Free Biodiversity and Variety of Life MCQs with Answers

3011. The larva of balanoglossus (Hemichordate) is called:

• A. Bipinnaria
• B. Radiolaria
• C. Tornaria
• D. Trochophore

Explanation: Balanoglossus is a genus of ocean-dwelling acorn worms (Enteropneusta). Many hemichordates such as acorn worms have a larval stage in their life cycle; the larvae, called tornariae, swim using microscopic hairs called cilia. The tornaria larva resembles the bipinnaria larva of echinoderms.

3012. Which of the following animal is included in deuterostome?

• A. Mytilus
• B. Chaetopterus
• C. Penguin
• D. Jellyfish

Explanation: Deuterostomes are a group of animals characterized by their embryonic development, where the anus forms before the mouth. Penguins, as part of the phylum Chordata, are considered deuterostomes. In contrast, Mytilus and Chaetopterus are classified as protostomes, which develop with the mouth forming first. Jellyfish, from the phylum Cnidaria, do not fit into either category due to their unique body structure and embryonic development.

3013. Porifera is related to the sub Kingdom of:

• A. Protozoa
• B. Parazoa
• C. Metazoa
• D. Aves

Explanation: Porifera, commonly known as sponges, belong to the subkingdom Parazoa within the kingdom Animalia. Parazoa is characterized by simple multicellular organisms that lack true tissues. This distinguishes them from the more complex tissue organization found in the subkingdom Metazoa, which includes most other animals. Protozoa are not part of the animal kingdom and are instead considered protists. Aves, being a class within the subphylum Vertebrata, are not related to the simple structure of Porifera.

3014. The females of one of the following classes possess a single overy, that is:

• A. Pisces
• B. Amphibia
• C. Reptilia
• D. Aves

Explanation: The correct answer is Aves. Female birds generally possess a single ovary on the left side of their body, an adaptation believed to support flight by minimizing body weight. In contrast, the other vertebrate classes listed-Pisces, Amphibia, and Reptilia-usually have two ovaries. This bilateral ovary arrangement is suited to their respective environments and does not have the weight constraints associated with flight.

3015. Chiroptera are:

• A. Flying mammals
• B. Flesh-eating mammals
• C. Hoofed mammals
• D. Aquatic mammals

Explanation: Chiroptera, commonly known as bats, are the only flying mammals. Their wings are composed of a thin membrane of skin supported by elongated finger bones, enabling them to achieve powered flight. This adaptation distinguishes them from other mammals that might glide but cannot sustain flight. The incorrect options include: flesh-eating mammals, which are not an accurate general classification as most bats eat insects or fruits; hoofed mammals, which have hooves unlike the bat's wing structure; and aquatic mammals, which are adapted to life in water, in contrast to the terrestrial and aerial adaptations of bats.

3016. "Portuguese-man of war" is the:

• A. Desert-snake
• B. Coelenterate
• C. A big-reptile
• D. Black-forest monkey

Explanation: The Portuguese-man-of-war is a coelenterate, a marine invertebrate belonging to a group that includes jellyfish and sea anemones. It is a colonial organism composed of specialized polyps that perform different functions such as buoyancy, prey capture, and reproduction. Unlike reptiles, which are vertebrates with scales, or monkeys, which are mammals, the Portuguese-man-of-war is a venomous coelenterate capable of delivering a painful sting. It is not related to desert snakes or any type of mammal.

3017. Amphibians generally have three chambers in their hearts. What type of chambers they are?

• A. One ventricle, two atria
• B. Two ventricles, one atrium
• C. One ventricle, one atrium
• D. One ventricle, one atrium, one sinus venosus

Explanation: Amphibians typically have a heart with three chambers, which includes one ventricle and two atria. This structure allows for some mixing of oxygenated and deoxygenated blood, which is suitable for their metabolism and lifestyle. In contrast, the hearts of birds and mammals have four chambers (two atria and two ventricles) to completely separate oxygenated and deoxygenated blood. The incorrect options either suggest an incorrect number of chambers or misidentify the sinus venosus as a primary chamber.

3018. The study of fishes is:

• A. Ornithology
• B. Ichthyology
• C. Herpetology
• D. Serpetology

Explanation: The correct answer is Ichthyology, which is the scientific study of fishes, including their biology, classification, and conservation. Ornithology refers to the study of birds, Herpetology covers amphibians and reptiles, and 'Serpetology' is not an established scientific term.

3019. Tornaria larva resembles with:

• A. Bipinnaria larva
• B. Trochophore larva
• C. Glochidium larva
• D. Instar larva

Explanation: Tornaria larva resembles with Bipinnaria larva. Because Tornaria larva of hemichordates and Bipinnaria of Echinodermata are very similar in shape and structure. The pattern of cleavage of a fertilised egg, formation of mesoderm, anus, mouth, and coelom in echinoderms and hemichordates is similar. So, most resemblance is with Bipinnaria larva.

3020. Which of the following is not isotonic to sea water?

• A. Myxine (Hagfish)
• B. Skates
• C. Sharks
• D. Teleost (Bony Fishes)

Explanation: Marine teleosts are hypoosmotic to seawater, so they face osmotic loss of water and diffusional gain of NaCl across the gill.