed bank influence species
• Succession Timeline:
  • Primary: Centuries to millennia
  • Secondary: Decades to centuries

Correct Answer: (1) (A), (B) and (D) only.