Question

Given below are two statements
Statement I: The correct order of segments in an insect leg is coxa-trochanter- femur-tibia and tarsus
Statement II: In fossorial legs, the forelegs are greatly expanded and tibia is digitate
In light of the above statements, choose the most appropriate answer from the options given below

• A. Both Statement I and Statement II are correct
• B. Both Statement I and Statement II are incorrect
• C. Statement I is incorrect but Statement II is correct
• D. Statement I is correct but Statement II is incorrect

Hint:

To remember the sequence of insect leg segments from proximal to distal, use the acronym: C-T-F-T-T (Coxa, Trochanter, Femur, Tibia, Tarsus).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The insect leg is a segmented appendage attached to the pleuron of the thorax.
It is modified into different functional types to suit various ecological niches, such as running, digging, or grasping.

Step 2: Detailed Explanation:
Let us evaluate both statements regarding insect leg structure and modification:
1. Statement I: The standard insect leg consists of five primary segments arranged sequentially from proximal (nearest to the body) to distal:
- Coxa: The basal segment that articulates with the thorax.
- Trochanter: A small segment between the coxa and the femur.
- Femur: Typically the largest and strongest segment of the leg.
- Tibia: A long, slender segment located distally to the femur.
- Tarsus: The terminal portion, which is subdivided into smaller segments called tarsomeres.
Therefore, Statement I describes the correct order of leg segments and is correct.
2. Statement II: Fossorial legs are modified for digging and burrowing.
In insects with fossorial legs (such as mole crickets, family Gryllotalpidae), the forelegs are shortened, flattened, and widened.
The tibia is greatly expanded and possesses heavy, finger-like projections (digitate structures) that act as soil-excavating teeth.
Therefore, Statement II describes these morphological adaptations correctly.

Step 3: Final Answer:
Both Statement I and Statement II are correct.