Free Biodiversity and Variety of Life MCQs with Answers

1221. Gut in pseudocoelomates is made from which of the following?

• A. Ectoderm
• B. Mesoderm
• C. Endoderm
• D. All of these

Explanation: The pseudocoelom in animals is derived from the blastocoel, which is the primary body cavity formed during embryonic development. The pseudocoelom is a fluid-filled cavity located between the mesoderm and endoderm germ layers. Unlike a true coelom, which is completely lined by mesoderm, the pseudocoelom is only partially lined by mesoderm. This distinction in embryonic development is important in understanding the classification of animals into coelomate, pseudocoelomate, and acoelomate categories.

1222. The animals in which coelom is formed due to the splitting of the mesoderm are known as which of the following?

• A. Pseudocoelom
• B. Enterocoelous
• C. Amphicoelous
• D. Schizocoelous

Explanation: Option D is correct since in Schizocoelus organisms, coelom develops by splitting of the mesodermal embryonic tissue. Option A is incorrect because Pseudocoelom is one of the three types of Coelom not originated by the mesodermal epithelium. Option B is incorrect because, in Enteroceolus organisms, the coelom is formed by the pouches formed by the digestive tract. Option C is incorrect because Amphicoelous is a term used for vertebrae of certain fishes which is concave on both sides.

1223. Octopus belongs to Phylum mollusca because _.

• A. It has suckers and tentacles
• B. It has a soft body covered by a shell
• C. A shell, A muscular foot, And a mantle
• D. It has a soft, Segmented body with a head and a foot

Explanation: Like their clam and snail relatives, cephalopods possess typical molluscan features: a shell, a muscular foot, and a mantle. They also have highly developed sensory organs.

1224. Which is the largest cell in the human body?

• A. Macrophage
• B. Ovum
• C. Granule cell
• D. None of these

Explanation: Explanation for this question will be added soon.

1225. Which statement correctly identifies an adaptation for the parasitic lifestyle of tapeworm?

• A. Presence of suckers and hooks
• B. Asexual reproduction by fission
• C. The presence of mesoderm in embryonic stages
• D. All of the above options are correct

Explanation: Option A is correct since it is the best answer. Tapeworms are acoelomates that have mesoderm divided by fission but the question asks about the adaptation and Options B and C are not adaptations. Another adaptation would be the degradation of the digestive system in tapeworm.

1226. Reptiles are different from amphibians because:

• A. They do not have an amniotic sac in their lungs
• B. They breathe through their lungs only
• C. They are cold-blooded
• D. They have a four-chambered heart

Explanation: Reptiles breathe through their lungs as they have adapted to live completely dry, on land whereas amphibians breathe through their lungs, gills and skin. neither of them have amniotic sacs in their lungs both reptiles and amphibians are cold blooded Reptile hearts have three chambers, two atria and one ventricle. The exception is crocodilians, which have four-chambered hearts.

1227. Notochord is present throughout life in which of the following?

• A. Urochordates
• B. Chordates
• C. Vertebrates
• D. Cephalochordates

Explanation: All animals belonging to Phylum Chordata have three things in common which are as followed: 1: Notochord 2: A dorsal hollow nerve cord 3: Pharyngeal Gill Slits. The question deals with knowing the animal in which notochord persists through out life. Since, Notochord is replaced by Vertebral Column in higher animals thus, option 'B' and 'C' are eliminated immediately. Option A: It deals with Urochordates which contain Notochord in the small region of it's tail, which is consumed ultimately after a time, thus marking it incorrect. Option D: Cephalochordates have a Notochord which extends right in the mid of the dorsal line from anterior to posterior part of the body. In Cephalochordates, Notochord isn't replaced by vertebral column, and thus this is the correct option.

1228. How are flatworms similar to roundworms?

• A. They are both acoelomates
• B. They are both triploblastic
• C. They both show bilateral symmetry
• D. They are both worms
• E. Options B, C and D are correct

Explanation: Flatworms belong to the phylum Platyhelminthes while roundworms belong to the phylum Nematoda. The main difference between flatworms and roundworms is that flatworms consist of a dorso-ventrally flattened body whereas roundworms consist of a cylindrical body tapered to a fine point at each end. Both the worms are bilaterally symmetrical. Bilateral Symmetry is in which similar anatomical parts are arranged on opposite sides of a median axis so, one and only one plane can divide the individual into essentially identical halves. That is the only similarity, they bear. An acoelomate is an animal that has no internal, fluid-filled body cavity separating its body wall from its digestive tract. Moreover, both are triploblastic, i.e. they have three germ layers. that

1229. Mytilus and Anodonta are example of which type of Molluscs?

• A. Gastropods
• B. Bivalves
• C. Cephalopods
• D. None of the above

Explanation: Option B is correct as both have an external covering that is a two-part hinged shell that contains a soft body which is characteristic to "bivalves".

1230. The pores through which water enters the sponge body are called:

• A. Osculum
• B. Ostia
• C. Operculum
• D. None of the above

Explanation: Ostia are small openings or pores in the body wall of certain animals, commonly found in sponges. In the context of anatomy, they are openings through which water enters the sponge, allowing for filter feeding and other essential processes.