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Assertion : Nucleus is the controlling c...

Assertion : Nucleus is the controlling centre of a cell.
Reason : Pores in the nuclear envelop regulate the flow of materials in and out of the nucleus.

A

If both assertion and reason are true and reason is the correct explanation of assertion

B

If both assertion and reason are true but reason is not the correct explanation of assertion

C

If assertion is true but reason is false

D

If both assertion and reason are false.

Text Solution

Verified by Experts

The correct Answer is:
B
Nucleus is the controlling centre of a ceil as it contains chromosomes and genes. Chromosomes contain the DNA which by transcription prepare RNA which in turn leads to the formation of proteins by translation. These proteins regulate the various metabolic processes going in the cell. Besides this, nucleus contains genetic information for reproduction, development & behaviour of an organism.
Nuclear membrane is double layered, semipermeable and is perforated by minute, circular nuclear pores. The pore controls the passage of macromolecules like tRNAS, mRNAs, ribosomal proteins, enzymes etc. during different processes of transcription, translation etc.
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Read the statements below regarding the nucleus of a cell. Identify them as true or false and select the correct combination option. I. The nucleus displays an elaborate nucleoprotein fiber called chromatin during the interphase of the cell cycle. II. The space between the parallel membranes of the nuclear envelope is called the nucleoplasm. III. Nucleus was discovered first by Flemming. IV. The nuclear pores within the nuclear envelope are formed by the fusion of both membranes. {:("No.",I,II,III,IV),(1,"True","True","False","False"),(2,"True","False","False","False"),(3,"True","True","False","False"),(4,"True","False","False","True"):}