MCQs Based On Environment – (55)

Correct Option: 3. Octopus
Explanation:
• Octopus belongs to the mollusk phylum and is an invertebrate, meaning it has no backbone.
• It is a soft-bodied marine animal with eight limbs and a highly developed nervous system.
• The other animals listed (frog, lizard, pigeon) are vertebrates with internal skeletons.
• Over 98% of animal species on Earth are invertebrates.

Correct Option: 1. Arthropods
Explanation:
• Arthropods are the largest group of invertebrates, including insects, arachnids (spiders), and crustaceans (crabs, lobsters).
• They have an exoskeleton (hard outer covering), segmented bodies, and jointed appendages that allow flexibility and movement.
• Unlike mollusks, which may or may not have shells, arthropods are completely encased in a protective exoskeleton that must be molted for growth.

Correct Option: 1. Starfish
Explanation:
• Echinoderms are marine animals with radial symmetry, a water vascular system, and tube feet for movement.
• Starfish, also known as sea stars, are the most well-known echinoderms.
• They have the ability to regenerate lost arms and are important members of ocean ecosystems.
• Earthworms are annelids, snails are mollusks, and amoeba are protozoans.

Correct Option: 1. Snake
Explanation:
-Snakes are reptiles, and reptiles are: • Cold-blooded (ectothermic)
• Covered with scales
• Mostly egg-laying (oviparous)
• Have ear holes instead of external ears
-Frogs are amphibians, dolphins are mammals, and sparrows are birds—all of which have very different characteristics.

Correct Option: 3. 5.8%
Explanation:
• The Western Ghats cover 5.8% of India’s land area and run parallel to the western coast.
• They are one of the eight “hottest hotspots” of biodiversity in the world, known for high endemism—many plant and animal species here are found nowhere else on Earth.
• They also play a vital role in monsoon regulation and water conservation in peninsular India.