51. Raisins placed in water swell up due to
52. Root hairs absorb water from soil when
A. Osmotic concentration is same in the two
B. Solute concentration is higher in soil solution
C. Solute concentration is higher in root hairs
D. Absorption is active
Answer : Option D
53. A cell placed in strong salt solution will shrink because
A. Cytoplasm will decompose
B. Mineral salts will break the cell wall
C. Salt water enters the cell
D. Water comes out by exoosmosis
Answer : Option A
54. Osmosis defined as
A. Flow of solvent (water) through a semipermiable membrane from less concentrated solution to more concentrated solution.
B. Flow of solute from a semipermeable membrane
C. Flow of water without a membrane
D. None ot the above
Answer : Option A
55. A cell increase in volume if the external medium is
56. If a cell gets reduced in size when placed in solution, the solution is
57. In a hypertonic solution a cell’s water potential
A. Decreases
B. Increases
C. First increases then decreases
D. No change
Answer : Option A
58. An example of selectively permeable membrane is
A. Plasmalemma
B. Cell wall
C. Mitochondrial membrane
D. Chloroplast membrane
Answer : Option B
59. When beet root cylinders are washed and then placed in cold water, anthocyanin does not come out. This indicates that most likely the plasma membrane is
A. Permeable to enthocyanin
B. Impermeable to anthocyanin
C. Differentially permeable to anthocyanin
D. Dead structure
Answer : Option D
60. Purple cabbage leaves do not pass out colour in cold water but do so in hot water becasue
A. Hot water enters the cell faster
B. Pigment is not soluble in cold water
C. Hot water destroys cell walls
D. Hot water kills plasmalemma and makes it permeable
Answer : Option A