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Q:

Sleeping sickness in man is caused by the organism

A) plasmodium B) entamoeba
C) giardia D) trypanosoma
 
Answer & Explanation Answer: D) trypanosoma

Explanation:

Trypanosoma is a protozoan animal. It lives as a parasite in the blood and later invades the cerebrospinal fluid to cause the sleeping sickness. This parasite is transmitted by the Tsetse fly.

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Filed Under: Biology

Q:

Damage to hearing is caused by sounds which exceed

A) 70 decibles B) 80 decibles
C) 100 decibles D) 120 decibles
 
Answer & Explanation Answer: D) 120 decibles

Explanation:

High frequency sound attacks the tympanic memberane and makes it defective. 120 decibles is too high a pitch to be heard and therefore it impairs the hearing ability.

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Filed Under: Biology

Q:

AIDS is caused by the organisms which are

A) bacteria B) fungi
C) viruses (HTLV III) D) ProtoZoa
 
Answer & Explanation Answer: C) viruses (HTLV III)

Explanation:

AIDS: The term means Acquired Immunity Deficiency Synodrome. The virus attacks the T cells of the (white corpuscle type) blood and destroys them.

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Filed Under: Biology

Q:

Biological control is to check growth of 

A) plants B) animals
C) weeds D) one pest by another
 
Answer & Explanation Answer: D) one pest by another

Explanation:

Biological Control: This method is very effective. One pest is destroyed by another organism. For example the aphids are killed by lady beetle. The prickly pear is eradicted by cochineal insect. Here the advantage is, one does not use harmful chemicals which may get into the host plants.

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Filed Under: Biology

Q:

Monocarpic plants are those that produce fruits ...............during the life of the plant

A) once B) thrice
C) many times D) twice
 
Answer & Explanation Answer: A) once

Explanation:

Plants are of different types. Some grow well and then produce fruits before they die. In other words they fruit only once in their life. Such plants are said to be monocarpic. Other plants produce fruits every season. These are called polycarpic plants.

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Filed Under: Biology

Q:

The human heart is 

A) Neurogenic heart B) Myogenic heart
C) Pulsating heart D) Ampullary heart
 
Answer & Explanation Answer: B) Myogenic heart

Explanation:

Hearts are of several types. In some invertebrates the heart is simulated by the nervous system to do its work. Such hearts are called Neurogenic hearts. The Human heart is myogenic. i.e, it recieves the stimuli for contraction from the muscular node called sinu-auricular node or pace maker.

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Filed Under: Biology

Q:

The enzyme that is necessary to bring about clotting of blood is 

A) peptidase B) amylase
C) lipase D) thrombokinase
 
Answer & Explanation Answer: D) thrombokinase

Explanation:

The clotting of blood is a chain reaction initiated by the enzyme Thrombokinase produced by the platelets. This causes Prothrombin and calcium salts in plasma to join and produce thrombin. Thrombin combines with Fibrinogen to produce Fibrin threads which entangles the corpuscles  to create a clot.

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Filed Under: Biology

Q:

The disease Goitre is caused in persons who do not have in their diet sufficient

A) calcium B) sodium
C) iodine D) iron
 
Answer & Explanation Answer: C) iodine

Explanation:

Goitre is characterized by the swelling of the neck region. This is due to the enlargement of the thyroid gland which secretes hormone thyroxine. Thyroxine has iodine as an integral part of it. If there is not sufficient iodine in one's  diet, the thyroid gland swells up.

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Filed Under: Biology