Tag: biology

Questions Related to biology

State whether the following statements are true or false.
Carrier proteins are necessary for active transport to occur.

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Carrier proteins are those which facilitate diffusion of molecules across the cell membrane, they allow movement of molecules in and out of the cells against the concentration gradient. Active transport requires carrier proteins also called as pumps. They need ATP energy because the transport is uphill, against the concentration gradient.

So, the correct answer is 'True'. 

Choose the correct answer from the alternatives given.
The sodium potassium pump moves sodium and potassium ions across the plasma membrane by

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Facilitated transport

  2. Active transport

  3. Cotransport

  4. Endocytosis

Show answer
Correct Option: B
Explanation:

The sodium-potassium pump in a cell membrane works via active transport. It uses a carrier protein and utilizes ATP molecules. It transports the sodium ions to the extracellular space, increasing their concentration there and in turn moves potassium ions inside the cell. This pump moves three potassium ions inside the cell for every two sodium ions moved outside.


So, the correct answer is 'active transport'.

State whether the following statements are true or false.
ATP is required for active transport.

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Active transport is usually associated with accumulating high concentrations of molecules that the cell needs such as ions, glucose, and amino acids. The processes use chemical energy for this, it comes from the hydrolysis of the ATP molecule which maintains the electrochemical gradient. Hence ATP is required for active transport. 

So, the correct option is 'True'.

State whether the following statements are true or false.
In the sodium-potassium pump, sodium is transported out of the cell and potassium is trapsported into the cell as ATP is broken by a membrane protein.

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

ATP acts as a solute pump, it's an enzyme that pumps out sodium and pumping potassium in the cells, exports three sodium, and two potassium ions. It is an active transport leading to the hydrolysis of ATP molecules to provide the required energy.

So correct answer is 'True'.

Which one of the following processes requires an input of energy?

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Active transport

  2. Diffusion

  3. Facilitated diffusion

  4. Osmosis

Show answer
Correct Option: A
Explanation:

An input of energy is required in the process of active transport as it involves the movement of ions or molecules across a cell membrane from low to high concentration. The movement requires energy to maintain the electrochemical gradient.

So, the correct option is 'Active transport'.

State whether the following statements are true or false.
The movement of ions or molecules against a concentration gradient with the utilisation of energy is known as active transport.

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

The movement of ions or molecules against a concentration gradient (from lower to higher concentration) across a cell membrane with the utilization of energy is known as active transport. Active transport needs cellular energy which is given by ATP hydrolysis.

So, the correct option is 'True'.

Choose the correct answer from the alternatives given.
Which is the best definition of active transport?

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Movement of molecules from an area of their higher concentration to an area of their lower concentration

  2. Movement of water across a semi-permeable membrane from an area of high water concentration to an area of lower water concentration

  3. Movement of molecules from an area of their lower concentration to an area of their higher concentration

  4. Movement of a substance against its concentration through the release of energy from ATP

Show answer
Correct Option: D
Explanation:
In one form of transport across the cell membrane, ATP is utilized. The utilization of an ATP molecule provides the cell with an energy boost which enables the transport of different molecules across the cell membrane against their concentration gradient. This is termed as active transport of molecules across the cell membrane.

So, the correct answer is 'Movement of a substance against its concentration through the release of energy from ATP'.
Which of the following is an energy-dependent process?
biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Facilitated diffusion

  2. Active transport

  3. Endosmosis

  4. Exosmosis

Show answer
Correct Option: B
Explanation:

Active transport is an energy dependent process, in which ATP is utilised.

Which of the following is an energy dependent process?

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Facilitated diffusion

  2. Active transport

  3. Endosmosis

  4. Exosmosis

Show answer
Correct Option: B
Explanation:

Active transport (secretion) is an energy-dependent process that selectively moves a substance against its electrochemical gradient across a cell membrane. It is an energy dependent process, in which ATP is utilised.

Thus the correct option is B. 

Uphill transport i.e., movement of substances from their lower concentration to their higher concentration occurs in

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Simple diffusion

  2. Facilitated diffusion

  3. Active transport

  4. Both B and C

Show answer
Correct Option: C
Explanation:

In active transport, the movable carrier proteins are called pumps. They employ ATP energy for transport across the membrane. It is uphill transport, i.e., against concentration gradient and is faster than passive transport. The rate of active transport reaches the maximum when all the protein pumps are being used in transport(saturation effect). Carrier proteins are highly specific like enzymes. They are also sensitive to inhibitors that react with protein side chains. So, the correct answer is 'Active transport'.