31. Where is heparin derived from?
[A] intestines of pigs
[B] intestines of goats
[C] intestines of cows
[D] intestines of dogs
Show Answer
Correct Answer: A [intestines of pigs]
Notes:
Heparin comes from the intestines of pigs that are slaughtered for meat. Heparin is an important anticoagulant.
32. The reflex actions that involve the brain are called which of the following?
[A] Stimulus
[B] Cerebral reflexes
[C] Spinal reflexes
[D] Reflex arc
Show Answer
Correct Answer: B [Cerebral reflexes]
Notes:
The reflex actions that involve the brain are called Cerebral reflexes. Cerebral reflexes are those reflexes that involve the brain, which is the process of thinking.
33. Photoreceptors in the eye called rods are important for __
[A] Night vision and central vision
[B] Colour vision and peripheral vision
[C] Night vision and peripheral vision
[D] Colour vision and central vision
Show Answer
Correct Answer: C [Night vision and peripheral vision]
Notes:
Photoreceptors in the eye called rods are important for Night vision and peripheral vision. There are about 120 million photoreceptors in our eyes called rods. These are important for scotopic vision or monochromatic vision in low light.
34. Apart from the brain, what does the skull protect?
[A] the lungs
[B] the diaphragm
[C] the body’s cells
[D] the sense organs
Show Answer
Correct Answer: D [the sense organs]
Notes:
The skull, or cranium, also protects the eyes, nose, ears and mouth. There are holes in the skull that allow these senses to pick up light, sound and smell.
35. Which of the following are also called natural killer cells?
[A] Monocytes
[B] Thrombocytes
[C] Lymphocytes
[D] Neutrophils
Show Answer
Correct Answer: C [Lymphocytes]
Notes:
Lymphocytes are also called natural killer cells and play a vital role in producing antibodies. Lymphocytes are of two types – B lymphocytes and T lymphocytes.
36. Which of the following are the benefits of vermicomposting?
[A] develops roots of the plants
[B] increases the fertility and water-resistance of the soil
[C] Both 1 and 2
[D] Neither 1 nor 2
Show Answer
Correct Answer: C [Both 1 and 2]
Notes:
The benefits of vermicomposting are to develop roots of the plants, improve the physical structure of the soil, and increase the fertility and water-resistance of the soil.
37. Symbiotic Bacteria responsible for the fixation of atmospheric nitrogen are present in ____:
[A] Peas
[B] Oats
[C] Corn
[D] Wheat
Show Answer
Correct Answer: A [Peas]
Notes:
Nitrogen-fixing bacteria are microorganisms capable of transforming atmospheric nitrogen into fixed nitrogen. Rhizobium is one such bacteria that is associated with leguminous plants (e.g., various members of the pea family). It invades the root hairs of host plants and convert free nitrogen to ammonia, which the host plant utilizes for its development.
38. A molecule in plants comparable to haemoglobin in animals is ____:
[A] Carotene
[B] Chlorophyll
[C] Cellulose
[D] Cytochrome
Show Answer
Correct Answer: B [Chlorophyll]
Notes:
Haemoglobin is the iron-containing oxygen transporting metalloprotein in the red blood cells of all vertebrates. Similarly, Cytochromes are, in general, membrane-bound haemo-proteins containing heme groups and are primarily responsible for the generation of ATP via electron transport.
39. People with Downs syndrome invariably affected by _____:
[A] Alzheimers disease
[B] Huntingtons disease
[C] Brain haemorrhage
[D] Meningitis
Show Answer
Correct Answer: A [Alzheimers disease]
Notes:
The best-known and most common chromosome abnormality in humans is Down’s syndrome, (Trisomy of 21st pair of chromosome). Down’s syndrome individuals also almost invariably develop Alzheimer’s disease, a form of dementia that is fairly common among the elderly people. People with Down’s syndrome develop this disease in their fourth or fifth decade of life, much sooner than other people. These people are also characterized by presence of webbed neck, Plamers crease, very broad forehead, round face and forked tongue.
40. The optimum dissolved oxygen level (in mg/litre) required for survival of aquatic organisms is ____:
[A] 2 – 4
[B] 4 – 6
[C] 8 – 10
[D] 12 – 16
Show Answer
Correct Answer: B [4 – 6]
Notes:
Oxygen is one of several dissolved gases important to aquatic systems. Dissolved oxygen is necessary to maintain aerobic conditions in surface waters and is considered a primary indicator when assessing the suitability of surface waters to support aquatic life. Dissolved oxygen can be measured in two ways: either in milligrams per litre (mg/L) or percent saturation (% sat). Water with an oxygen concentration of less than 3 mg/L will generally not support fish. When concentrations fall to about 3-4 mg/L, fish start gasping for air at the surface or huddle around the water fall (higher concentration points). Above 5 mg/L, almost all aquatic organisms can survive indefinitely, provided other environmental parameters are present within allowable limits.
