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

The cell becomes turgid in solution which is

  1. Hypertonic

  2. Isotonic

  3. Hypotonic

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The cell becomes turgid in solution which is hypotonic because a hypotonic solution has more concentration of solvent molecules than the fluid inside the cell. So, the solvent molecules move inside the cell from the region of higher concentration to the lower concentration by the process of endosmosis. The cell swells and increases in size.
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

Water will enter a cell, if it is placed in solution less concentrated than cell sap due to

  1. Endosmosis

  2. Diffusion

  3. Imbibition

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

(A) Endosmosis is the movement of solution from outside of the cell to inside the cell.

(B) Diffusion is the movement of the molecule from higher concentration to the lower concentration.
(C) Imbibition is the special diffusion where water is absorbed by solid colloids to get an increase in the volume.
(D) Plasmolysis is the process of cell getting contracted due to the loss of water from the cell.
So, the correct answer is 'Endosmosis'.

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

Glucose is not stored in plants due to its ability to 

  1. Decrease osmotic pressure

  2. Increase osmotic pressure

  3. Increase turgor pressure

  4. Decrease turgor pressure
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Osmosis occurs only through the semi-permeable membrane. Osmosis is a gradient dependent process, osmosis is different from diffusion as it is characterized by a semi-permeable membrane.
  • Net direction and rate of osmosis depend on both pressure gradient and concentration gradient.
So, the correct answer is 'Increase osmotic pressure'.

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

The space between plasma membrane and cell wall of a plasmolysed cell surrounded by a hypertonic solution is occupied by

  1. Isotonic solution

  2. Hypotonic solution

  3. Hypertonic solution

  4. Water
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The hypertonic solution involves the movement of a solute particle from low concentration to high concentration. The water will move from a higher concentration to a lower concentration. The cell will swell up.

So, the correct option is 'Hypertonic solution'.

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

Choose the wrong statement.

  1. Cells swell in hypertonic solutions and shrink in hypotonic solutions.

  2. Water potential is the kinetic energy of water which helps in movement of water.

  3. Absorption of water by seeds and dry wood takes place by special type of diffusion called imbibition.
  4. $ \Psi _s $ is always negative.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The solute potential is always negative as it reduces osmotic pressure.

Absorption of water by seeds and embryo takes place by imbibition which leads to their growth and swelling respectively.
Water potential is the energy of water that helps it in moving.
Cells absorb water when kept in hypotonic solutions and they swell up while they lose water when kept in hypertonic solutions and shrink.
So the correct answer is 'Cells swell in hypertonic solutions and shrink in hypotonic solutions'.

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

Osmotic pressure of a cell kept in water is chiefly regulated by

  1. Vacuoles

  2. Plastids

  3. Ribosomes

  4. Mitochondria
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vacuoles are the organelles that store all the extra water and salts that are the basis of creating osmotic pressure in the cell. The vacuole takes up a huge central place in the cell. The solution outside the cell is hypertonic, hypotonic or isotonic with respect to the contents inside the vacuole. Plastids are the centres for photosynthesis, Ribosomes are small granule-like structures that help in protein synthesis whereas mitochondria generate energy for the cell by utilising sugars. 

So the correct answer is 'Vacuoles'.

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

RBC placed in distilled water will

  1. Burst

  2. Shrink

  3. Stick to one another

  4. Divide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

RBCs placed in distilled water will burst because distilled water is extremely hypotonic to the cytoplasm of the cell. This will involve the intake of enormous amounts of water and the cells will burst.

So the correct answer is 'Burst'.

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

Flaccid cell means

  1. Cell with turgidity

  2. Plasmolysed cell

  3. The cell in which water flows in and out of cell are in equilibrium

  4. The cell kept in hypotonic solution
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a cell is placed in an hypertonic solution water is transported out of the cell and the cell shrinks or shrivels or plasmolysed. On contrary when the cell is placed in hypotonic solution the water flows into the cell causing the cells to swell and finally leading to their lysis. However, when the cells are placed in isotonic solutions there will be continuous flow of water in and out of the cell and the cell is said to be in flaccid condition. Thus, the correct option of C.