Free Biodiversity and Variety of Life MCQs with Answers

1281. Incomplete double circulation is found in:

• A. Aves
• B. Fishes
• C. Amphibians
• D. Mammals

Explanation: Amphibians have a three-chambered heart comprising two atria and one ventricle. Oxygenated and deoxygenated blood received in the left and right atrium, respectively, gets mixed in the single ventricle, hence it is termed as incomplete double circulation.

1282. An invertebrate is found in a freshwater setting and studies show it to have three developmental body layers and a cuticle covering its outer body. It belongs in the same phylum as the

• A. Nematoda
• B. Leeches
• C. Sponges
• D. Sea stars
• E. Crustaceans

Explanation: A majority of crustaceans' habitats are aquatic and they live in either marine or freshwater environments, but a few groups have adapted to life on land, such as terrestrial crabs, terrestrial hermit crabs, and marine environments. Germ layers: each of the three layers of cells (ectoderm, mesoderm, and endoderm) that are formed in the early embryo. they have an cuticle covering so this is correct answer.

1283. Platyhelminthes means:

• A. Flatworms
• B. Roundworms
• C. Segmented worms
• D. None of the above

Explanation: Flatworms are known as Platyhelminthes. Free-living flatworms are mostly predators, and live in water or in shaded, humid terrestrial environments, such as leaf litter.

1284. What is an example of an oviparous animal?

• A. Penguin
• B. Bat
• C. Whales
• D. Elephant

Explanation: Penguins are oviparous, which means they lay eggs. Penguins lay eggs and incubating them. After mating, the female penguin lays one or two eggs, depending on the species, and then both the male and female take turns incubating the eggs by sitting on them to keep them warm. Once the eggs hatch, the parents continue to care for the chicks until they are ready to survive on their own. Whales, Bats and Elephants all reproduce sexually.

1285. All of the following are coelomates except which?

• A. Deuterostomes
• B. Hemichordates
• C. Proterostomes
• D. Platyhelminthes

Explanation: Coelomates are animals that have a true coelom - a fluid-filled body cavity completely lined with mesoderm. Platyhelminthes (flatworms) are acoelomates, meaning they lack a true coelom. The others - deuterostomes, hemichordates, and protostomes - are all groups that include coelomate animals: Deuterostomes include chordates and echinoderms (true coelomates). Hemichordates are marine animals with a true coelom. Protostomes include arthropods, mollusks, and annelids, all of which are coelomates.

1286. Ascarisis characterized by which of the following?

• A. Presence of true coelom and metamerism
• B. Absence of true coelom and metamerism
• C. Presence of true coelom but the absence of metamerism
• D. Absence of true coelom but presence of metamerism, is also incorrect because Ascaris lacks metamerism as well.

Explanation: Ascaris does not have a true coelom. Ascaris is an example of a pseudocoelomate organism. It possesses a pseudocoelom, which is a body cavity that is not entirely lined by mesoderm. This is in contrast to true coelomates, where the body cavity is completely lined by mesoderm.

1287. Which of the following invertebrate phyla consists of the most abundant species on planet Earth:

• A. Porifera
• B. Cnidaria
• C. Arthropoda
• D. Mollusca

Explanation: It is correct as Arthropoda is the phylum of animals that includes insects, spiders, crustaceans, and many other types of animals. Arthropods are the most abundant group of animals on Earth, with more than a million described species .Insects, which come under the phylum Arthropoda, form the most abundant group in the Animal Kingdom. In fact, almost 60% of the animals known today are insect species. This is a ptb line it is mentioned in arthopoda phylum

1288. Which among the following lacks a nervous system

• A. Flat worms
• B. Annelida
• C. Cnidaria
• D. Sponge

Explanation: Sponges are the only multicellular animals without a nervous system. They do not have any nerve cells or sensory cells. However, touch or pressure to the outside of a sponge will cause a local contraction of its body.

1289. Evolutionary progress towards the formation of organ systems in cnidarians includes the development of the enteron and:

• A. Rudimentary network of nerves
• B. Symmetry
• C. Cnidocytes
• D. Cellular organization

Explanation: The development of an enteron and a rudimentary network of nerves in cnidarians is the first evolutionary step towards formation of the organ system. Hence, option A is correct

1290. Earthworm is an example of:

• A. Detritivores
• B. Fluid feeder
• C. Macrophagous
• D. Microphagous

Explanation: Earthworms are detritivores because they primarily feed on dead organic matter. They consume this detritus and break it down into nutrient-rich castings through their digestive processes. Hence, option A is correct.