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Cell : The Unit of Life

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Biology

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Biology

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CBSE Gujarat Board Haryana Board

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Class 10 Class 12

Which one of the following cell organelles is enclosed by a single membrane?

  • Chloroplasts

  • Lysosomes

  • Nuclei

  • Mitochondria


B.

Lysosomes

All others except lysosomes have double membrane.

All others except lysosomes have double membrane.

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A complex of ribosomes attached to a single strand of RNA is known as 

  • Polymer

  • Polypeptide

  • Okazaki's fragment

  • Polysome


D.

Polysome

A chain of ribosomes attaches to a single mRNA is called polysome or polyribosomes.

A chain of ribosomes attaches to a single mRNA is called polysome or polyribosomes.

2077 Views

Water-soluble pigments found in plant cell vacuoles are

  • chlorophylls

  • carotenoids

  • anthocyanins

  • xanthophylls


C.

anthocyanins

Anthocyanins are water soluble pigments and appear red, purple depending on pH. 

Anthocyanins are water soluble pigments and appear red, purple depending on pH. 

2040 Views

One of the major components of cell wall of most fungi is

  • peptidoglycan

  • cellulose

  • hemicellulose

  • chitin


D.

chitin

Fungi cell wall is made of chitin. 

Fungi cell wall is made of chitin. 

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Mitochondria and choloroplast are :
I. semi-autonomous organelles.
II. formed by division of pre-existing  organelles and they contain DNA but lack protein synthesizing machinery. 

  • II is true but I is false

  • I is true but II is false

  • Both I and II are false

  • Both I and II are correct


B.

I is true but II is false

Mitochondria and chloroplast have DNA and are capable of self-replication, thus they are semi-autonomous bodies

The organelles do synthesize some of protein and hence they have the protein synthesizing machinery. However, most of the proteins are derived from the nucleus. 

Mitochondria and chloroplast have DNA and are capable of self-replication, thus they are semi-autonomous bodies

The organelles do synthesize some of protein and hence they have the protein synthesizing machinery. However, most of the proteins are derived from the nucleus. 

2617 Views