UPSC Prelims 2002 Q25: Science & Technology – Biology
Ticks and mites are actually
- (a) Arachnids
- (b) Crustaceans
- (c) Insects
- (d) Myriapods
Answer: (a) Arachnids
Explanation
Classification of ticks and mites
| Group | Characteristics and examples |
|---|---|
| Arachnida | Eight legs, no antennae, two body regions — ticks, mites, spiders, scorpions |
| Insecta | Six legs, three body parts, antennae |
| Crustacea | Two pairs of antennae; crabs, prawns |
| Myriapoda | Many legs; centipedes, millipedes |
Ticks and mites have eight legs and no antennae, so they belong to class Arachnida in phylum Arthropoda, along with spiders and scorpions. They are not insects.
Answer: (a) Arachnids.
Why each option is right or wrong
- (a) CORRECT. Ticks and mites are arachnids.
- (b) Incorrect. Crustaceans have two pairs of antennae.
- (c) Incorrect. Insects have six legs and antennae.
- (d) Incorrect. Myriapods are centipedes and millipedes.
Key point
Arthropod classes by legs: insects 6, arachnids 8, myriapods many, crustaceans 10 or more.
Remember
Ticks, mites, spiders and scorpions are arachnids.
Common mistakes
- Calling ticks and mites insects because they are small pests.
- Confusing arachnids with myriapods.
- Forgetting that they have no antennae.
Exam tip
Count the legs: eight legs means arachnid.
Sources
- NCERT Class XI Biology — Animal Kingdom (Arthropoda)
- Encyclopaedia Britannica — arachnid