Biology MCQs
31. Cuscuta is a ____:
[A] Complete stem parasite
[B] Partial root parasite
[C] Partial stem parasite
[D] Complete root parasite
[B] Partial root parasite
[C] Partial stem parasite
[D] Complete root parasite
Correct Answer: A [Complete stem parasite]
Notes:
Cuscuta (Dodder) is a genus of about 100-170 species of yellow, orange or red (rarely green) parasitic plants. Dodders are supremely adapted for a life of plunder and pillage. Reduced in form to scrambling and twining threads, they appear to be completely leafless, although closer inspection reveals tiny scale leaves pressed close to the stems. So, it is a stem parasite.
Cuscuta (Dodder) is a genus of about 100-170 species of yellow, orange or red (rarely green) parasitic plants. Dodders are supremely adapted for a life of plunder and pillage. Reduced in form to scrambling and twining threads, they appear to be completely leafless, although closer inspection reveals tiny scale leaves pressed close to the stems. So, it is a stem parasite.
32. Vitamin C is also known as _____:
[A] Tartaric acid
[B] Acetic acid
[C] Ascorbic acid
[D] Malic acid
[B] Acetic acid
[C] Ascorbic acid
[D] Malic acid
Correct Answer: C [Ascorbic acid]
Notes:
Vitamin C is also known as ascorbic acid (C6H8O6). It is a water-soluble vitamin that occurs as a white or slightly yellow crystal or powder with a slight acidic taste. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone.
Vitamin C is also known as ascorbic acid (C6H8O6). It is a water-soluble vitamin that occurs as a white or slightly yellow crystal or powder with a slight acidic taste. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone.
33. Bio-magnification implies ____:
[A] Food is magnified
[B] Living beings are magnified
[C] Light is magnified
[D] Toxic matters are magnified
[B] Living beings are magnified
[C] Light is magnified
[D] Toxic matters are magnified
Correct Answer: D [Toxic matters are magnified]
Notes:
Biomagnification is the sequence of processes in an ecosystem by which higher concentrations of a particular chemical such as the pesticide DDT, are reached in organisms higher up the food chain. It’s principal cause is eutrophication of stagnant water leading to the increase in BOD level. The some biomagnifcation has led to the ban on the use of DDT as a pesticide.
Biomagnification is the sequence of processes in an ecosystem by which higher concentrations of a particular chemical such as the pesticide DDT, are reached in organisms higher up the food chain. It’s principal cause is eutrophication of stagnant water leading to the increase in BOD level. The some biomagnifcation has led to the ban on the use of DDT as a pesticide.
34. Oxygenated blood is carried by _____:
[A] Hepatic portal vein
[B] Renal vein
[C] Pulmonary artery
[D] Pulmonary vein
[B] Renal vein
[C] Pulmonary artery
[D] Pulmonary vein
Correct Answer: D [Pulmonary vein]
Notes:
The pulmonary veins drain oxygenated blood from the lungs to the left atrium. A small amount of blood is also drained from the lungs by the bronchial veins. There are typically four pulmonary veins, two draining each lung. The pulmonary veins are part of the pulmonary circulation.
The pulmonary veins drain oxygenated blood from the lungs to the left atrium. A small amount of blood is also drained from the lungs by the bronchial veins. There are typically four pulmonary veins, two draining each lung. The pulmonary veins are part of the pulmonary circulation.
35. During photosynthesis, green plants use energy from sunlight to synthesize ___ from carbon dioxide and water:
[A] Fructose
[B] Glucose
[C] Sucrose
[D] Galactose
[B] Glucose
[C] Sucrose
[D] Galactose
Correct Answer: B [Glucose]
Notes:
Photosynthesis is the process by which plants, some bacteria and some protistans use the energy from sunlight to produce glucose from carbon dioxide and water. This glucose can be converted into pyruvate which releases adenosine triphosphate (ATP) by cellular respiration. Oxy-gen is released through the stomata on the underside of the leaf; glucose is transported around the plant in the phloem vessels.
Photosynthesis is the process by which plants, some bacteria and some protistans use the energy from sunlight to produce glucose from carbon dioxide and water. This glucose can be converted into pyruvate which releases adenosine triphosphate (ATP) by cellular respiration. Oxy-gen is released through the stomata on the underside of the leaf; glucose is transported around the plant in the phloem vessels.
