Subject

Biology

Class

CBSE Class 12

Pre Boards

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Sample Papers

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 Multiple Choice QuestionsShort Answer Type

1.

A garden pea plant (A) produced inflated yellow pod, and another plant (B) of the same species produced constricted green pods. Identify the dominant traits. 


In the garden pea plant the dominant traits are:

Inflated pod and green colour of the pod.

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2.

Name the following:

(a) The semi-dwarf variety of wheat is high-yielding and disease-resistant.

(b) Any one inter-specific hybrid mammal.

(a)  The semi-dwarf varieties of wheat that are high-yielding and disease resistant are Sonalika and Kalyan Sona.

(b) The inter-specific hybrid animal is Mule. 
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3.

Mention the unique flowering phenomenon exhibited by Strobilanthus kunthiana (neelakuranaji). 


Strobilanthus kunthiana exhibits the unique flowering phenomenon that it flowers once in 12 years.

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4.

Write the similarity between the wing of a butterfly and the wing of a bat. What do you infer from the above with reference to evolution?


Wings of a butterfly and the wings of a bat are similar in function that is both are used for flying. These two are the result of convergent evolution.

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5.

(a) Highlight the role of thymus as a lymphoid organ.

(b) Name the cells that are released from the above-mentioned gland. Mention how they help in immunity.

(a) Thymus being the primary lymphoid organ provides the micro-environment for the maturation of the T-lymphocytes.

(b) T- cells are released from the thymus. The T-lymphocytes help the B-cells to produce antibodies. They mediate the CMI (cell-mediated immunity)
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6.

Why is Eichhornia crassipes nicknamed as Terror of Bengal? 


Eichhornia crassipes is nicknamed Terror of Bengal because they caused havoc by their excessive growth by causing blocks in the waterways. They grew at a very high rate such that it was nearly impossible to remove completely. They caused imbalance in the ecosystem dynamics of the water body.

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7.

How does smoking tobacco in human lead to oxygen deficiency in their body? 


Smoking increases carbon monoxide (CO) content in blood and reduces the concentration of haembound oxygen. This causes oxygen deficiency in the body.

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8.

Why do clown fish and sea anemone pair up? What is this relationship called? 


Clown fish pairs up with the sea anemone to get protection from the predators. The relationship is called commensalism because only the fish is benefited from the pairing while the sea-anemone is neither benefited nor harmed.

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9.

Write the location and function of the sertoli cells in humans. 


Sertoli cells are found in testis. Its function is to provide nourishment to the germ cells.

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10.

Write what do phytophagous insects feed on


Phytophagous insects feed on plants.

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