Free Biodiversity and Variety of Life MCQs with Answers

• 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.

• 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.

• 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.

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

Explanation: Explanation for this question will be added soon.

• 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…

• 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…

• 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…

• 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.

• 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…

• 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.

• A. Ectoderm
• B. Endoderm
• C. Uterus
• D. Mesenchyme

Explanation: Choanocytes are cells of the mesenchyme, so fertilization occurs there.

• A. Trout
• B. Sea horse
• C. Shark
• D. Tuna

Explanation: Sharks have skeleton made of cartilage and thus are not called "bony" fish. It is part of the chondrichthyes class of fishes.

• A. Duckbill platypus
• B. Spiny anteater
• C. Wolves
• D. Both A and B

Explanation: Monotremes are group of animals that lay eggs, and thus act as connecting feature between both mammals and reptiles.

• A. Perch
• B. Plaice
• C. Catfish
• D. Dogfish

Explanation: Dogfish is included in Chondrichthyes; it has a cartilaginous skeleton.

• A. Obelia
• B. Jellyfish
• C. Hydra
• D. Sea anemone

Explanation: Option C is correct since hydra only exhibits asexual reproduction by budding.

• A. Lamprey
• B. Perch
• C. Plaice
• D. Dipnoi

Explanation: Option D is correct since the group, Dipnoi owes its name from the presence of two internal nostrils.

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

Explanation: If a blastomere is capable of producing a complete embryo, then the cleavage would be considered indeterminate.

• A. Nephridia
• B. Flame cells
• C. Malpighian tubules
• D. Nephrons

Explanation: Platyhelminthes, also known as flatworms, do not have a true excretory system with specialized cells.

• A. Digestive cavity
• B. Body cavity
• C. Transporting cavity
• D. All of these

Explanation: The enteron is the space which acts as the body cavity for all general functions.

• A. Obelia
• B. Jelly fish
• C. Hydra
• D. Sea anemone

Explanation: Alteration of generation refers to the alteration between the methods of reproduction, from sexual to asexual.