Free Biodiversity and Variety of Life MCQs with Answers

2711. All of the following coelenterates show alternation of generation except?

• A. Hydra
• B. Obelia
• C. Aurellia
• D. All of these options are correct

Explanation: Hydra does not show alternation of generation in its life cycle. It also does not have any larval stage during its life cycle.

2712. Which of the following is not a mammal?

• A. Goat
• B. Whale
• C. Shark
• D. Seal

Explanation: Mammals are a group of warm-blooded animals that give birth to their offspring such that the young are fed with milk produced in their mother's mammary glands, have fur or hair on their body, and have enhanced brain functions. Examples: Whales, goats, cows, seals, dogs, etc. The shark is a cartilaginous fish that belongs to the Chondrichthyes class of Pisces.

2713. The name 'Animal' is derived from the word _.

• A. Aname
• B. Anemia
• C. Anima
• D. None of these

Explanation: The word animal comes from the Latin word anima or animalis, meaning 'having breath', 'having soul', or 'living being'. Anaemia is a condition in which you lack enough healthy red blood cells to carry adequate oxygen to your body's tissues so Option B is not correct. Option A is also not correct.

2714. These animals have three germinal layers but no coelom

• A. Flatworms
• B. Roundworms
• C. Cnidarians
• D. Chordates

Explanation: Option A: Flatworms, also known as Platyhelminthes, have three germinal layers (ectoderm, mesoderm, and endoderm) but do not possess a true coelom. They have a solid body structure without a fluid-filled body cavity. Instead, they have a parenchyma, which is a loose tissue that fills the space between organs.Option B: Roundworms, also known as Nematodes, are another group of animals that have three germinal layers but lack a true coelom. They have an inner tube-like digestive tract but lack a fully developed body cavity. Instead, they possess a pseudocoelom, which is a partially lined body cavity.Option C: Cnidarians, such as jellyfish, corals, and sea anemones, have three germinal layers but do not have a coelom. They have a sac-like body plan with a central digestive cavity called the gastrovascular cavity. The gastrovascular cavity serves both as a digestive and circulatory system, but it is not considered a true coelom.Option D: Chordates, which include vertebrates (animals with a backbone) and some invertebrates, have three germinal layers and possess a true coelom. Chordates have a well-developed body cavity that is fully lined by mesoderm. Examples of chordates include mammals, birds, reptiles, amphibians, and fish.

2715. Which combination of class and its description is correct?

• A. Osteichthyes-A bony endoskeleton and gills covered by operculum
• B. Reptilia-Left aortic arch & internal fertilization
• C. Nematoda-Triploblastic & acoelomates
• D. Cephalopods-Dorsal nerve cord & bilateral symmetry

Explanation: Osteichthyes is the class that contains fish with bony endoskeletons and gill slits covered by an operculum.

2716. All of the following are coelomates except:

• A. Deuterostomes
• B. Hemichordates
• C. Proterosomes
• D. Aschelminthes

Explanation: These are the animals having a true body cavity or coelom. The cavity is filled with coelomic fluid. Coelomates are classified as protosomes and deuterostomes. OPTION A: Deuterostomes develop the anus first, then the mouth at the other end of the embryo. Deuterostomes are coelomate animals. OPTION B: All the animals from phylum Annelida to the phylum Chordata are coelomates. OPTION C: Protostomes develop so that the first opening in the embryo is the mouth. Protostomes are bilaterally symmetrical and have three germ layers, the organ level of organization, the tube within-a-tube body plan, and a true coelom. OPTION D: Aschelminthes are called pseudocoelomates. Hence, D is the correct option.

2717. S-band locomotion is characteristically seen in which of the following?

• A. Bony fish
• B. Fish like mammals
• C. Cartilaginous fish
• D. All of these options are correct

Explanation: The S-band is a short wave band that sends out short waves to find any hurdles in the path that are used by cartilaginous fishes for their locomotion. Hence, C is the correct option.

2718. In most triploblastic, after embryonic development, the three layers are represented as?

• A. Separate layers of cells
• B. Structures associated with them
• C. Their functions in body
• D. Structures formed from them

Explanation: Option A is wrong because, in triploblastic animals, the three layers represent the structures formed from them instead of separate layers of the cells. Option B is wrong because, in most triploblastic animals, the three germ layers represent structures formed from them instead of structures associated with them. Option C is wrong because, in most triploblastic animals, the three germ layers represent structures formed from them instead of their functions in the body. Option : D Gastrulation is a key phase in embryonic development when pluripotent stem cells differentiate into three primordial germ layers. It is characterized by movement and rearrangement of cells in the embryo. After embryonic development, in most triploblastic animals, three layers are represented as structures formed from them.

2719. Euplectella belongs to phylum _

• A. Porifera
• B. Ctenophora
• C. Echinodermata
• D. None of the above

Explanation: Euplectella is classified under the phylum Porifera. They belong to the class Hexactinellida, characterized by the skeleton of six-rayed triaxon spicules. The common species of Euplectella is Euplectella aspergillum.

2720. Porcupine is a mammal because:

• A. The scales on its body are modified into spines for protection against predators
• B. It lays eggs and has mammary glands
• C. The fur on its body is modified into spines, and it is warm-blooded
• D. None of the above

Explanation: The following chart might help explain the characteristics of mammals: