Free Biodiversity and Variety of Life MCQs with Answers

821. A larval stage occurs in the life history of all members of which option?

• A. Frog, lizard and cockroach
• B. Ascaris, housefly and frog
• C. Housefly, earthworm and mosquito
• D. Butterfly, frog and mosquito

Explanation: In butterfly, the larval stage is known as catterpillar, in frog it is known as tadpole, while in mosquito it is known as wriggler.

822. Gorillas, chimpanzees, monkeys and humans belong to the same:

• A. Species
• B. Genus
• C. Family
• D. order

Explanation: Gorillas, chimpanzees, monkeys and humans belong to the same order i.e., primates. They have well developed brain flat nails on fingers and toes. First digit is usually opposable, an adaptation for grasping. Eyes are typically large and turned forward

823. What is common in whale, bat and rat?

• A. Absence of neck
• B. Muscular diaphragm between thorax and abdomen
• C. Extraabdominal testes to avoid high temperature of body
• D. Absence of body hair

Explanation: Whale, bat and rat are mammals. Diaphragm is present in mammals. The diaphragm separates the thoracic cavity (with lung and heart) from the abdominal cavity (with digestive system and urogenital system). In its relaxed state, the diaphragm is shaped like a dome. It is controlled by the phrenic nerve.

824. Which class do starfish belong to?

• A. Asteriodea
• B. Ophiuroidea
• C. Holothuroidea
• D. Crinodiea

Explanation: Starfish belong to the Class Asteroidea, characterized by the presence of five or more arms not sharply set off from a central disc. They are free living marine animals that occur on sandy or muddy bottoms and crawl about over rocks and shells. All are carnivorous, feeding mainly on crustaceans, polychaetes and molluscs. They also feed on detritus and plankton. They generally exhibit remarkable powers of autotomy and regeneration.

825. Eye of the molluscan group that resembles vertebrate eye is:

• A. Bivalvia
• B. Gastropoda
• C. Pelecypoda
• D. Cephalopoda

Explanation: In cephalopodas, paired eyes are large, efficient and bulge from the dorsolateral sides of the head. They bear striking resemblance to those of a vertebrate because a cornea, iris, lens and retina are present. Their lens projects an inverted image on the retina just like the vertebrate eye. External muscle attachments enable limited movements of the eye. But the embryological development of the cephalopod eye is entirely different from that of the vertebrate eye, and hence they areo homologically different. The vertebrate eye is formed as an outgrowth of the brain, while the cephalopod eye is formed by an ectodermal invagination.

826. The adult Culex and Anopheles can be distinguished with the help of:

• A. Mouth parts/colour
• B. Sitting posture
• C. Antennae/wings
• D. Feeding habits

Explanation: Two common mosquito genera, the Anopheles and Culex can be easily identified by their sitting postures. When sitting, the abdomen of Anopheles is always held at an angle to the surface while that of Culex is held parallel to the surface.

827. Sound box of birds is called:

• A. Pygostyle
• B. Larynx
• C. Syrinx
• D. Synsacrum

Explanation: At the posterior end or base of the trachea, at its junction with the bronchi, is found a special structure, the syrinx or voice box, concerned with sound production. It is characteristic of birds as it does not occur in other vertebrates.

828. What is the Ascaris larva called?

• A. Cysticercus
• B. Rhabditiform
• C. Hexacanth
• D. Onchosphere

Explanation: In Ascaris, the rhabditiform larva in the first stage is not infective. In a week's time, it moults within the egg shell and becomes a second stage rhabditoid which is capable of infecting the host. Cysticercus, hexacanth and onchosphere are the larval stages of Taenia.

829. What is correct about Taenia?

• A. Male organs occur in posterior proglottides
• B. Male organs occur in anterior proglottides
• C. Female organs occur in anterior proglottides
• D. Mature proglottides contain both male and female organs

Explanation: There are about 450 mature proglottids forming the middle part of strobila. These are large and squarish in outline. The anterior 100 to 150 proglottids contain only male reproductive organs, while the posterior 250 mature proglottids develop both male and female reproductive organs making them hermaphrodite.

830. What is an example of an egg laying mammal?

• A. Kangaroo
• B. Platypus
• C. Koala
• D. Whale

Explanation: The Duckbilled platypus is an egg laying mammal. It is found in the rivers in eastern Australia and Tasmania. It is a beaver like monotreme about 5060 cm long and well adapted to live in water. Usually, two eggs are laid at a time. The female curls around them for incubation and remains inactive for about two weeks. Newly hatched young ones are very immature, naked, blind and only 2.5 cm long.