Free Kingdom Animalia MCQs with Answers

801. What is correct about triploblastic animals?

• A. They show bilateral symmetry
• B. They show both radial and bilateral symmetry
• C. They are all protostomes
• D. They are all deuterostomes

Explanation: Triploblastic animals are characterized by having three primary germ layers: ectoderm, mesoderm, and endoderm. These animals predominantly exhibit bilateral symmetry, which is a common feature across this group. However, there are exceptions, such as adult echinoderms, which show radial symmetry. The statement that triploblastic animals are all protostomes or all deuterostomes is incorrect, as the group includes both types of developmental patterns. Therefore, none of the provided options fully capture the characteristics of all triploblastic animals.

802. From the following statements select the wrong one:

• A. Prawn has one pairs of antennae
• B. Nematocysts are characteristics of the phylum cnidaria
• C. Millepedes have two pairs of appendages in each segment of the body
• D. Animals belonging to phylum porifera are marine and fresh water

Explanation: Prawns have two pairs of antennae, one on either side, just below the antennules. They are sensory, excretory, and balancing in function. Antennules are attached on either side, below the bases of the eye stalks. They are tactile in function. Nematocysts are present in cnidoblasts and act as organs of offence and defence. Millipedes belong to the class Myriapoda. They are called thousand-leggers because they possess numerous walking legs. Their body is made up of a small head and 40 trunk segments, each with two pairs of jointed legs. Animals belonging to the phylum Porifera are mostly marine, while a few are freshwater.

803. The ostrich, penguin and kiwi are _ .

• A. Running birds
• B. Migratory birds
• C. Flightless birds
• D. Four-toed birds

Explanation: The ostrich, penguin, and kiwi are all flightless birds. This category best captures their shared trait of being unable to fly, though they have adapted to different environments: the ostrich to running on land, the penguin to swimming in water, and the kiwi to foraging on the ground. Other options are incorrect because they either apply to only one of the birds or are not characteristic of any of them.

804. All are correct about acoelomates except:

• A. Sac type digestive system
• B. Well-developed respiratory system
• C. Parenchyma fills the body space
• D. Well-developed excretory system

Explanation: The correct answer is Option B: Well-developed respiratory system. Acoelomates, such as those in Phylum Platyhelminthes, lack a well-developed respiratory system and rely on diffusion through their body surface for gas exchange. Option A is incorrect because acoelomates have a sac-like digestive system. Option C is incorrect as the body cavity of acoelomates is filled with parenchyma. Option D is incorrect because their excretory system is simple, consisting of structures like protonephridia, rather than being well-developed.

805. A fluid filled cavity which is mesodermal in origin but absent in nematodes is:

• A. Coelom
• B. Gastrocoel
• C. Pseudocoelom
• D. Spongocoel

Explanation: The coelom is a true body cavity that is entirely lined by mesodermal tissue, providing space for the development and suspension of organs. Nematodes, however, are classified as pseudocoelomates, meaning their body cavity is not completely lined by mesoderm. This distinguishes them from coelomates, which have a fully mesoderm-lined cavity. Other options like the gastrocoel and spongocoel refer to different types of cavities unrelated to the mesodermal origin, while the pseudocoelom, although a body cavity, lacks a complete mesodermal lining and is present in nematodes.

806. Spiral and determinate type cleavage is present in:

• A. Pinworm
• B. Starfish
• C. Cake urchin
• D. Amphioxus

Explanation: Spiral and determinate cleavage is a feature of protostomes, a group that includes organisms such as annelids, mollusks, and nematodes. Pinworms, being nematodes, fall into this category and exhibit this type of embryonic development. In contrast, starfish, cake urchins, and amphioxus are deuterostomes, which are characterized by radial and indeterminate cleavage. This fundamental difference in early developmental stages is key to differentiating between these two major groups of animals.

807. It is not true for Phylum Platyhelminthes:

• A. Bilaterally symmetrical
• B. Triploblastic metazoan
• C. Dorsoventrally compressed body
• D. Radially symmetrical body

Explanation: The correct answer is 'Radially symmetrical body'. Phylum Platyhelminthes is characterized by bilateral symmetry, meaning there is only one plane of symmetry that divides the body into left and right halves. In contrast, radial symmetry, which is incorrect for this phylum, involves multiple planes of symmetry that pass through a central axis, as seen in organisms like cnidarians. Additionally, Platyhelminthes are triploblastic metazoans with a dorsoventrally compressed body, which further distinguishes them from radially symmetrical organisms.

808. Platyhelminthes means:

• A. Flat worms
• B. Roundworms
• C. Segmented worms
• D. None

Explanation: Word Platyhelminthes (derived from the Greek platy, meaning "flat" while helminth meaning "worm") are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates.

809. In_both ovaries and oviducts are functional.

• A. Robin
• B. Kestrel
• C. Eagle
• D. Kiwi

Explanation: The kiwi is the best-known example of a bird in which both ovaries are functional.Kiwis are primitive, flightless birds (ratites), and they retain this ancestral condition.

810. Proglottids are present in:

• A. Dugesia
• B. Schistostoma
• C. Fasciola
• D. Taenia

Explanation: Taenia: Has proglottids. Taenia is a type of tapeworm, and proglottids are segments of its body containing reproductive organs.