Among the following organisms, which one does not belong to the class of other three?
- (a) Crab ✓ UPSC's answer
- (b) Mite
- (c) Scorpion
- (d) Spider
Why the answer is (a)
• Mites, scorpions and spiders belong to the class Arachnida (eight legs, no antennae); the crab belongs to the class Crustacea (ten legs, two pairs of antennae) — option (a).
• All four are arthropods, but the crab is the odd one at class level.
• Hence option (a).
Why the other options are wrong
- (b) Mite
- Mites are arachnids like scorpions and spiders.
- (c) Scorpion
- Scorpions are arachnids.
- (d) Spider
- Spiders are arachnids.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2014, held on 24 August 2014. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.