Free Biodiversity and Variety of Life MCQs with Answers

1381. Polymorphism is a characteristic of members of phylum:

• A. Porifera
• B. Annelida
• C. Cnidaria
• D. Arthropoda

Explanation: Polymorphism is a characteristic found in members of the phylum Cnidaria. Cnidaria is a diverse group of aquatic invertebrates that includes jellyfish, corals, sea anemones, and hydroids. One of the defining features of cnidarians is their possession of specialized stinging cells called cnidocytes, which contain nematocysts used for capturing prey and defense. Polymorphism in cnidarians refers to the existence of different body forms within a single species. Many cnidarians exhibit two or more distinct morphological forms, each specialized for different functions or stages of their life cycle.

1382. Hydra belongs to phylum:

• A. Mollusca
• B. Annelida
• C. Cnidaria
• D. Arthropoda

Explanation: Hydra is a genus of small, freshwater organisms belonging to the phylum Cnidaria. Cnidaria includes a diverse group of aquatic invertebrates that also comprises jellyfish, corals, sea anemones, and hydroids.Hydra are simple, predatory animals with a tubular body and a basal disc that allows them to attach to surfaces in freshwater habitats, such as ponds, lakes, and slow-moving streams. They possess specialized stinging cells called cnidocytes, which are found in their tentacles and are used for capturing and immobilizing prey.

1383. The excretory system of flatworms is composed of:

• A. Nephron
• B. Flame cells
• C. Nephridia
• D. Ganglia

Explanation: The excretory system of flatworms is composed of specialized structures called flame cells, also known as protonephridia. Flame cells are the primary excretory organs in flatworms, and they play a crucial role in removing metabolic waste and excess water from the body.Flame cells are found in the parenchyma (the tissue filling the space between organs) of flatworms. They consist of a tubule with a single flame-shaped cluster of cilia (hair-like structures) at their open end. The beating cilia create a flickering or flame-like appearance, giving these cells their name.

1384. Excretory system in arthropods is composed of:

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

Explanation: The excretory system in arthropods is composed of specialized structures called Malpighian tubules. These tubules are the primary organs responsible for excretion and osmoregulation in arthropods, including insects, spiders, and other related groups. Malpighian tubules are long, slender tubes located in the abdominal region of arthropods, typically near the junction of the midgut and hindgut. These tubules are involved in the removal of metabolic wastes, such as nitrogenous compounds (e.g., ammonia, uric acid), from the hemolymph (the arthropod equivalent of blood).

1385. Animal that have their body cavity filled with parenchyma are:

• A. Acoelomates
• B. Pseudococlomates
• C. Coelomates
• D. Mesoderms

Explanation: Animals that have their body cavity filled with parenchyma are called "acoelomates." Parenchyma refers to the tissue that fills the space between the gut (digestive cavity) and the body wall in acoelomate animals. Unlike coelomates and pseudocoelomates, acoelomates lack a fluid-filled body cavity known as a coelom.

1386. Organ of voice in birds is called as:

• A. Syrinx
• B. Tongue
• C. Larynx
• D. Pharynx

Explanation: The syrinx is the voice box of birds. It is a specialized vocal organ located at the base of a bird's trachea where the trachea splits into the bronchi (the two main branches leading to the lungs). The syrinx is unique to birds and is responsible for producing the sounds and songs that we associate with different bird species. It allows birds to produce a wide variety of complex vocalizations, which they use for communication, attracting mates, establishing territory, and more.

1387. Pseudocoelom develops from which of the following?

• A. Blastopore
• B. Plastoquinone
• C. Splitting of mesoderm
• D. Blastocoel

Explanation: Blastocoel gives rise to pseudocoelom. Pseudocoelom is not homologous to true coelom because: it is not lined by coelomic epithelium. It has no relation with the reproductive and excretory organs. It develops from the blastocoel of the embryo and it is bounded externally by the muscles and internally by the cuticle of the intestine.

1388. Sub-kingdom parazoa includes:

• A. Armada
• B. Cnidaria
• C. Porifera
• D. Protozoa

Explanation: The simplest of the animals belong to subkingdom Parazoa (phylum Porifera). Parazoa includes the simplest multicellular animals, which are sponges (phylum Porifera). These animals lack true tissues and organs but have a cellular level of organization, making them part of Parazoa.

1389. Gut of acoelomates develop from:

• A. Mesoderm
• B. Endoderm
• C. Mesoglea
• D. Ectoderm

Explanation: Option B is correct.The gut of acoelomates develops from the endoderm. The endoderm is the innermost of the three germ layers that form during embryonic development. It gives rise to the lining of the gut, as well as the liver, pancreas, and thyroid gland. Acoelomates are a group of animals that lack a true body cavity. This means that the gut is not surrounded by a layer of tissue called the peritoneum. Instead, the gut is in direct contact with the body wall. There are three main types of acoelomates: platyhelminthes, gastrotrichs, and rotifers

1390. Which is not the characteristic of triploblasts?

• A. They may be coelomate pseudocoelomate or acoelomate
• B. They are included in grade bilateria
• C. All of them have digestive system
• D. All of them have blood vascular system

Explanation: Not all Triploblasts have vascular systems, but all of them have digestive systems, are included in grade bilateria, and may be coelomate pseudocoelomate or acoelomate .