Subject

biology

Class

CBSE Class 12

Pre Boards

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Sample Papers

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 Multiple Choice QuestionsShort Answer Type

1.

State the importance of biofortification. 


Biofortification is an important method to develop crops with a higher level of vitamins minerals, protein and healthier fats which improve public health. 

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2.

Name the phase all organisms have to pass through before they can reproduce sexually.


The phase that all organisms have to pass through before they can reproduce sexually is Juvenile phase. It is known as Vegetative phase in plants.

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3.

Write a difference between net primary productivity and gross productivity.


Gross primary productivity Net primary productivity
It is the amount of organic matter synthesised by producers per unit area in unit time. It is the amount of organic matter stored by producers per unit area in unit time.
It refers to the total productivity including energy utilised for respiration by the producers. It refers to the net productivity that is converted to organic matter excluding the energy utilised for respiration by the producers .
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4.

Name the enzyme produced by Streptococcus bacterium. Explain its importance in medical sciences. 


Streptokinase enzyme is produced by the bacterium Streptococcus.

It is used as a ‘clot buster’ which removes clots from the blood vessels of patients who have undergone myocardial infarction.

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5.

Mention the contribution of genetic maps in human genome project.


The contribution of genetic maps in human genome project. 

1. The gene mapping has made it possible to sequence the whole human genome.
2. Genetic maps have been used to find the exact chromosomal location.
3. The distances between markers and genes could be measured using the gentic maps.

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6.

How do algal blooms affect the life in water bodies? 


Algal bloom imparts a distinct colour, diminishes the water quality, increases fish mortality and is extremely toxic to human beings and animals.

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7.

How is “Rosie‟ considered different from a normal cow ? Explain.


Rosie was a transgenic cow. It was considered different from a normal cow as it produced human protein enriched milk. The milk contained 'human alpha-lactalbumin' and was nutritionally a more balanced product for human babies than the normal cow milk. 

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8.

Name the embryonic stage that gets implanted in the uterine wall of a human female. 


Blastocyst is the embryonic stage that gets implanted in the uterine wall of a human female.

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9.

Name the common ancestor of the great apes and man.


Australopithecus were the common ancestor of the great apes and man

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10.

Biotechnologists refer to Agrobacterium tumifaciens as a natural genetic engineer of plants. Give reasons to support the statement. 


Agrobacterium tumafaciens is known as a natural genetic engineer of a plant because it has the natural ability to integrates its plasmid genes into the plant genomes. It can deliver a piece of T-DNA in the plant genome. 

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