Biology MCQs

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All the species listed are water-dwelling creatures. However, a fundamental difference is that fish belong to the group of vertebrates, meaning their body possesses a spinal column. In contrast, crabs, prawns, and snails are invertebrates, denoting that they lack a backbone. Specifically, crabs and prawns are crustaceans, within the larger class of invertebrates, characterised by their exoskeleton and segmented bodies. Snails are grouped as molluscs, also a class of invertebrates, known for their soft unsegmented body. Hence, in this context, fish are different from the others.

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Vitamin A, D & C are respectively called as Retinol, Calciferol and Ascorbic Acid. Vitamin A is essential for good vision, a healthy immune system, and cell growth. Vitamin D is a fat-soluble vitamin whereas Vitamin C is a water-soluble vitamin which is found in many foods, particularly fruits and vegetables.

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Polymerase enzyme plays an important role in adding the building blocks to the primer in a sequence determined by the DNA template. It synthesizes long chains of polymers or nucleic acids.

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Liquorice root, or Mulethi, is a potent expectorant that has been utilized in Ayurvedic medicine since ancient times. The powdered root is used in “Jastimadhu” tooth powder. Many cough syrups incorporate Liquorice as one of their components. It is also used to treat mouth and peptic ulcers, attesting to its versatile medicinal properties. Liquorice root is well-regarded for its numerous health benefits apart from its sweet flavour.

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The umbilical cord contains Wharton’s jelly, a gelatinous substance made largely from mucopolysaccharides which protects the blood vessels inside. It contains one vein and two arteries that carries oxygenated and deoxygenated blood respectively.

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Gout is caused by deposition of uric acid crystals in the joint, causing inflammation. There is also an uncommon form of gouty arthritis caused by the formation of rhomboid crystals of calcium pyrophosphate known as pseudogout. In the early stages, the gouty arthritis usually occur in one joint, but with time, it can occur in many joints and be quite crippling. The joints in gout can often become swollen and lose function.

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When we respire, most of the carbon dioxide as bicarbonate ions is transported in the blood. The carbon dioxide dissolved in the blood reacts with water and by the help of zinc containing enzyme called carbonic anhydrase, they form carbonic acid. It immediately dissociates to give H+ and bicarbonate ions once carbonic acid is formed. The haemoglobin present in the erythrocytes (RBCs) combines with the H+ ions immediately. The bicarbonate ion goes into the blood plasma which creates an ionic imbalance between the plasma and the erythrocytes. The chloride ions then diffuse from the blood plasma into the RBCs to maintain the ionic balance. The process of chloride ion diffusing into the erythrocytes to maintain the ionic balance is described as Hamburger’s Phenomenon.

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Cells of the epidermis produce root hairs near the root apex. These cells are generally thin-walled, in contrast to the cells of the cortex, lying below the surface, which ultimately may become very thick-walled. The root hairs have fundamental importance in absorption of water and nutrients.

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Insulin and glucagon are hormones secreted by islet cells within the pancreas. They are both secreted in response to blood sugar levels, but in opposite fashion. Insulin is normally secreted by the beta cells of the pancreas. Glucagon raises blood glucose levels by stimulating the liver to metabolize glycogen into glucose molecules and to release glucose into the blood.  Insulin is a hormone that regulates blood sugar levels.

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The human immunodeficiency virus is a type of virus called a retrovirus. Like all viruses, human immunodeficiency virus reproduces using the genetic machinery of the cell it infects. With the help of an enzyme called integrase (also produced by HIV), the viral DNA becomes integrated with the cell’s DNA.