Free Biodiversity and Variety of Life MCQs with Answers

1101. The mammals termed as the connecting link between reptilians and mammals are:

• A. Marsupials
• B. Eutherians
• C. Monotremes
• D. Metatherians

Explanation: The monotremes are a group of highly specialised egg-laying predatory mammals, containing the platypus. Platypus is known as connecting link between reptiles and mammals as it has both the characters of mammals and reptiles. It has mammalian characters such as hair, mammary glands, diaphragm. It is oviparous and lays eggs like reptiles.

1102. Bipinnaria is the larval form of:

• A. Coelenterate
• B. Potychaeta
• C. Echinodermata
• D. Cestoda

Explanation: Bipinnaria larva is the larva of class Asteroidea of phylum Echinodermata. It possesses 5 pairs of ciliated arms, which do not have any skeletal support inside. These arms are used for swimming in water, while feeding on planktons. Preoral and postoral ciliary bands are also present. Hence, option C is correct.

1103. Which one of the following coelenterate is also called the Portuguese man of war?

• A. Hydra
• B. Velella
• C. Obelia
• D. Physalis

Explanation: The correct option is Physalis. The Portuguese man o' war is not a single organism but a colonial organism known as Physalia physalis, commonly referred to as the Portuguese man o' war. It belongs to the phylum Cnidaria, which includes coelenterates. Let's briefly discuss the other options as well: Hydra: Hydras are small, freshwater coelenterates belonging to the genus Hydra. They are solitary organisms and are not commonly associated with the name "Portuguese man o' war." Velella: Velella, also known as "by-the-wind sailors" or "sea raft," are oceanic coelenterates. They are free-floating colonies of specialized individuals and have a sail-like structure that allows them to drift on the surface of the water. Although they share some similarities with the Portuguese man o' war in terms of their floating nature, they are distinct organisms. Obelia: Obelia is a genus of hydrozoans, which are coelenterates that are typically found in marine environments. They form branching colonies and have both polyps and medusae in their life cycle. Obelia species are not commonly referred to as Portuguese man o' war. To summarize, Physalis, specifically Physalia physalis, is the correct option for the coelenterate that is commonly known as the Portuguese man o' war.

1104. Pseudo coelomate animals are:

• A. Coelenterates
• B. Nematodes
• C. Annelids
• D. None of them

Explanation: Pseudocoelomates do not have a true coelom (i.e. a cavity that is present between the gut and body wall, and is lined by the mesoderm on both sides). Phylum Nematoda contains pseudocoelomate animals.

1105. Opposable thumbs are characteristic features of

• A. Lagomorpha
• B. Primates
• C. Ederitate
• D. None of these

Explanation: Opposable thumbs allow the digits to grasp and handle objects and are characteristic of primates.

1106. Flame cells are commonly found in:

• A. Platyhelminthes
• B. Annelida
• C. Coelenterate
• D. All of above

Explanation: A flame cell is a specialized excretory cell found in the simplest freshwater invertebrates, including Platyhelminthes. Flame cells function like a kidney and remove waste materials. Bundles of flame cells are called protonephridia. Flame cells function on the basis of filtration & resorption. So, option B is correct.

1107. Sea horse is included in:

• A. Pisces
• B. Mammals
• C. Insects
• D. Mollusca
• E. None of them

Explanation: Seahorses belong to the phylum Pisces. They are tiny fishes named for shape of their head, which looks like the head of a horse. (This question is also basic factual recall)

1108. Despite the structural diversities, _ are characterized by having a soft body protected by a calcareous shell developing from the mantle layer.

• A. Corals
• B. Foraminiferans
• C. Molluscs
• D. None of these

Explanation: The mollusc (or mollusk) shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts.

1109. Which organism has wings with claws?

• A. Eagle
• B. Kestrel
• C. Archaeopteryx
• D. Mallard

Explanation: Unlike a modern bird, Archaeopteryx had toothed jaws, claws on its wings, and a long, bony tail. Use the image below to help retain:

1110. Scales are present in:

• A. Fishes
• B. Reptiles
• C. Birds
• D. Amphibians
• E. A and B

Explanation: The skin of most fishes is covered with scales. Placoid scales in sharks and rays, cosmoid scales in lungfishes and some fossil fishes, ganoid scales in bichirs, bowfin, paddle fishes, gars, sturgeons, cycloid and ctenoid scales in most bony fishes. Reptile skin is also covered with scutes or scales. Scales are made of keratin and are formed from the epidermis. They may be ossified or tubercular, as in the case of lizards, or modified elaborately, as in the case of snakes.