31. Which of the following cells is involved in cell-mediated immunity?
[A] T-cells
[B] B-cells
[C] Mast cells
[D] Both T and B cells
Show Answer
Correct Answer: A [T-cells]
Notes:
T-cells are involved in cell-mediated immunity. T cells are produced in the bone marrow and mature in the thymus.
32. Which of the following is a highly contagious viral disease of cattle?
[A] foot and mouth disease
[B] rinderpest
[C] smallpox
[D] Ranikhet
Show Answer
Correct Answer: B [rinderpest]
Notes:
Rinderpest is a highly contagious viral disease of cattle. Rinderpest is an ancient plague of cattle and other large ruminants. It belongs to the Paramyxoviridae family.
33. Which of the following are examples of hydrophilic molecules?
[A] sugar
[B] cellulose
[C] starch
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
A molecule whose interaction with water and other polar substances is more thermodynamically favorable than its interaction with oil or other hydrophobic solvents is called a hydrophilic molecule. Sugar, salt, starch, and cellulose are examples of hydrophilic molecules.
34. The Bacille Calmette-Guerin vaccine (popularly called BCG vaccine) is a vaccine to prevent which of these diseases?
[A] Polio
[B] Jaundice
[C] Tuberculosis
[D] Typhoid
Show Answer
Correct Answer: C [Tuberculosis]
Notes:
The Bacillus Calmette–Guérin (BCG) vaccine is used to prevent tuberculosis (TB). The BCG vaccine is named after Dr Albert Calmette and Dr Camille Guerin, who developed the vaccine from a germ called Mycobacterium bovis, which is similar to TB. BCG is a live vaccine that has been processed so that it is not harmful to humans. Tuberculosis is an infectious disease caused by bacteria that affects the lungs, and sometimes other parts of the body.
35. Which of the following statement is incorrect?
[A] Budding is not possible in hydra
[B] Hydra have only a sexual reproduction
[C] Most frogs are an oviparous animals
[D] Internal fertilisation takes place in hens
Show Answer
Correct Answer: B [Hydra have only a sexual reproduction]
Notes:
Hydra is radially symmetrical, that is, the parts of its body are arranged in a circle around a central median axis passing through the mouth. Hydra reproduces by asexual and sexual methods. Asexual reproduction takes place either by budding or by fission.
36. Which chromosomal combination is responsible for maleness in man?
[A] XO
[B] XXX
[C] XX
[D] XY
Show Answer
Correct Answer: D [XY]
Notes:
The chromosomes which determine the sex (maleness or femaleness) of an individual in sexually producing organisms are called sex chromosomes or allosomes. In humans an individual whose cells contain XX chromosomes (homo or isogametic) becomes a female, while one whose cells contains XY chromosomes (heterogametic) becomes a male.
37. How many canine teeth does an adult human have?
[A] 8
[B] 4
[C] 3
[D] 2
Show Answer
Correct Answer: B [4]
Notes:
A normal adult mouth has 32 teeth, which (except for wisdom teeth) have erupted by about age 13. The canines are situated at the ‘corners’ of the dental arches. They have a sharp, pointed biting surface. Their function is to grip and tear food. There are four canine teeth in both primary and permanent dentitions.
38. Organisms use bio-catalyst to break down complex substances into simpler substances. These bio–catalysts are called ____:
[A] Enzymes
[B] Vitamins
[C] Hormones
[D] None of the above
Show Answer
Correct Answer: A [Enzymes]
Notes:
Enzymes are sometimes called biological catalysts because they speed up reactions, and only small amounts are required. Digestive enzymes speed up the breakdown of complex food substances into simpler subunits. The breakdown of food in digestion is actually caused by water chemically splitting the complex food molecules, a process called hydrolysis.
39. Which cells in pancreas produce Insulin?
[A] Estrogen
[B] Corpus epididymis
[C] Thymus
[D] Islets of Langerhans
Show Answer
Correct Answer: D [Islets of Langerhans]
Notes:
The islets of Langerhans are the regions of the pancreas that contain cells that produce hormones. There are five types of cells in the islets of Langerhans: beta cells secrete insulin; alpha cells secrete glucagon; PP cells secrete pancreatic polypeptide; delta cells secrete somatostatin; and epsilon cells secrete ghrelin.
40. Which of the following represents a dicot seed?
[A] Rice
[B] Wheat
[C] Pulses
[D] Maize
Show Answer
Correct Answer: C [Pulses]
Notes:
Pulses come under the category of dicot seeds as they contain two cotyledons, hence the term ‘dicotyledon’ where ‘di’ symbolizes two. These seeds house two seedlings within their seed coat. Furthermore, the legume plant family, composed of various types of pulses, beans, peas, and lentils, are common instances of dicot seeds.