Free Biodiversity and Variety of Life MCQs with Answers

851. Which is not a true amphibian animal?

• A. Salamander
• B. Toad
• C. Tortoise
• D. Frog

Explanation: Tortoise belongs to the Class Reptilia. Its body is protected by a shell consisting of a dorsal carapace and ventral plastron.

852. A wood boring mollusc/shipworm is:

• A. Chiton
• B. Teredo
• C. Limax
• D. Patella

Explanation: The common name of Teredo is shipworm which belongs to the class bivalvia of the Phylum Mollusca. In it, the head is absent and the foot is wedge shaped for burrowing.

853. Silk thread is obtained from the silk moth during the:

• A. Pupal stage
• B. Larval stage
• C. Nymph stage
• D. Adult stage

Explanation: The mulberry silk moth has been the most commercially important and beneficial insect. The silk is obtained by killing the pupa inside hot water and the silk thread is then wound.

854. The frog's heart, when taken out of the body, continues to beat for sometime.Select the best reason for this from the following statements. (1) The frog is a poikilotherm. (2) The frog does not have any coronary circulation. (3) Its heart is "myogenic" in nature. (4) Its heart is autoexcitable.

• A. Only (4)
• B. (1) and (2)
• C. (3) and (4)
• D. Only (3)

Explanation: The frog's heart is myogenic, i.e. its heartbeat originates from muscles of heart. Hence, it is autorythmic. A wave of contraction originates from the sinus venosus and spreads to the wall of sinus venosus and both auricles. This compels the heart to beat. Due to this reason, the frog's heart will continue to beat as long as it gets a supply of ATP.

855. In male cockroaches, sperms are stored in which part of the reproductive system?

• A. Seminal vesicles
• B. Mushroom glands
• C. Testes
• D. Vas deferens

Explanation: Seminal vesicles are numerous small sacs present on ventral surface of anterior part of the ejaculatory duct which store sperms.

856. Smooth muscles are:

• A. Involuntary, fusiform and nonstriated
• B. Voluntary, multinucleate and cylindrical
• C. Involuntary, cylindrical and striated
• D. Voluntary, spindle-shaped and uninucleate

Explanation: Smooth muscle fibres are elongated and spindle shaped (fusiform). Each fibre contains a single oval nucleus surrounded by cytoplasm (sarcoplasm). In the cytoplasm, myofibrils are arranged longitudinally. These fibres lack striations and sarcolemma, however they are enclosed by a plasma membrane.

857. Which type of tissue correctly matches with its location?

• A. Transitional epithelium - tip of the nose
• B. Cuboidal epithelium - Lining of the stomach
• C. Smooth muscle - Wall of intestine
• D. Areolar tissue - Tendons of the nose

Explanation: Tip of the nose has elastic cartilage. Simple columnar epithelium lines the stomach. The tendons of the nose are not primarily composed of areolar tissue but rather consist of fibrous connective tissue. Posterior part of the intestine has a single unit smooth muscle in which all fibres of the muscle contract simultaneously as a single unit.

858. The body cells in cockroach discharge their nitrogenous waste in the haemolymph mainly in the form of:

• A. Urea
• B. Calcium carbonate
• C. Ammonia
• D. Potassium urate

Explanation: In cockroaches, Malpighian tubules extract metabolic wastes like potassium and sodium urate, water and carbon dioxide from the blood. In the Malpighian tubules, bicarbonates of potassium and sodium, water and uric acid are formed. A large amount of water and bicarbonates of potassium and sodium are reabsorbed by the cells of Malpighian tubules and then transferred to the blood (haemolymph). Uric acid is carried to the alimentary canal of the insect and is finally passed out through anus.

859. The terga, sterna and pleura of the cockroach's body are joined by:

• A. An arthrodial membrane
• B. Cartilage
• C. Cementing glue
• D. Muscular tissue

Explanation: The arthrodial membrane is a tough, flexible cuticle that joins the skeletal elements of cockroach and other arthropods. It connects terga, pleura and sterna of the cockroach's body.

860. Choose the correctly matched pair.

• A. Tendon = Speciliazed connective tissue
• B. Adipose tissue = Dense connective tissue
• C. Areolar tissue = Loose connective tissue
• D. Cartilage = Loose connective tissue

Explanation: Areolar tissue is the most widely distributed loose connective tissue in the body. Tendon is a type of dense connective tissue, adipose tissue is a fat storing loose connective tissue and cartilage is a specialized connective tissue.