The outer membrane of the nucleus:
I. is continuous with the Endoplasmic reticulum
II. does not bear ribosomes.
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect
If the centromere is situated close to the end of a chromosome, it is called as:
Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. This leads us to which of the following as a probable hypothesis?
1. Disruption of one of these types of structure should necessarily disrupt each of the others as well.
2. Loss of basal bodies should lead to loss of all cilia, flagella, and centrioles.
3. Motor proteins such as dynein must have evolved before any of these four kinds of structure.
4. Natural selection for motility must select for microtubular arrays in circular patterns.
The presence of cholesterol in the plasma membranes of some animals.
1. enables the membrane to stay fluid more easily when cell temperature drops.
2. enables the animal to remove hydrogen atoms from saturated phospholipids.
3. enables the animal to add hydrogen atoms to unsaturated phospholipids.
4. makes the membrane less flexible, allowing it to sustain greater pressure from within the cell.
Prokaryotic cells have something unique in the form of:
1. Inclusion bodies
3. Cell wall
4. 70 S ribosomes
Gas vacuoles allow cyanobacteria to:
1. Store carbon dioxide for assimilation
2. Control their buoyancy
3. Provide anaerobic conditions to nitrogenase
4. Eliminate toxic ammonia
The lipid component of the plasma membrane mainly consists of:
Carotenoid pigments are found in:
(1) Only I
(2) Only I and II
(3) Only II
(4) I, II and III
Microbodies, which help to convert stored lipids into carbohydrates so they can be used for plant growth, are known as:
Ribosomes are produced in