Tag: bio-chemistry

Questions Related to bio-chemistry

Diffusion pressure is directly proportional to:

  1. Concentration of molecules diffusing

  2. Kinetic energy of diffusing molecule

  3. Concentration gradient

  4. All of the above


Correct Option: A
Explanation:

The same conditions of temperature and pressure, the molar mass is proportional to the mass density. Therefore, the rate of diffusion of different gases is inversely proportional to the square root of their mass densities.

So, the correct option is 'Concentration of molecules diffusing'.

Rate of diffusion of $CO _2$ is $20$ times higher than $O _2$, as it depends upon?

  1. Solubility of gases

  2. Partial pressure

  3. Thickness of membrane

  4. All of these


Correct Option: D
Explanation:

Gas exchange is the process that occurs between oxygen and carbon dioxide. Oxygen is passed from the lungs to the bloodstream and carbon dioxide is eliminated from the bloodstream to the lungs. Exchange of Gas takes place in lungs between the alveoli and capillaries which are tiny blood vessels, placed at the walls of alveoli. The rate of diffusion depends on the thickness of the biological membrane which forms the boundary between the external environment and organisms.

Gas exchange takes place by simple diffusion based on a concentration/pressure gradient. The rate of diffusion depends not only on the solubility of gases but also on the thickness of the membranes involved in gas exchange.
So the correct answer is 'All of these'.

Movement of gases across plasma membrane occurs through ______________

  1. Osmosis

  2. Diffusion

  3. Imbibition

  4. None of these


Correct Option: B
Explanation:

Diffusion is a process in which the gaseous molecules spreads due to their kinetic energy and movement of molecules from their higher concentration to their lower concentration. Hence, The correct answer is option B.

A bottle of perfume is opened in the room opposite to you and within minutes you begin to smell the perfume. This phenomenon is a classic example of

  1. Dialysis

  2. Osmosis

  3. Active transport

  4. Diffusion


Correct Option: D
Explanation:

Diffusion is the process of spreading of the gaseous molecule according to their kinetic energy. In this process, particles move from an area of high concentration to an area of low concentration. If the perfume is sprayed in one corner of a room, it will be smelt soon after in the opposite corner. Since the perfume molecules are in constant random motion they bump into each other causing some molecules to be occasionally sent hurtling out of the mass. Gradually, the molecules spread out. 

Passive movement of substance from region of high concentration to the region of low concentration

  1. Inhibition

  2. Diffusion

  3. Osmosis

  4. All of the above


Correct Option: B
Explanation:

Diffusion is a passive movement of substances from the region of high concentration to the region of low concentration. Diffusion finally stops when the concentration of particles of two regions becomes the same. Diffusion occurs in both liquids and gases and can take place over long distances. Diffusion in gases is much faster than in liquids the diffusion rate of oxygen in the air is 1,00,000 times more than the diffusion rate of oxygen in the water.

So, the correct answer is B.

Water obeys 

  1. The law of pressure

  2. The law of diffusion

  3. Both A and B

  4. None of the above


Correct Option: C
Explanation:

Water obeys laws of pressure and diffusion both. Water moves from a region of high concentration or high pressure to a region of low concentration or low pressure.

So the correct answer is 'Both A and B'.

Diffusion occurs from

  1. Region of higher concentration to lower concentration

  2. Region of lower concentration to higher concentration

  3. Regions of equal concentration

  4. All of the above


Correct Option: A
Explanation:

Diffusion may be defined as the process of movement of gases liquids or solutes from the region of higher concentration to the regions of lower concentration till the molecules are uniformly disturbed throughout the available space. Many substances like gases liquids or solutes can diffuse simultaneously in different directions and at different rates in the same place without interfering with each other.
So, the correct answer is A.

Diffusion finally stops when

  1. The concentration of particles of two regions becomes the same

  2. Concentration of particle of one region becomes higher than the other

  3. Concentration of one region becomes lower than the other

  4. None of these


Correct Option: A
Explanation:

Diffusion finally stops when the concentration of particles of two regions becomes the same diffusion occurs in both liquids and gases and can take place over long distances diffusion in gases are much faster than in liquids the diffusion rate of oxygen in air is $1,00,000$ times more than diffusion rate of oxygen in water.

Which of the following states the importance of diffusion?

  1. Helps in exchange of gases during respiration.

  2. Helps in exchange of gases during photosynthesis.

  3. Responsible for transpiration.

  4. All of the above


Correct Option: D
Explanation:
May be defined as the process of movement of gases, liquids or solutes from the region of higher concentration to the regions of lower concentration till the molecules are uniformly distributed throughout the available space dissolved sugars and ions of potassium and sodium can pass through cell surface membranes by diffusion. Waste products such as urea also pass out of the cell through its membrane by cell diffusion helps in exchange of gases during respiration and photosynthesis. It is also responsible for transpiration.
So, the correct answer is D.

Substances which can be moved through diffusion in plants are

  1. Ions

  2. Sugar

  3. Urea

  4. All of the above


Correct Option: D
Explanation:

Diffusion may be defined as the process of movement of gases. liquids or solutes from the region of higher concentration to the regions of lower concentration till the molecules are uniformly distributed throughout the available space dissolved sugars and ions of potassium and sodium can pass through cell surface membranes by diffusion. Waste products such as urea also pass out of the cell through its membrane by cell diffusion helps in exchange of gases during respiration and photosynthesis. It is also responsible for transpiration.

So, the correct answer is D.