A
Only 2
B
Neither 1 nor 2
C
Both 1 and 2
D
Only 1
Correct answer: (c) Both 1 and 2
Explanation
- A
Only 2
Only 2. Blowholes are also keyed.
- B
Neither 1 nor 2
Neither. Both NCERT respiration lines hold.
- C
Both 1 and 2
Both 1 and 2. Cetaceans breathe through blowholes. Earthworms breathe through moist skin.
- D
Only 1
Only 1. Skin breathing of earthworms is also keyed.
Summary. Official key is (c) both. Blowholes for dolphin/whale; skin for earthworm. Also note: Blowhole — Modified nostril on the head; Cutaneous — Earthworm; must stay moist; Gills — Fish; not this pair; Lungs — Frogs have lungs plus skin.