Tag: bio-chemistry

Quizzes (82) Questions (1918)

Questions Related to bio-chemistry

Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

The given table shows properties of four cells systems A, B, C and D. The maximum rate of inward diffusion of water will be observed in which of these systems?

System Intracellular concentration of water Extracellular concentration of water
A $0.09$M $0.11$M
B $0.2$M $0.5$M
C $0.05$M $0.7$M
D $0.03$M $0.6$M

  1. System A

  2. System B

  3. System C

  4. System D
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Diffusion of water will occur from higher concentration to lower concentration. Maximum rate of inward diffusion of water will occur where concentration difference is maximum. System C has maximum concentration difference of 0.65M. Hence, maximum diffusion will occur in system C.

So, the correct answer is 'System C'.
Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

Movement of the molecules of solids, gases or liquids from the region of their higher concentration to the region of their lower concentration is known as ___________.

  1. Diffusion

  2. Osmosis

  3. Imbibition

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

Diffusion is the movement of the particles of different substances from the region of their higher concentration, free energy or diffusion pressure to the region of their lower concentration, free energy or diffusion pressure.

Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

Water in adjacent xylem moves into the phloem by process of :

  1. Simple diffusion

  2. Active transport

  3. Osmosis

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

Water is passively transported into the roots and then into the xylem. The forces of cohesion and adhesion cause the water molecules to form a column in the xylem. Water moves from the xylem into the mesophyll cells, evaporates from their surfaces and leaves by diffusion through the stomata. The increased solute concentration causes water to move by osmosis from the xylem into the phloem. The positive pressure that is produced pushes water and solutes down the pressure gradient. So, the correct answer is "Osmosis".

Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

In photosynthesis, oxygen is given out by the process of

  1. Diffusion

  2. Osmosis

  3. Transpiration

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

Diffusion is a process in which the molecules intermingle due to their kinetic energy and movement of molecules is from higher concentration to lower concentration. During photosynthesis, the plant produces oxygen as a byproduct and hence the concentration of oxygen inside the cell is higher than the outer environment. Plant releases oxygen in external environment through diffusion process.

Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

Aquatic plants lose most of their metabolic wastes by .......... process.

  1. Diffusion

  2. Osmosis

  3. Reverse osmosis

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

Aquatic plants lose most of their metabolic wastes by diffusion directly into the water, surrounding them as the concentration of that metabolic wastes is more in the cell as compared to the surroundings. They do not have to store the waste products as terrestrial plants do. Thus, the correct answer is option A.

Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

Name the process which is useful for the movement of substances like CO$ _2$ and O$ _2$ across the cell membrane.

  1. Diffusion

  2. Osmosis

  3. Active diffusion

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

CO$ _2$ and O$ _2$ are gases so, they move in and out of the cell by diffusion. Diffusion is a process in which the gaseous molecules spreads, due to their kinetic energy and movement of molecules is from higher concentration to lower concentration. 

Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

Which is incorrect ?

  1. Rate of diffusion is directly proportional to concentration.

  2. Rate of diffusion is inversely proportional to concentration.

  3. Diffusion is movement of particles from low to high electrochemical potential.

  4. Example of diffusion is opening of scent or ammonia in one corner.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Diffusion is the movement of water molecules from higher concentration to lower concentration. It also transfers the molecule along the electrochemical potential gradient.

So, the correct answer is 'Diffusion is the movement of particles from low to high electrochemical potential.'

Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

The given table shows properties of four cells systems A, B, C and D. The maximum rate of inward diffusion of water will be observed in which of these systems?

System Intracellular concentration of water  Extracellularconcentration of water
A 0.09 M 0.11 M
B 0.2 M 0.5 M
C 0.05 M 0.6 M
D 0.03 M 0.7 M

  1. System A

  2. System B

  3. System C

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

A.In the system A, inward diffusion of water takes place with slow rate

B. In the system B, inward diffusion of water takes place with medium rate.

C.In the system C, inward diffusion of water takes place with maximum rate

D.In the system D, inward diffusion of water takes place with high rate

So, the correct option is ‘System C’.

Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

The factor which does not affect the rate of alveolar diffusion is

  1. solubility of gases

  2. thickness of the membranes

  3. pressure gradient

  4. reactivity of the gases.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$O _{2}$ and $CO _{2}$ are exchanged in the alveoli by simple diffusion. The factors that affect the diffusion are pressure gradient of the gases, solubility of the gases and the thickness of the membranes involved in diffusion.

Multiple choice bio-chemistry proteins denaturation of protein proteins and amino acids proteins and enzymes

Primary structure of a protein is?

  1. sequence in which $\alpha-$ amino acids are linked to one another

  2. sequence in which amino acids of one polypeptide chain are joined to other chains

  3. the folding patterns of polypeptide chains

  4. the pattern in which the polypeptide chain are arranged
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The primary structure of a protein refers to the sequence of amino acids in the polypeptide chain. The primary structure is held together by peptide bonds that are made during the process of protein biosynthesis.