Free Biodiversity and Variety of Life MCQs with Answers

921. Sharks and rays are included in class:

• A. Cyclostomata
• B. Osteichthyes
• C. Chondrichthyes
• D. Tetrapoda

Explanation: Chondrichthyes are cartilagenous fishes having exoskeleton of cartilage. Skates and rays are cartilagenous fishes.

922. Which of the following does not have specialized respiratory organs?

• A. Hydra
• B. Cockroach
• C. Birds
• D. Both A and B

Explanation: Hydra has neither blood and blood vessels, nor organs of excretion and respiration, which are carried on individually by each cell. Due to the thinness of the body wall and circulation of water in the gastrovascular cavity, most of the cells of the body remain freely exposed to the surrounding water.

923. Tse-Tse fly causes sleeping sickness and skin diseases by transmitting:

• A. Plasmodium
• B. Anopheles
• C. Trypanosoma
• D. Insects

Explanation: African trypanosomiasis, also called sleeping sickness, is a disease caused by a parasite. People can get this parasite when an infected Tsetse fly bites them. Symptoms include fatigue, high fever, headaches, and muscle aches. If the disease is not treated, it can cause death.

924. Book lungs are present in arthropods for the exchange of gases in class:

• A. Crustacea
• B. Myriapoda
• C. Insecta
• D. Arachnida

Explanation: Book lungs are a rudimentary type of lung typically found in arachnids, such as scorpions and spiders, and in horseshoe crabs.

925. Which of the following is the exclusive character of mammals?

• A. Homcothermic
• B. Poikilothermic
• C. Hair
• D. Four chambered heart

Explanation: Hair is a defining characteristic of mammals. Most mammals have hair or fur covering some or all of their bodies. This feature distinguishes them from other animal groups.

926. Fasciola is endoparasite of:

• A. Colon
• B. Small Intestine
• C. Liver
• D. Bile Duct

Explanation: Fasciola (Liver luke) : It is an endoparasite in sheep and occasionally in human beings. It has suckers used for attachment to host tissue. It completes its life cycle in two hosts, a snail, sheep or man. It lives in the bile duct of its hosts.

927. Trypanosoma is transmitted in human beings by:

• A. Plasmodium
• B. House Fly
• C. Anopheles
• D. Tsetse Fly

Explanation: Trypanosoma, the cause of sleeping sickness and skin diseases. The common house ly carries disease causing organisms to contaminate food and cause cholera, hepatitis etc. Some species of Trypanosoma cause diseases in cattle, also.

928. The cavity between the body wall and the alimentary canal is:

• A. Coelom
• B. Endoderm
• C. Mesoderm
• D. Mesoglea

Explanation: The coelom is a body cavity found in many animals, including vertebrates. It is located between the body wall and the alimentary canal (digestive tract) and is lined with mesoderm.

929. Amphibians evolved from:

• A. Cartilaginous fishe
• B. Reptiles
• C. Dipnoi
• D. Cyclostomata

Explanation: Dipnoi, also known as lungfishes, are a group of fish that can breathe air and are adapted to survive in oxygen-poor water. They are not direct ancestors of amphibians.

930. Amnion is not present around the embryo of:

• A. Reptiles
• B. Amphibian
• C. Birds
• D. Mammals

Explanation: In amphibians, the embryo is not surrounded by an amnion. The amnion is a membrane that forms a fluid-filled sac around the embryo in reptiles, birds, and mammals. This fluid-filled sac provides protection and helps regulate the embryo's temperature. However, in amphibians, this structure is absent, making option B the correct choice.