CBSE Class 9 Biology Diversity in Living Organisms MCQs Set 12

Answer: (c) Jointed appendages

Explanation:
1. All arthropods have jointed appendages, which is why the phylum is called Arthropoda.
2. Not all have wings or metamorphosis.

Teacher's Note:
1. Arthropod means jointed foot.
2. They also have a chitinous exoskeleton.

Answer: (c) Neopilina

Explanation:
1. Neopilina has shell and foot like a mollusc and segmentation like an annelid.
2. So it links the two phyla.

Teacher's Note:
1. Peripatus links annelids and arthropods.
2. Neopilina was discovered in 1952.

Answer: (a) Arthropoda; excretion

Explanation:
1. Green glands are the excretory organs of crustaceans, which are arthropods.
2. They are also called antennal glands.

Teacher's Note:
1. Prawns have green glands.
2. Do not confuse them with respiratory organs.

Answer: (d) Unsegmented, soft-bodied, usually aquatic animals with a shell mostly

Explanation:
1. Molluscs have a soft unsegmented body, are mostly aquatic and usually have a shell.
2. They are triploblastic.

Teacher's Note:
1. Examples are snail, octopus and Pila.
2. The shell is made of calcium carbonate.

Answer: (d) Starfish

Explanation:
1. Echinoderms like starfish have a water vascular system for movement.
2. It works with tube feet.

Teacher's Note:
1. It is a unique feature of the phylum.
2. Starfish also have radial symmetry.

Answer: (d) All of the above

Explanation:
1. Ctenophores, coelenterates and echinoderms show radial symmetry (adult echinoderms are pentamerous).
2. So all are possible.

Teacher's Note:
1. Larvae of echinoderms are bilateral.
2. Radial symmetry suits sessile life.

Answer: (d) All of the above

Explanation:
1. Starfish, Hydra and sponges like Leucosolenia can regenerate lost body parts.
2. So all are correct.

Teacher's Note:
1. Regeneration is a way of asexual reproduction in some.
2. Starfish can regrow an arm.

Answer: (a) Echinodermata

Explanation:
1. These features are typical of echinoderms like starfish.
2. They have a calcareous endoskeleton.

Teacher's Note:
1. They live only in the sea.
2. They have tube feet.

Answer: (d) An elastic rod-like structure (notochord)

Explanation:
1. The notochord is the defining feature found in all chordates at some stage.
2. It is a flexible rod below the nerve cord.

Teacher's Note:
1. In vertebrates it is replaced by the backbone.
2. Phylum Chordata is named after it.

Answer: (b) Vertebral column

Explanation:
1. The vertebral column is found only in vertebrates, not in all chordates.
2. The other three are essential chordate characters.

Teacher's Note:
1. Protochordates have a notochord but no backbone.
2. The backbone develops from the notochord.

Answer: (c) Reptiles

Explanation:
1. Reptiles have dry, horny scales that prevent water loss.
2. Amphibians have a moist skin without scales.

Teacher's Note:
1. This helps them live on land.
2. Snakes shed this skin.

Answer: (a) Tortoise

Explanation:
1. A tortoise is a reptile, which is cold-blooded (poikilothermic), and its body temperature changes with the environment.
2. The others are warm-blooded.

Teacher's Note:
1. Fishes, amphibians and reptiles are poikilothermic.
2. Birds and mammals are homeothermic.

Answer: (b) Archaeopteryx

Explanation:
1. Archaeopteryx had feathers and wings like a bird, and teeth and a tail like a reptile.
2. So it links reptiles and birds.

Teacher's Note:
1. It is known from fossils.
2. It shows that birds evolved from reptiles.

Answer: (b) Whale, pigeon, bat

Explanation:
1. Whales and bats are mammals and pigeons are birds, which are warm-blooded.
2. The other groups are cold-blooded.

Teacher's Note:
1. Birds and mammals keep a constant body temperature.
2. Reptiles, fishes and amphibians do not.

Answer: (b) Mammals

Explanation:
1. Only mammals have a muscular diaphragm separating the chest and abdomen.
2. It helps in breathing.

Teacher's Note:
1. Birds and reptiles have no diaphragm.
2. It is a unique mammalian feature.

Answer: (c) Unisexual, and sexual dimorphism is present

Explanation:
1. Birds have separate sexes, and the male and female often look different, as in peacock and peahen.
2. So they are unisexual with sexual dimorphism.

Teacher's Note:
1. Fertilisation is internal.
2. They lay hard-shelled eggs.

Answer: (b) Birds and mammals

Explanation:
1. Birds and mammals look after their young.
2. Most fishes, amphibians and reptiles do not.

Teacher's Note:
1. Birds incubate eggs and feed chicks.
2. Mammals suckle their young.

Answer: (d) Birds

Explanation:
1. Birds are warm-blooded like mammals.
2. Fishes, amphibians and reptiles are cold-blooded.

Teacher's Note:
1. Warm-blooded animals keep a constant body temperature.
2. They are also called homeotherms.

Answer: (b) Pavo cristatus

Explanation:
1. The Indian peafowl is Pavo cristatus.
2. Passer domesticus is the house sparrow.

Teacher's Note:
1. Columba livia is the pigeon.
2. Psittacula eupatria is the parakeet.

Answer: (b) A constant body temperature

Explanation:
1. Warm-blooded animals maintain a constant body temperature whatever the weather.
2. Cold-blooded animals change with the surroundings.

Teacher's Note:
1. Their blood is not cold.
2. They use energy from food to produce heat.

Answer: (b) Aves

Explanation:
1. Birds (Aves) have a four-chambered heart, nucleated RBCs and a toothless beak.
2. Mammal RBCs have no nucleus.

Teacher's Note:
1. Birds are warm-blooded.
2. They have feathers and lay eggs.

Answer: (c) Seven cervical vertebrae are found

Explanation:
1. Almost all mammals, even the giraffe and whale, have seven neck (cervical) vertebrae.
2. Platypus lays eggs and whales have no pinna.

Teacher's Note:
1. This is a true general feature.
2. Teeth number differs among mammals.

Answer: (b) Lungs

Explanation:
1. Whales are mammals and breathe air with lungs.
2. They come to the surface to breathe.

Teacher's Note:
1. Book lungs are found in spiders.
2. Fishes have gills.

Answer: (c) Rabbit and whale

Explanation:
1. Rabbit and whale are mammals and give birth to young ones, so they are viviparous.
2. Turtles and birds lay eggs.

Teacher's Note:
1. Most mammals are viviparous.
2. The embryo develops inside the mother.

Answer: (b) Mammals

Explanation:
1. Most mammals have an external ear, the pinna.
2. Other vertebrates lack it.

Teacher's Note:
1. The pinna collects sound.
2. Birds have no pinna either.

Answer: (c) Keep the body temperature constant in spite of changes in climatic temperature

Explanation:
1. Warm-bloodedness keeps the body temperature steady despite changes outside.
2. This allows enzymes to work well in all seasons.

Teacher's Note:
1. It lets mammals live in cold and hot places.
2. It needs a high food intake.