31. How many layers are present in the human eye?
[A] Three
[B] Four
[C] Two
[D] Nine
Show Answer
Correct Answer: A [Three]
Notes:
The eye has three main layers. These are Fibrous coat or Sclera, Vascular coat or Uveal tract, and Nervous coat or Retina.
32. Which of the following are the innermost layer of the eyeball and the most delicate layer where photoreceptors are located?
[A] Chloroid
[B] Sclera
[C] Cornea
[D] Retina
Show Answer
Correct Answer: D [Retina]
Notes:
The retina is the innermost layer of the eyeball and the most delicate layer where photoreceptors are located. The retina senses light and creates electrical impulses.
33. Contractile fibrils of muscles are called __
[A] Collagen fibres
[B] Neurofibrils
[C]
Elastin
[D] Myofibrils
Show Answer
Correct Answer: D [Myofibrils]
Notes:
Myofibrils are bundles of protein filaments that contain the contractile elements of cardiomyocytes.
34. Which of the following helps to protect the stomach wall from its secretion of hydrochloric acid?
[A] Pepsin
[B] Trypsin
[C] Amylase
[D] Mucus
Show Answer
Correct Answer: D [Mucus]
Notes:
Mucus helps to protect the stomach wall from its secretion of hydrochloric acid.
35. Which of the following gland of the body produces antibodies?
[A] Thymus gland
[B] Thyroid gland
[C] Pineal gland
[D] Adrenal gland
Show Answer
Correct Answer: A [Thymus gland]
Notes:
The thymus gland secretes thymosin, which matures lymphocytes into T-lymphocytes which produces antibodies and thereby increases immunity.
36. Listeriosis is a serious infection caused by __
[A] Listeria pestis
[B] Listeria monocytogenes
[C] Listeria papillomavirus
[D] None of these
Show Answer
Correct Answer: B [Listeria monocytogenes]
Notes:
Listeriosis is a serious infection caused by Listeria monocytogenes. It is caused by eating food contaminated with the bacterium Listeria monocytogenes.
37. Which property is not exhibited by a disease-causing pathogen?
[A] Invasiveness
[B] Toxigenicity
[C] Virulence
[D] Co-operation
Show Answer
Correct Answer: C [Virulence]
Notes:
Cooperation is a property that is not exhibited by pathogens. Whereas The invasion of a pathogen is the ability of a host to gain entry and multiply. A virus is the ability of a pathogen to cause disease. Toxicity is the power of a pathogen to form toxins capable of harming host cells.
38. Some strains of Bacillus thuringiensis can kill certain insects such as __.
[A] Lepidoptera
[B] scorpion
[C] fruit fly
[D] dragonfly
Show Answer
Correct Answer: A [Lepidoptera]
Notes:
Some strains of Bacillus thuringiensis can kill certain insects such as Lepidoptera. They are an order of insects consisting of moths and butterflies.
39. What does Insulin do?
[A] Increases blood sugar
[B] Decreases blood sugar
[C] Constricts blood vessels
[D] Stimulates lactation
Show Answer
Correct Answer: B [Decreases blood sugar]
Notes:
Insulin is central to regulating carbohydrate and fat metabolism in the body. It stops the use of fat as an energy source by inhibiting the release of glucagon. It removes excess glucose from the blood, which otherwise would be toxic. Insulin helps blood sugar enter the body’s cells so it can be used for energy. Insulin also signals the liver to store blood sugar for later use. Blood sugar enters cells, and levels in the bloodstream decrease, signaling insulin to decrease too.
40. Panthera pardus is the scientific name of ____:
[A] Panther
[B] Leopard
[C] Lion
[D] Tiger
Show Answer
Correct Answer: B [Leopard]
Notes:
Panthera pardus is the scientific name of leopard, one of the five “big cats” in the genus Panthera. It is a member of the family Felidae with a wide range in sub-Saharan Africa and parts of Asia. It belongs to the Chordata phylum, Mammalia class and Carnivora order.