Free Kingdom Animalia MCQs with Answers

401. The animals of division Radiata are which of the following?

• A. Triploblastic
• B. Diploblastic
• C. Radioblast
• D. All of these

Explanation: Characteristics of the radiata is that they are diploblastic. Diploblastic organisms only have two embryonic tissues layers; endoderm and ectoderm.

402. In which phylum, the coelom is formed by fusion of gut pouches during embryonic stage?

• A. Platyhelminthes
• B. Aschelminthes
• C. Annelida
• D. Hemichordata

Explanation: In enterocoelous animals, the coelom is formed from pouches pinched off from the digestive tract which is also known as the embryonic gut or archenteron during the embryonic stage. This type of coelom occurs in deuterostome animals. Hemichordata is a phylum of marine deuterostome animals. So, the correct answer is 'Hemichordata'.

403. An important characteristic that Hemichordates share with Chordates is:

• A. Pharynx without gill slits
• B. Absence of notochord
• C. Ventral tubular nerve cord
• D. Pharynx with gill slits

Explanation: Animal belongs to phylum Chordata is characterized by the presence of the notochord, dorsal hollow nerve cord and pharyngeal gill slits. Hemichordata is the phylum of animals that shows certain similar characters of the Chordata such as the presence of pharyngeal gill slits.

404. Which of the following is an ovoviviparous organism?

• A. Reptiles
• B. Mammals
• C. Frog
• D. Duckbill platypus

Explanation: The Duckbill platypus is a unique mammal that has webbed feet and a body covered with waterproof dense fur. She lays 1 to 3 eggs. She incubates them for 10 days inside her body and then gives them birth.

405. The radial symmetry is found in the animals of which of the following?

• A. Protozoa
• B. Porifera
• C. Cnidaria
• D. All of these

Explanation: 'Radial symmetry' is the arrangement of body parts around a central axis and is only present in grade radiata. 'A' and 'B' are not the answers because both of the classes are primitive and are not diploblastic. Radial symmetry is found in the 'cnidarians' (including jellyfish, sea anemones, and coral) and 'echinoderms' (such as sea urchins, brittle stars, and sea stars).

406. Aquatic arthropods belonging to this class breathe through gills.

• A. Insects
• B. Arachnids
• C. Crustaceans
• D. Arachnids and Crustaceans

Explanation: 'Aquatic arthropods' (crustaceans and the chelicerate horseshoe crabs) possess gills for respiration. Although they vary in structure and location, the gills are always outgrowths of the integument (skin) and are therefore covered by the exoskeleton, which is thin in this area and not a barrier to the exchange of gases.

407. Which of these is a eucoelomate?

• A. Earthworm
• B. Jelly fish
• C. Sycon
• D. Planaria

Explanation: 'Eucoelomates' are those organisms having a body cavity that is a coelom - distinguished from acoelomate and pseudocoelomate. Planaria belongs to the phylum Platyhelminthes which are acoelomates (have no coelom). Sycon is a sponge that has no body arrangement at all (Phylum Porifera) Jellyfish belong to the phylum Cnidaria which is also acoelomates. Earthworms are annelids which are eucoelomates

408. In some cases, the blastomere can produce a complete embryo so, the cleavage will be:

• A. Spiral and determinate
• B. Spiral and indeterminate
• C. Radial and determinate
• D. Radial and indeterminate

Explanation: The answer is Radial and indeterminate. In radial cleavage, the cells divide along a vertical axis, creating a stack of cells. This type of cleavage is indeterminate, meaning that each cell has the potential to develop into a complete embryo. In spiral cleavage, the cells divide along a diagonal axis, creating a spiral pattern of cells. This type of cleavage is determinate, meaning that each cell has a predetermined fate.

409. Which of following systems is segmentally arranged in annelids?

• A. Excretory system
• B. Digestive system
• C. Circulatory system
• D. Nervous system

Explanation: Option C: Annelids have a closed circulatory system, which means the blood circulates through a closed network of blood vessels. In some cases, such as with polychaete worms, the blood is pumped directly through self-contracting blood vessels. In other cases, blood is carried throughout the body from a central pumping organ, like the human heart. Moreover, the circulatory system is segmentally arranged throughout the segmented annelid. Option A: As explained this is an incorrect option. Option B: As explained this is an incorrect option. Option D: As explained above this is an incorrect option.

410. Which animal of the following is a prototherian?

• A. Alligator
• B. Penguin
• C. Porcupine
• D. Spiny anteater

Explanation: 'Spiny anteater', species of Australia, are an example of a 'Prototherian'.