Question

please answer fast , it's very important​

Answer 1

QUESTION [ 1 ] :-

Which of the following is a selectively permeable membrane?

a) nucleus

b) cell wall

c) plasma membrane

d) tonoplast

ANSWER [ 1 ] :-

c) Plasma membrane .  

  Selective permeability is a property of cellular membranes that only allows certain molecules to enter or exit the cell. This is important for the cell to maintain its internal order irrespective of the changes to the environment..

QUESTION [ 2 ] :-

it is used while preparing a temporary slide of onion peel. name it??

a) Methylene blue

b) saffranine

c) any of these can be used

d) methylene orange

ANSWER [ 2 ] :-

b) Saffranine.

   Saffranine is used to stain the peel. To observe the very small biological objects which is barely visible with our naked human eyes,we use microscope to optically zoom in that small biological object. ... Because these objects are often transparent or translucent which makes the observation process difficult..