36. The average life span of red blood corpuscles is about ____:
[A] 100 – 120 days
[B] 100 – 200 days
[C] 160 – 180 days
[D] 150 – 200 days
[B] 100 – 200 days
[C] 160 – 180 days
[D] 150 – 200 days
Correct Answer: A [100 – 120 days]
Notes:
The red blood cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages in liver and spleen (Grave yard of RBC). The old, worn out and dead RBC are destroyed mainly in an organ called spleen.
The red blood cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages in liver and spleen (Grave yard of RBC). The old, worn out and dead RBC are destroyed mainly in an organ called spleen.
37. Which is the effect of antigen in an ill person?
[A] It increases the production of antibiotics
[B] It increases the production of W.B.C.
[C] It increases the production of anti-serum against bacteria
[D] It prevents the growth of bacteria
[B] It increases the production of W.B.C.
[C] It increases the production of anti-serum against bacteria
[D] It prevents the growth of bacteria
Correct Answer: A [It increases the production of antibiotics]
Notes:
Vaccines containing antigens are introduced into the body, stimulating the immune system response by instructing B cells, with assistance from T cells, to produce antibodies. Antibodies are produced to fight the weakened or dead viruses in the vaccine. The immune system prepares to destroy real and stronger viruses in the future. When new antigens enter the body, white blood cells called macrophages engulf them; process the information contained in the antigens, and send it to the T cells to mobilise immune system. Hence, introduction of antigens in any form in body induces the production of antibodies to boost immunity.
Vaccines containing antigens are introduced into the body, stimulating the immune system response by instructing B cells, with assistance from T cells, to produce antibodies. Antibodies are produced to fight the weakened or dead viruses in the vaccine. The immune system prepares to destroy real and stronger viruses in the future. When new antigens enter the body, white blood cells called macrophages engulf them; process the information contained in the antigens, and send it to the T cells to mobilise immune system. Hence, introduction of antigens in any form in body induces the production of antibodies to boost immunity.
38. Which of the following is not correct?
[A] Members of Chlorophyceae are commonly called green algae
[B] Members of Phaeophyceae are commonly called red algae
[C] Members of Rhodophyceae are commonly called red algae
[D] Members of Phaeophyceae are commonly called brown algae
[B] Members of Phaeophyceae are commonly called red algae
[C] Members of Rhodophyceae are commonly called red algae
[D] Members of Phaeophyceae are commonly called brown algae
Correct Answer: B [Members of Phaeophyceae are commonly called red algae]
Notes:
Phaeophyceae is a large group of algae consisting of 240 genera and over 1,500 species out of which 32 genera and 93 species are reported from India. They are commonly known as brown algae, due to the presence of a golden-brown xanthophyll pigment, fucoxanthin (C40H54O6) in the chromatophores.
Phaeophyceae is a large group of algae consisting of 240 genera and over 1,500 species out of which 32 genera and 93 species are reported from India. They are commonly known as brown algae, due to the presence of a golden-brown xanthophyll pigment, fucoxanthin (C40H54O6) in the chromatophores.
39. Conglobate gland is a leaf like structure found in ____:
[A] Male Ascaris
[B] Male Cockroach
[C] Female Cockroach
[D] Female Ascaris
[B] Male Cockroach
[C] Female Cockroach
[D] Female Ascaris
Correct Answer: B [Male Cockroach]
Notes:
Conglobate gland is a leaf like, median, unbranched gland of male cockroach. It lies below the ejaculatory duct and open into the genital pouch close to the male genital aperture.
Conglobate gland is a leaf like, median, unbranched gland of male cockroach. It lies below the ejaculatory duct and open into the genital pouch close to the male genital aperture.
40. The process of preventing the birds from flying is called ____:
[A] Debeaking
[B] Dubbing
[C] Brailing
[D] Pecking
[B] Dubbing
[C] Brailing
[D] Pecking
Correct Answer: C [Brailing]
Notes:
Brailing is the practice of preventing a bird from flying by tying the wing so that it is impossible for the bird to open wings fully and fly. The brail is a clear plastic strap, fastened by rivets, which will be used to restrain his wing. Brailing the birds helps prevent injuries during shipment.
Brailing is the practice of preventing a bird from flying by tying the wing so that it is impossible for the bird to open wings fully and fly. The brail is a clear plastic strap, fastened by rivets, which will be used to restrain his wing. Brailing the birds helps prevent injuries during shipment.
