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
A.
If both Assertion and Reason are true and the reason is the correct explanation of the assertion
The structure of cell membrane can be described by the fluid-mosaic model. It was given by Singer and Nicolson in 1972. The essential feature of fluid-mosaic model is cell membranes are considered to be quasifluid structures in which the lipids and proteins are in mosaic manner. It is considered to be as the lipid-protein association (mosaic) and also to be hydrophobic. The fluidity of the membrane is the result of this hydrophobic interaction, thus a cell membrane shows fluid behaviour.
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
Extranuclear inheritance is a consequence of the presence of genes in :
ER and mitochondria
lysosomes and ribosomes
ribosomes and chloroplast
mitochondria and chloroplasts
In prokaryotes, the genetic material is :
linear DNA with histones
circular DNA with histones
linear DNA without histones
circular DNA without histones
Vesicles of Smooth Endoplasmic Reticulum (SER) are most likely on their way to :
plastids
lysosomes
nucleolus
Golgi apparatus
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: 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.
