Biology Mcqs

Resolution power of a compound microscope is___________?

(A) 2.0 ?m

(B) 2-4 A

(C) 24 ?m

(D) 24 A

Submitted By: Ali Uppal


Extreme change in pH results in______________?

(A) Change in ionization of amino acids at the active site of the enzyme

(B) Change in the ionization of the substrate

(C) Denaturation of the enzyme

(D) Increase in the reaction rate

Submitted By: Ali Uppal


Who opposed the idea the cell is an empty space bounded by thick wall?

(A) Lorenz Oken

(B) Schwann

(C) Robert Brown

(D) Rudolph Virchow

Submitted By: Ali Uppal


Submitted By: Ali Uppal


Factory of Ribosomal systhesis is__________?

(A) Cytoplasm

(B) Nucleus

(C) Nucleolus

(D) Endoplasmic reticulum

Submitted By: Ali Uppal


The active site of an enzyme______________?

(A) Never changes

(B) Forms no chemical bond with substrate

(C) Determined by structure and the specificity of the enzyme

(D) They are non specific in their action

Submitted By: Ali Uppal


If the concentration of enzyme is kept constant and amount of substrate is increased a point is reached where increase in substrates concentration does not affect the reaction rate because of____________________?

(A) Enzymes get denatured at higher substrate conc

(B) Rate of reaction is indirectly proportional to substrate concentration at this point

(C) All the active sites on enzyme molecule are occupied

(D) None of these

Submitted By: Ali Uppal


Which statement is incorrect about Lock and Key Model________________?

(A) Specific enzyme can transform only a specific substrate

(B) Active site of an enzyme is a non flexible structure

(C) Active site does not change before during or even after the reaction

(D) It explains the mechanism of every chemical reaction

Submitted By: Ali Uppal


Strengthening material of prokaryotic cell wall is__________?

(A) Cellulose

(B) Chitin

(C) Inorganic salts silica waxes and ligin

(D) Peptidoglycan or Murein.

Submitted By: Ali Uppal


Submitted By: Ali Uppal