Which of the following is responsible for the mechanical support, protein synthesis and enzyme transport?

• Cell membrane

• Mitochondria

• Dictyosome

• Endoplasmic reticulum

In prokaryotes, chromatophores are

• specialized granules responsible for colouration of cells

• structures responsbile for organizing the shape of the organism

• inclusion bodies lying free inside the cells for canying out various metabolic activities

• internal membrane systems that may become extensive and complex in photosynthetic bacteria

Many cells function properly and divide mitotically even though they do not have

• plasma membrane

• cytoskeleton

• mitochondria

• plastids

Three of the following statements regarding cell organelles are correct while one is wrong. Which one is wrong?

• Lysosomes are double membraned vesicles budded offfrom Golgi apparatus and contain digestive enzymes.

• Endoplasmic reticulum consists ofa network of membranous tubules and helps in transport, synthesis and secretion

• Leucoplasts are bound by two membranes, lack pigment but contain their own DNA and protein synthesizing machinery

• Sphaerosomes are single membrane bound and are associated with synthesis and storage of lipids

Assertion: Gram-negative bacteria do not retain the stain when washed with alcohol.

Reason: The outer face of the outer membrane of Gram-negative bacteria contains lipopolysaccharides, a part of which is integrated into the membrane lipids

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

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

• If assertion is true but reason is false

• If both assertion and reason are false.

Assertion : Mitochondria and chloroplasts are semi-autonomous organelles.

Reason : They are formed by division of pre-existing organelles as well as contain DNA but lack protein synthesizing machinery.

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false

• If both Assertion and Reason are false

Assertion : A cell membrane shows fluid behaviour.

Reason : A membrane is a mosaic or compositeof diverse lipids and proteins.

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

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

• If Assertion is true statement but Reason is false

• If both Assertion and Reason are false statements

298.

A prokaryotic cell lacks :

• nucleus

• nuclear membrane

• membrane bound organelles

• all of the above

Extranuclear inheritance is a consequence of the presence of genes in :

• ER and mitochondria

• lysosomes and ribosomes

• ribosomes and chloroplast

• mitochondria and chloroplasts

Vesicles of Smooth Endoplasmic Reticulum (SER) are most likely on their way to :

• plastids

• lysosomes

• nucleolus

• Golgi apparatus