Free Biodiversity and Variety of Life MCQs with Answers

731. Which of the following endoparasites of humans does show viviparity?

• A. Trichinella spiralis
• B. Ascaris lumbricoides
• C. Taenia
• D. Enterobius vermicularis

Explanation: Trichinella spiralis is a minute nematode parasite that shows viviparity i.e., produces live youngs (larvae) not eggs. The adults of T. spiralis live in the human small intestine, where the females release large numbers of larvae. These larvae bore through the intestine and can cause trichinosis or trichiniasis which has symptoms like diarrohea, nausea, vertigo, pain in limbs and fever etc. Humans get infected after eating imperfectly cooked meat infected with the parasite's larval cysts.

732. Which of the following animals is not viviparous?

• A. Platypus
• B. Whale
• C. Flying fox (Bat)
• D. Elephant

Explanation: 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 each is 2.5 cm long.

733. Which of the following characteristics is mainly responsible for diversification of insects on land?

• A. Exoskeleton
• B. Eyes
• C. Segmentation
• D. Bilateral symmetry

Explanation: Exoskeleton made of cuticle has enabled insects to live on land and to diversify to almost all the possible habitats. It gives them protection, support and also helps to prevent desiccation.

734. Select the taxonomy mentioned that represents both marine and fresh water species.

• A. Echinoderms
• B. Ctenophora
• C. Cephalochordata
• D. Cnidaria

Explanation: Cnidarians are the sac-like animals which are aquatic. They are mostly marine except a few like hydra which are fresh water. They are the simplest organisms that have attained a tissue level of organization. Members of Ctenophora, Cephalochordata and Echinodermata are exclusively marine.

735. Which one of the following living organisms completely lacks a cell wall?

• A. Cyanobacteria
• B. Sea fan (Gorgonia)
• C. Saccharomyces
• D. Blue green algae

Explanation: Gorgonia (sea fan) is an animal belonging to phylum Coelenterata. All animals lack a cell wall.

736. Planaria possesses a high capacity of:

• A. Metamorphosis
• B. Regeneration
• C. Alternation of generation
• D. Bioluminescence

Explanation: Planaria possesses high degree of regeneration. Both epimorphosis (in which the missing parts are formed) and morphallaxis (in which the whole body can be regenerated from a fragment of the body) occur.

737. Which of the following are correctly matched with respect to their taxonomic classification?

• A. Housefly, butterfly, Insecta tsetse fly, silverfish
• B. Spiny anteater, sea urchin, sea cucumber
• C. Flying fish, Cuttle fish, Pisces silver fish
• D. Centipede, millipede, Insecta spider, scorpion

Explanation: Houseflies, butterflies, tsetse flies, and silverfish all belong to the same phylum in the animal kingdom, which is Arthropoda. Spiny ant eater (Echidna) is a prototherian mammal whereas, sea urchins and sea cucumbers are echinoderms. Silver fish (Lepisma) is an insect, Cuttle fish (Sepia) is a mollusc and flying fish (Exocoetus) is a bony fish. Centipede is class chilopoda, Millipede is class diplopoda and Scorpion and Spider are class arachnida of Phylum Arthropoda.

738. One of the representatives of Phylum Arthropoda is:

• A. Puffer fish
• B. Flying fish
• C. Cuttle fish
• D. Silver fish

Explanation: Phylum Arthropoda is the largest phylum of Animalia which includes insects. Examples include Apis, silkworm, Laccifer, silver fish (Lepisma), locust, etc. Puffer fish and flying fish (Exocoetus) are examples of superclass Pisces, while cuttle fish (Sepia) belongs to Mollusca.

739. The characteristics of Class Reptilia are:

• A. Body covered with moist skin which is devoid of scales, the ear is represented by a tympanum, alimentary canal, urinary and reproductive tracts open into a common cloaca
• B. Fresh water animals with bony endoskeleton, airbladder to regulate buoyancy
• C. Marine animals with cartilaginous endoskeleton, body covered with placoid scales
• D. Body covered with dry and cornified skin, scales over the body are epidermal, they do not have external ears

Explanation: Reptiles represent the first class of vertebrates fully adapted for life in dry places on land. The characters of reptiles are in fact a combination of characters that are found in fish and amphibians on one hand and birds and mammals on the other. Their exoskeleton is of horny epidermal scales, shields, plates and scutes. The skin is dry, cornified and devoid of glands. Reptiles lack external ears and have immovable eyelids.

740. Which one of the following groups of animals reproduces only by sexual means?

• A. Cnidaria
• B. Porifera
• C. Protozoa
• D. Ctenophora

Explanation: In ctenophores, asexual reproduction is absent. They are monoecious and fertilization is generally external. In cnidaria, asexual reproduction (budding) is found in the polyps and sexual reproduction is found in the medusa form. Both asexual and sexual reproduction occur in porifera (sponges). Asexual reproduction occurs by budding and gemmules. In protozoa, asexual reproduction takes place by binary fission, budding etc. and sexual reproduction takes place by syngamy and conjugation.