Tag: bio-chemistry

Quizzes (82) Questions (1918)

Questions Related to bio-chemistry

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

What will happen if a plant and animal cell is put in a hypotonic solution?

  1. Cell swells

  2. Cell shrinks

  3. Cell bursts

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hypotonic solution is a solution which, contains lesser solute concentration. If animal and plant cells are kept in a hypotonic solution then endosmosis will occur. Endosmosis is a process in which the water molecules move from outside of the cell of lower solute concentration to the inside of the cell of higher solute concentration through the cell membrane or cell wall. Due to endosmosis, both animal and plant cells will swell. So, the correct answer is option A.

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

What will be observed when a plant or animal cell is put in a hypertonic solution?

  1. Cell swells

  2. Cell shrinks

  3. Cell bursts

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A Hypertonic solution is a solution, which contains higher solute concentration. If animal and plant cells are kept in hypertonic solution then exosmosis will occur. Exosmosis is a process in which the water molecules move from inside of the cell of lower solute concentration to the outside of the cell of higher solute concentration through the cell membrane. Due to exosmosis, both animal and plant cells will shrink. 

So, the correct answer is option B.

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

If cells of onion peel and RBC are separately kept in hypotonic solution, what among the following will take place? 

  1. Both the cells will swell

  2. RBC will burst easily while cells of onion peel will resist the bursting to some extent

  3. Both A and B

  4. RBC and onion peel cells will behave similarly
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hypotonic solution is a solution which contains lesser solute concentration. If RBC is kept in hypotonic solution, then the water molecules will move from hypotonic solution to RBC. This process is called as endosmosis in which the water molecules move from lower solute concentration to higher solute concentration through the membrane of RBC. Due to this, the cell membrane of RBC will not be able to tolerate the pressure and it will burst eventually. If onion peel is kept in hypotonic solution, then endosmosis will occur. As onion cell possess cell wall along with the cell membrane the onion cell will take a longer time to burst than RBC, but it will burst eventually.

So, the correct answer is option C.

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

Mammalian liver cells will swell, if they are kept in 

  1. Hypertonic solution

  2. Hypotonic solutions

  3. Isotonic solution

  4. Isothermal solutions
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A Hypertonic solution is a solution, which contains higher solute concentration. If mammalian liver cells are kept in hypertonic solution then exosmosis will occur. Exosmosis is a process in which outward movement of water molecules takes place from inside of lower solute concentration to the outside of higher solute concentration through the cell membrane. Due to exosmosis, mammalian liver cells will shrink. So, the correct answer is option B.

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

Grapes were put in a concentrated sugar solution. On examination after 12 hours, the grapes were shrunken. This is because

  1. Grapes become sweeter

  2. Water evaporates from the solution

  3. Sugar induces disintegration of grapes

  4. Loss of water from grapes by osmosis
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Grapes were put in sugar solution i.e., in hypertonic solution. Due to which exosmosis occurs in which outward movement of the water molecules from the lower solute concentration to higher solute concentration takes place through grapes covering. It results in shrinking of grapes. Therefore, option D is correct.

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

When amoeba is placed in a hypertonic medium, it shrinks. Why does this happen? 

  1. Due to exosmosis

  2. Due to endosmosis

  3. Due to both

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

If amoeba is kept in hypertonic solution then exosmosis occurs in which the water molecules move outward from cell of lower solute concentration to surrounding medium of higher solute concentration through the cell membrane. Due to exosmosis, amoeba will shrink. 

Therefore, option A is correct. 

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

A single-celled organism which has contractile vacuole to move water from inside to outside of the cell was studied in an experiment in which the organism was placed in water with different salt concentrations. The rate at which the contractile vacuole contracted to pump out excess water was recorded.

Salt conc. Rate of contractile vacuole contractions per minute
Very high 2
High 8
Medium 15
Low 22
Very Low 30

Which of the following explains the observed relationship between the rate of contractile vacuole contraction and the salt concentration?

  1. When the salt concentration outside the cell is very low, osmosis causes body salts to move outside the cell, increasing water content in body and the contractile vacuole needs to contract rapidly

  2. When the salt concentration outside the cell is very high, diffusion causes water to move outside the cell, and the contractile vacuole does not need to contract as rapidly

  3. When the salt concentration outside the cell is very low, diffusion causes water to move outside the cell, and the contractile vacuole contractions are increased

  4. When the salt concentration outside the cell is very high, osmosis causes water to move outside the cell, and the contractile vacuole does not need to contract as rapidly
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The lower the concentration of the salt solution, the higher will be the water potential of that solution. The higher the water potential, the greater is the tendency for water to enter the cell by osmosis. If there is more water entering by osmosis, then the contractile vacuole will have to fill up and empty more frequently. 

So, the correct answer is option D.

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

All of the following involves osmosis except

  1. Water passing from a root hair to adjacent cells.

  2. Water passing from a xylem vessel element to xylem vessel element above it.

  3. Water entering a mesophyll cell from the xylem vessel element.

  4. Water from soil entering a root hair.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water passing from a xylem vessel element to xylem vessel element above it due to the transpiration pull exerted by the mesophyll cells. However, the transfer of water from the soil to the root is due to osmosis.

Therefore, the correct answer is option B.

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

OP of a cell can be measured by 

  1. Manometer

  2. Photometer

  3. Calorimeter

  4. Plasmolysis
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Manometer is a device that is used to measure pressure. Photometer is a device that is used to the intensity of light. Calorimeter is a device that is used to measure the amount of heat involved in a reaction. Osmotic pressure is the pressure that must be applied in order to prevent the passage of solvent due to osmosis. The OP of a cell can be measured by plasmolysis. The OP of a cell is equal to the OP of a solution that results in the incipient plasmolysis in the cell.

Thus, the correct answer is option D.

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

In root hair, water enters due to 

  1. Diffusion

  2. W.P.

  3. T.P.

  4. O.P.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

(A) Diffusion is the movement of the water molecule from higher concentration to lower concentration.

(B) Wall pressure is the pressure applied by the cell wall against the turgor pressure.
(C) Turgor pressure is pressure applied against the wall pressure.
(D) Osmotic pressure is the pressure applied to prevent osmosis that is the movement of the water molecule from a lower solute concentration to a higher concentration through a semi-permeable membrane. Absorption of water through roots is by osmotic pressure.
So, the correct answer is 'Osmotic pressure'.