Free Cell Structure and Function MCQs with Answers

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

Explanation: The enteron of coelenterates is the gastrovascular cavity, where digestion occurs and through which digested nutrients and materials are…

• A. Few millimeter wide to more than one meter tall
• B. Few centimeter wide to more than one meter tall
• C. Few decimeter wide to more than one meter tall
• D. One meter wide to more than millimeter tall.

Explanation: Sponges show a wide size range, from only a few millimetres in width to species exceeding one metre in height.

• A. Parietal mesoderm
• B. Visceral mesoderm
• C. Mesoderm
• D. Both A & B

Explanation: A coelom is a body cavity completely lined by mesoderm, with parietal mesoderm against the body wall and visceral mesoderm around the…

• A. All animals are ingestive heterotrophs
• B. All animals are eukaryotes
• C. All animals develop from the dissimilar gametes i.e. large sperm and small egg.
• D. It is largest kingdom.

Explanation: Animals develop from dissimilar gametes, but the egg is the large non-motile gamete and the sperm is the small motile gamete, not the…

• A. Nematods
• B. Annelids
• C. Arthropods
• D. Molluscs

Explanation: Annelids are regarded as the first major invertebrate group with a closed circulatory system, in which blood remains within vessels.

• A. Lies on dorsal side
• B. Lies on ventral side
• C. Lies on lateral side
• D. Is not present

Explanation: Arthropods usually have a dorsal tubular heart or main blood vessel that pumps haemolymph forward and backward through the body.

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

Explanation: Arthropoda is the largest animal phylum, and Mollusca is generally considered the second largest in number of described species.

• A. Cake urchin
• B. Sea Urchin
• C. Sea cucumber
• D. Brittle star

Explanation: A sea urchin has a compact, rounded or globular body enclosed by a rigid test and movable spines.

• A. Cyclostomata
• B. Chondrichthyes
• C. Osteichthyes
• D. None of these

Explanation: Cyclostomes, such as lampreys and hagfishes, have long, eel-like bodies and lack paired fins.

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

Explanation: In cephalochordates, such as Amphioxus, the notochord extends from the head region to the tail and remains present throughout life.

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

Explanation: Dipnoi are lungfishes, named for their functional lungs that allow them to breathe atmospheric air, especially when water oxygen is low.

• A. Polyps
• B. Medusae
• C. Both of these
• D. None of these

Explanation: Medusae are the free-swimming, motile zooid form of cnidarians, whereas polyps are generally attached and cylindrical.

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

Explanation: In sponges, sperm released into the water are captured and carried into the mesenchyme or mesohyl, where fertilization occurs.

• A. Detrital organic particles
• B. Zooplankton and small animals
• C. Phytoplanktons
• D. all of these

Explanation: Sponges obtain most of their food by filtering fine detrital organic particles from the water, which are taken up by collar cells and…

• A. Osculum
• B. Ostia
• C. Spongocoel
• D. None of these

Explanation: The osculum is the single main outlet through which water leaves a sponge after passing through its canals and spongocoel.

• A. Amoeboid cell
• B. Stipules
• C. Spicules
• D. Spines

Explanation: Amoeboid cells in the sponge mesohyl capture sperm from the water and transport them to the region containing eggs.

• A. Calcium
• B. Silica
• C. Both of these
• D. None of these

Explanation: Sponge skeletons may contain calcium carbonate spicules or silica spicules, depending on the group, and some also contain spongin fibres.

• A. Peritandrous
• B. Pertandrous
• C. Protendrous
• D. Protandrous

Explanation: Protandrous sponges produce functional sperm before eggs, reducing the chance of self-fertilization and encouraging cross-fertilization.

• A. Scolymastra joubini
• B. Euplectella
• C. Spongilla
• D. Leucoselenia

Explanation: Scolymastra joubini is a giant Antarctic sponge reported to grow more than one metre tall.

• A. To increase the size of the animals
• B. To help in the functioning of reproductive system
• C. To provide space for the development of organs and systems
• D. None of these

Explanation: The coelom provides a fluid-filled space in which internal organs and organ systems can develop, move, and function without being tightly…