Free Biodiversity and Variety of Life MCQs with Answers

1021. Which of the following is not associated to exoskeleton of arthropods?

• A. Non-living
• B. Secreted by endodermis
• C. Acellular
• D. Polysaccharide in nature

Explanation: The exoskeleton is secreted by a layer of cells called the epidermis, which is located beneath the existing exoskeleton. As the arthropod grows, it molts or sheds its old exoskeleton in a process called ecdysis and secretes a new, larger exoskeleton to accommodate its increased size.

1022. Which of the following is incorrect about annelida?

• A. Triploblastic organisation.
• B. Bilateral symmetry
• C. Segmentation
• D. Pseudocoelom

Explanation: Pseudocoelom is not possessed by annelida. It is the major characteristic of phylum nematoda.

1023. The internal buds are known as which of the following?

• A. Spicules
• B. Choanocytes
• C. Gemmules
• D. Both A and B

Explanation: Gemmules are the internal buds in poriferans.

1024. How is the body plan of a lobster similar to that of a whale?

• A. Closed circulatory system
• B. Mouth develops from the blastopore
• C. A tubular digestive system with mouth and an anus
• D. The gut is not lined by coelomic epithelium

Explanation: Arthropods and chordates also have tubular digestive system with mouth and an anus.

1025. The nervous system of arthropods has:

• A. A brain, a ventral nerve cord and several ganglia
• B. A brain, a dorsal nerve cord and several ganglia
• C. A brain, a dorsal and ventral nerve cord and several ganglia
• D. A ventral nerve cord and several ganglia

Explanation: A highly deyeloped nervous system is present. It consists of paired ganglia (simple brain) connected to a ventral double nerve cord. A ganglion is present in each segment. Nerves arise from these ganglia. The sensory organs are usually a pair of compound eyes and antennae etc.

1026. A sponge of antarctia which is more than a meter tall is known as?

• A. Euplectella
• B. Spongilla
• C. Leucosolenia
• D. Scolymastra joubini

Explanation: Scolymastra joubini is the sponge of antarctica.

1027. Carapace is present in which class of arthropoda?

• A. Arachinds
• B. Insects
• C. Crustaceans
• D. All of these

Explanation: The carapace is the hard, protective outer shell or shield that covers the dorsal part of the cephalothorax in crustaceans, including crabs, lobsters, and shrimp. It serves as a protective exoskeleton for the body and provides support for internal organs. The shape and characteristics of the carapace can vary among different crustacean species, contributing to their diverse forms and functions.

1028. Which of the following is an example of class bivalvia?

• A. Anodonta
• B. Lolgio
• C. Limax
• D. Sepia

Explanation: This class includes bilaterally symmetrical aquatic molluscs. The body is laterally compressed and is enclosed by two pieces of shells hence the name bivalves. They respire by plate-like gills.

1029. The body of which of the following organism is globular?

• A. Cake urchin
• B. Brittle star
• C. A and D
• D. Sea urchin

Explanation: Cake urchin belongs to the phylum echinodermate. Cake urchin possess a bilateral symmetry and is flattened, hence giving a globular shape. This is correct option

1030. Mantle in mollusca is present over which of the following regions?

• A. Head
• B. Dorsal muscular foot
• C. Dorsal visceral foot
• D. Both A and B

Explanation: Mantle is layer of tissues which is present between the shell and the body to protect and hide the visceral body parts. Mantle is present over the dorsal visceral foot.