Free Biodiversity and Variety of Life MCQs with Answers

1031. A hydrostatic skeleton is present in

• A. Arthropods
• B. Fishes
• C. Annelids
• D. Nematodes

Explanation: Hydroskeleton or hydrostatic skeleton is a type of internal skeleton in which fluid is kept under constant pressure and that fluid is then used to provide rigidity to the organism. In hydrostatic skeleon, no bone is involved. Hydrostatic skeleton is present in simple invertebrates.

1032. Animals like starfish have small groups of neurons in each arm connected to a ring neurons in the centre. This type of nervous system is called _

• A. Centralized nervous system
• B. Partiallty centralized nervous system
• C. Diffuse nervous system
• D. Partially diffuse nervous system

Explanation: Partially diffused nervous system is that type of primitive nervous sytem which do not have any ganglia present. This type of nervous system is found in starfish. Hence this is the correct answer.

1033. Shark liver oil is source of:

• A. Vitamin B and C
• B. Vitamin D and K
• C. Vitamin A and D
• D. Vitamin E and C

Explanation: It is a fact that shark liver oil is rich in vitamins like vitamin A and vitamin D and vitamin E.

1034. Which class has the largest number of animals?

• A. Fishes
• B. Reptiles
• C. Insects
• D. Mammals

Explanation: This is correct because this class INSECTA constitutes about 40% of the total known species.This class represents arond 1 million species of the world and the phylum to which it belongs, arthropoda , constitutes about 84% of the known species.

1035. Aquatic arthropods respire through which of the following?

• A. Gills
• B. Spiracles
• C. Book lungs
• D. Both A and B

Explanation: Aquatic arthropods, such as crustaceans, respire through gills, which are specialized respiratory organs located in their body. Gills allow them to extract oxygen from the water and release carbon dioxide.

1036. Vertebrates belong to phylum chordata because:

• A. They have a vertebral column
• B. The brain is enclosed by the skull
• C. The embryos have gills
• D. The body develops from three germinal layers

Explanation: Chordates, including vertebrates, undergo embryonic development with three primary germinal layers: ectoderm, mesoderm, and endoderm. These layers give rise to different tissues and organs, enabling the complex body development seen in chordates.

1037. Aquatic arthropods belonging to which of the following class breathe through gills:

• A. Insects
• B. Arachnids
• C. Crustaceans
• D. None of the above

Explanation: Crustacea is a diverse class of arthropods that includes familiar aquatic organisms such as crabs, lobsters, shrimp, and barnacles, as well as some smaller organisms like copepods and krill. One characteristic feature of crustaceans is their respiratory system, which involves the use of gills for breathing.

1038. Salamander belongs to which of the following class?

• A. Pisces
• B. Ayes
• C. Reptiles
• D. Amphibians

Explanation: Amphibia is a class of vertebrates that includes frogs, toads, newts, and salamanders. These animals are adapted to a semi-aquatic lifestyle, as they spend part of their lives in water and part on land. Salamanders are specifically known for their ability to regenerate lost body parts, including limbs and tails.

1039. The best function of coelom is described as:

• A. To increase the size of the animals
• B. To help in the functioning of reproductive system
• C. To provide space for the development of organs and system
• D. All of these

Explanation: The best function of coelom is described as providing a space for the internal organs, allowing them to move and function independently of each other and the body wall

1040. Nervous system of nematodes consists which of the following?

• A. Ventral nerve cord
• B. Dorsal nerve cord
• C. Lateral nerve cord
• D. All of these

Explanation: Nervous system of nematodes consists of dorsal nerve cord, ventral nerve cord and lateral nerve cord.