Test: Animals - Class 6 MCQ

The sloth is known to have the longest sleep hours among animals. Sloths can sleep for up to 20 hours a day. This is because of their slow metabolism and energy-efficient lifestyle, as they spend most of their time resting in the trees.

• Option A (Cow): Cows sleep for around 4-5 hours per day.
• Option B (Horse): Horses typically sleep for about 2-3 hours a day, usually in short intervals.
• Option D (Cat): Cats sleep for around 12-16 hours a day, but not as long as sloths.

Thus, the correct answer is Option C.

Malaria is spread by the Anopheles mosquito. These mosquitoes carry the Plasmodium parasite, which causes malaria when it bites a person.

• Option A (Aedes): The Aedes mosquito is responsible for spreading diseases like dengue, Zika, and chikungunya, not malaria.
• Option C (Culex): The Culex mosquito is known to spread diseases like Japanese encephalitis and filariasis, but not malaria.
• Option D (None of these): This is incorrect because the Anopheles mosquito spreads malaria.

Thus, the correct answer is Option B (Anopheles).

A represents a centipede whereas B represents a millipede. Option 1 is incorrect as millipedes have 2 pairs of legs per body segment while centipedes have 1 pair of legs per body segment.

The organism described in the question undergoes a change in its breathing process from gills to lungs as it matures. This is characteristic of a frog.

• Frog: Baby frogs (tadpoles) breathe through gills in the water, but as they grow and become adult frogs, they develop lungs and breathe air on land.
• Whale: Whales breathe through lungs from birth, as they are mammals and live in water.
• Crocodile: Crocodiles also breathe through lungs throughout their life, both as juveniles and adults, despite spending time in water.
• Fish: Fish breathe through gills throughout their life and do not transition to lungs.

Thus, the correct answer is Option C (Frog).

Invertebrates are organisms that lack a backbone or a vertebral column. This includes a wide variety of animals, such as insects, worms, mollusks, and others.

• Option A (Organisms which lack backbone): This is the correct definition of invertebrates.
• Option B (Organisms which possess vertebral column): This refers to vertebrates, not invertebrates.
• Option C (Organisms which lack tail and bones): This description is too vague and does not specifically refer to invertebrates.
• Option D (Organisms which possess scaly skin): This describes some vertebrates, particularly reptiles, not invertebrates.

Thus, the correct answer is Option A.

The description matches the characteristics of a Goat:

• Eats plant parts: Goats are herbivores and feed on plant material such as grasses, leaves, and shrubs.
• Gives birth to young ones: Goats give birth to live young ones (kids).
• Feeds them with milk: Like all mammals, female goats nurse their young with milk.
• Option A (Fox): Foxes are carnivores, not herbivores, and do not feed their young with milk in the same way.
• Option C (Tiger): Tigers are carnivores, not herbivores, and do not fit the plant-eating description.
• Option D (Lion): Lions are carnivores and are not plant-eating animals.

Thus, the correct answer is Option B (Goat).

• Molluscs are organisms that typically have hard shells covering their bodies. Examples include snails, clams, oysters, and squids. The shell is made of calcium carbonate and serves as protection.
• Option A (Poriferans): These are simple aquatic organisms, also called sponges, that do not have shells. They have a porous body structure.
• Option B (Annelides): Annelids, like earthworms, do not have shells. They are segmented worms with soft bodies.
• Option D (Arthropods): Arthropods, such as insects, crustaceans (like crabs), and spiders, have exoskeletons, not shells.

Thus, the correct answer is Option C (Molluscs).

Malaria is caused by the Plasmodium parasite, which is transmitted to humans through the bite of an infected female Anopheles mosquito. The female mosquito is the one that feeds on human blood, which is necessary for the development of the parasite.

• Option B (Male Mosquito): Male mosquitoes do not bite humans and are not involved in spreading malaria.
• Option C (Female Insect): This is partially correct since the female mosquito transmits the disease, but the specific mosquito involved is the Anopheles species.
• Option D (Male Insect): Male insects do not spread malaria.

Thus, the correct answer is Option A (Female Mosquito).

• Echinoderms are marine animals that belong to the phylum Echinodermata. They typically have a hard, spiny exoskeleton and radial symmetry. Examples include:

  • Starfish (Option A)
  • Sea urchins (Option B)
  • Antedon (Option D), which is a type of feather star, also an echinoderm.

• Hydra (Option C), however, is not an echinoderm. It is a simple, freshwater animal that belongs to the phylum Cnidaria, not Echinodermata. It has a tubular body and radial symmetry but lacks the features characteristic of echinoderms.

Thus, the correct answer is Option C (Hydra).

The organism described in the question matches the characteristics of an Earthworm:

• Tube-shaped, segmented worm: Earthworms are segmented and cylindrical in shape.
• Found in the phylum Annelida: Earthworms belong to the phylum Annelida, which consists of segmented worms.
• Found in soil, feeding on live and dead organic matter: Earthworms live in soil and feed on decomposing organic matter, playing a crucial role in soil aeration and nutrient cycling.
• Digestive system runs through the length of its body: Earthworms have a complete digestive system that stretches from the mouth to the anus.
• Respiration through skin: Earthworms respire through their moist skin, absorbing oxygen and releasing carbon dioxide.
• Option B (Leech): While leeches are also segmented worms in the phylum Annelida, they are parasitic and typically feed on the blood of other animals, not organic matter in soil.
• Option C (Sycon): Sycon is a type of sponge, not a worm.
• Option D (Ascaris): Ascaris is a parasitic roundworm, not an earthworm.

Thus, the correct answer is Option A (Earthworm).