Tag: bio-chemistry

Questions Related to bio-chemistry

Unlike plant cells, animal cells have________

  1. No vacuoles

  2. 1 vacuole

  3. 2 vacuoles

  4. Many vacuoles


Correct Option: D
Explanation:

Explanation: Unlike a large single vacuole in the centre of plant cells, animal cells can have many vacuoles.

Which of the following characters distinguishes plant cells from animal cells?

  1. Cell wall

  2. Glyoxysomes

  3. Plastids

  4. All of the above


Correct Option: D
Explanation:
Plastids are present in plant cells, whereas, an animal cell these are usually absent. It helps to trap sunlight for photosynthesis.
Glyoxysomes are present in the plant cell but are absent in an animal cell. It helps in the storage of fats in germinating cells.
The cell wall is present outside of plant cell and absent in an animal cell. It gives rigidity in a plant cell.
So, the correct answer is option D.

Plant cells differ from animal cells in having

  1. Mitochondria

  2. Cell wall

  3. Ribosomes

  4. Golgi bodies


Correct Option: B
Explanation:

Plant cell and animal cells are mostly similar because both are eukaryotic cells but the only difference is that plant cell contains cell walls, vacuoles, and chloroplasts.

Hence, the correct answer is 'cell wall'.

The pigment, melanin in animals protects them from UV radiations and is functionally equivalent pigment in plants is 

  1. Melanin only

  2. Carotenes

  3. Anthocyanin

  4. Both B and C


Correct Option: C
Explanation:

Anthocyanin is a red colour, water-soluble pigment found in plant cell vacuoles and cell walls. It is not involved in the process of photosynthesis but serves to attract insects and animals to flowers and fruits. It also serves to protect plant cell from high energy radiations like melanin pigment in animals.

A mixture containing DNA fragments, A, B, C and D, with molecular weights of $A + B =C, A>B$ and $D>C$, was subjected to agarose gel electrophoresis. The positions of these fragments from cathode to anoe sides of the gel would be

  1. $D, C, A, B$

  2. $A, B, C, D$

  3. $C, B, A, D$

  4. $B, A, D, C$


Correct Option: A
Explanation:

Gel electrophoresis is the techniques by which negatively charged DNA fragments separate according to their molecular mass and the principle says that lighter goes the maximum distance that means heavy DNA stops first as D is heavier it separates first while B at last.

So the correct option is 'D,C,A,B'.

Gel electrophoresis is a

  1. Technique of separation of charged molecules under the influence of magnetic field

  2. Technique of incorporation of DNA molecules into the cell through transient pores made due to electrical impulses

  3. Technique of separation of DNA fragments through the pores of agarose gel under the influence of electric field

  4. Technique of separation and purification of gene products


Correct Option: C
Explanation:
Electrophoresis is a technique of separation of molecules such as DNA, RNA or protein, under the influence of an electrical field, so that they migrate in the direction of electrode bearing the opposite charge, viz. positively charged molecules move towards cathode (-ve electrode) and negatively charged molecules travel towards anode (+ve electrode) through a medium/matrix. Since DNA fragments are negatively charged molecules, they can be separated by allowing them to move towards the anode (+ve electrode) under an electric field through a matrix of agarose gel.
So, the correct answer is 'Technique of separation of DNA fragments through the pores of agarose gel under the influence of electric field'.

Gel electrophoresis is a

  1. Technique of separation of charged molecules under the influence of magnetic field

  2. Technique of incorporation of DNA molecules Into the cell through transient pore made due to electrical impulses

  3. Technique of separation and isolation of DNA fragments through the pores of agarose

  4. Technique of separation and purification of gene products.


Correct Option: A
Explanation:

Electrophoresis is defined as a technique of separation of the charged molecules of the substance in a solution, by subjecting them to an electric field. The technique helps to determine the number, amount and the mobility of the components in a given sample or separate them. It is also used to obtain information about the electrical double layer, surrounding the particles. Differential migration of the charged molecules in the presence of the electric field is the main principle of electrophoresis. The resolving power of electrophoresis was greatly improved by the introduction of a technique called zone technique. The zone electrophoresis performed by using gel is referred to as gel electrophoresis. 

So the correct option is 'technique of separation of charged molecules under the influence of magnetic field'.

DNA or RNA segment tagged with a radioactive molecule is called

  1. Probe

  2. Clone

  3. Plasmid

  4. Vector


Correct Option: A

Which technique is used in separating fragments of DNA ______________.

  1. Eastern blotting

  2. Western blotting

  3. Northern blotting

  4. Southern blotting


Correct Option: D

The universal DNA probe is made up of repeated tandems of?

  1. TATA

  2. GATA

  3. CACA

  4. ATGA


Correct Option: A