Correct Option
The correct option is (a).
Explanation
Root systems in angiosperms are primarily classified into two types based on their origin and structure: the taproot system and the fibrous root system. These systems perform essential functions such as absorption of water and minerals, anchorage, and storage of food reserves.
Statement-wise Analysis
- Statement 1 is Correct: In a taproot system (characteristic of dicotyledonous plants like mustard), the primary root grows directly from the radicle and persists as the main central root. This main root is referred to as the taproot. Smaller roots that branch out from the taproot are termed lateral roots (secondary, tertiary, etc.).
- Statement 2 is Incorrect: In a fibrous root system (characteristic of monocotyledonous plants like wheat), the primary root is short-lived and is replaced by a large number of roots. These roots originate from the base of the stem rather than forming a single main root structure. Therefore, there is no dominant main root in a fibrous system.
- Statement 3 is Incorrect: One of the primary functions of the root system is to anchor the plant firmly to the soil. Roots penetrate the soil substrate, providing structural stability to the plant against wind and other forces.
Key Takeaway
Taproot systems feature a persistent main root with lateral branches (common in dicots), whereas fibrous root systems consist of a cluster of roots originating from the stem base (common in monocots). Both systems are critical for anchorage and absorption.