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Q:

The biogenetic law was proposed by

A) Alfred Russel Wallace B) Charles Darwin
C) Ernst von Haeckel D) Lamarck
 
Answer & Explanation Answer: C) Ernst von Haeckel

Explanation:

The biogenetic law states that ontogeny (study of development) repeats phylogeny (origin from previous group of racial history), The young one of the frog namely the tadpole is like a fish cosidered to be ancestral to frog.

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Q:

Lamarck's theory of inheritance of acquired characters was challenged by 

A) August Weismann B) Hugo de Vries
C) Herbert Spencer D) Carl Linnaeus
 
Answer & Explanation Answer: C) Herbert Spencer

Explanation:

August Weismann cut off the tails of mice for 21 successive generations and still they produced generation after generation of only tailed young ones. So he concluded that acquired characters are not inherited.

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Filed Under: Biology

Q:

Organisms that live in the deep sea are mainly

A) Herbivores B) Carnivores
C) Detritivores D) None of the above
 
Answer & Explanation Answer: C) Detritivores

Explanation:

Deep sea animals cannot produce food as there is no light. They have to depend upon the fall out of organic debirs raining down on them from surface layers. Hence they are detritivores.

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Q:

The phenomenon of summer sleep by animals is called

A) hibernation B) aestivation
C) laziness D) lethargy
 
Answer & Explanation Answer: B) aestivation

Explanation:

Aestivation is summer sleep. Many organisms like the snails do not find it comfortable in summer. They withdraw and lead a life with reduced BMR (basic Metabolic Rate) in a state of  dormancy.

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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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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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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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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