Free Biodiversity and Variety of Life MCQs with Answers

• A. Millipede - Ventral Nerve Cord - Arachnida
• B. Sea Anemone - Triploblastic - Cnidaria
• C. Silverfish - Pectoral and Pelvic Fins - Chordata
• D. Duckbilled Platypus - Oviparous - Mammalia

Explanation: The duckbilled platypus is a unique mammal belonging to the order Monotremata within the class Mammalia.

• A. Their gill slits are ventrally placed
• B. Their head and trunk are widened considerably
• C. There is distinct demarcation between body and tail
• D. Their pectoral fins distinctly marked off from cylindrical bodies

Explanation: Sharks and dogfishes have a cylindrical body while skates and rays have both of their pectoral fins fused.

• A. Spiracle in metathorax, trachea, tracheloes, oxygen diffuses into cells
• B. Mouth, bronchial tube, trachea, oxygen enters cells
• C. Spiracles in prothorax, tracheoles, trachea, oxygen diffuses into cells
• D. Hypopharynx, mouth, pharynx, trachea, tissues

Explanation: The respiratory system is well developed in a cockroach in order to compensate the poorly developed circulatory system.

• A. Pila (i) Body segmented Mollusca (ii) Mouth with radula
• B. Asterias (i) Spiny skinned Echinodermata (ii) Water vascular system
• C. Sycon (i) Pore bearing Porifera (ii) Canal system
• D. Periplaneta (i) Jointed appendages Arthropoda (ii) Chitinous exoskeleton

Explanation: Pila belongs to phylum mollusca. The body of molluscs (soft bodied animals) is unsegmented with a distinct head, muscular foot and…

• A. Pteropus and Viviparity - Ornithorhynchus
• B. Garden lizard and crocodile - Three chambered heart
• C. Ascaris and Metameric Ancylostoma - Segmentation
• D. Sea horse and flying fish - Cold blooded (poikilothermal)

Explanation: Sea horse (Hippocampus) and flying fish (Exocoetus) belong to class osteichthyes of super class pisces.

• A. All reptiles possess scales, have a three chambered heart and are cold blooded
• B. All bony fishes have four pairs of gills and an operculum on each side
• C. All sponges are marine and have collared cells
• D. All mammals are viviparous and possess diaphragm for breathing

Explanation: All bony fishes do have four pairs of gills and an operculum on each side of their bodies.

• A. Female Ascaris - sharply curved posterior end
• B. Male frog - a copulatory pad on the first digit of the hind limb
• C. Female cockroach - anal cerci
• D. Male shark - claspers borne on pelvic fins

Explanation: Tail end is straight in female Ascaris, while tail end is curved towards ventral in male Ascaris.

• A. Ascaris (i) Body segmented Annelida (ii) Males and females distinct
• B. Salamandra (i) A tympanum represents ear (ii) Fertilization is external Amphibia
• C. Pteropus (i) Skin possesses Mammalia (ii) Oviparous
• D. None of these

Explanation: None of the options is correct. Ascaris is member of phylum Nematoda, which are round worms. They do not have segmented body.

• A. It is present only in larval tail in ascidian
• B. It is replaced by a vertebral column in adult frog
• C. It is absent throughout life in humans from the very beginning
• D. It is present throughoutlife in Amphioxus

Explanation: Humans are mammals which are chordates. Phylum chordata includes animals which possess a notochord either throughout or during early…

• A. Human males
• B. Human females
• C. Both male and female frogs
• D. Male frogs

Explanation: In male frogs, two ureters act as the urinogenital duct which opens into the cloaca.

• A. Penguin is homeothermic while the remaining three are poikilothermic
• B. Leech is a fresh water form while all others are marine
• C. Spongilla has special collared cells called choanocytes which are not found in the remaining three
• D. All are bilaterally symmetrical

Explanation: Spongilla is a common, widely distributed fresh water sponge belonging to phylum porifera.

• A. Flatworms
• B. Sponges
• C. Cnidarians
• D. None

Explanation: Triploblastic is a condition which describes an animal having a body composed of three embryonic germ layers : the ectoderm, mesoderm and…

• A. Roundworms (Aschelminthes) are pseudocoelomates
• B. Molluses are acoelomates
• C. Insects are pseudocoelomates
• D. Flatworms (Platyhelminthes) are coelomates

Explanation: Roundworms, or Aschelminthes, are indeed pseudocoelomates. They have a body cavity called a pseudocoelom that is partially lined with…

• A. Possess a solid single stranded central nervous system
• B. Lay eggs and guard them till they hatch
• C. Possess bony skeleton
• D. Have gill slits at some stage

Explanation: Animals belonging to Phylum Chordata are fundamentally characterised by the presence of a notochord, a dorsal hollow nerve cord and paired…

• A. Aschelminthes (round worms)
• B. Ctenophores
• C. Sponges
• D. Coelenterates (cnidarians)

Explanation: Aschelminthes is a superphylum consisting of pseudocoelomates. These are mostly aquatic, free living or parasitic.

• A. Coelomic fluid
• B. Haemolymph
• C. Slimy mucus
• D. Excretory fluid

Explanation: Coelom or body cavity of earthworm is filled with coelomic fluid. It lies between body wall and alimentary canal.

• A. Mackerals and rohu
• B. Lampreys and hag fishes
• C. Guppies and hag fishes
• D. Lampreys and eels

Explanation: Agnatha is subphylum or superclass of marine and fresh water vertebrates that lack jaws.

• A. Two special chambers crop and gizzard in their digestive tract
• B. Eggs with a calcareous shell
• C. Scales on their hind limbs
• D. Four chambered heart

Explanation: Yes, both birds and reptiles lay eggs with a calcareous (calcium carbonate) shell, which provides protection and allows for gas exchange…

• A. Presence of true coelom but absence of metamerism
• B. Presence of true coelom and metamerism (metamerisation)
• C. Absence of true coelom but presence of metamerism
• D. Presence of neither true coelom nor metamerism

Explanation: Ascaris belong to the Phylum Nematoda of Superphylum Aschelminthes.They have a cylindrical body without showing any metamerism, a…

• A. Nephridia of earthworm and Malpighian tubules of cockroach - excretory organs
• B. Wings of honey bee and wings of crow - homologous organs
• C. Thorn of Bougainvillea and tendrils of Cucurbita - analogous organs
• D. Nictitating membrane and blind spot in human eye - vestigial organs

Explanation: Nephridia are excretory organs of the earthworm which consist of a simple or branched tube formed by the ingrowth of ectoderm with cilia…