Tag: biology

Quizzes (1160) Questions (12174)

Questions Related to biology

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

Which one of the following is the correct statement for an active sodium-potassium ATPase ?

  1. It pumps out 3 Na-ions and pumps in 2 K-ions

  2. It pumps out 3 Na-ions and pumps in 3 K-ions

  3. It pumps out 3 Ca-ions and pumps in 2 K-ions

  4. It pumps out 3 Na-ions and pumps in 2 Ca-ions
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sodium-potassium pump is important to produce action potential by nerve cells. As it transport of three Na+ to the outside of the cell and the transport of two K+ ions to the inside. This changes the membrane potential on the inside, making the inside of the cell more negative or hyperpolarized, which leads to forward movement of electric impulse

So, the correct answer is 'It pumps out 3 Na$^+$and pumps in 2 K$^+$ '

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

The absorption of water due to expenditure of energy is called as ____________.

  1. Active absorption

  2. Non-smotic absorption

  3. Passive absorption

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 It is called water absorption 'through roots', rather 'by' roots. It occurs in rapidly transpiring plants during the daytime, because of the opening of stomata and the atmospheric conditions. The force for absorption of water is created at the leaf end i.e. the transpiration pull.

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

Active transport

  1. Releases energy

  2. Requires energy

  3. Produces ATP

  4. Produces a toxic substance
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

There are two types of absorption mechanisms i.e., active and passive transport. Active transport is the movement of solute or solvent molecules against the concentration gradient. It requires the expenditure of energy in the form of ATP. Thus, the correct answer is option B.

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

Active transport across cell membrane requires

  1. Glucose

  2. Steroids

  3. Energy in the form ATP

  4. Proteins and glucose
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In active transport, substances move against a concentration gradient across a cell membrane. Hence energy is required. The energy available in the body in the form of ATP is used to move this substance across the cell membrane. Thus the correct answer is option C.

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

Movement of ions r molecules against electrochemical gradient is called ______________.

  1. Pinocytosis

  2. Diffusion

  3. Active transport

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

Active transport is defined as the movement of molecules or ions across a cell membrane against their concentration or electrochemical gradient, requiring cellular energy.

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

Active absorption is affected by:

  1. Osmotic concentration

  2. Associate tissue structures

  3. Transpiration

  4. Sucking capacity of root hair
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Active absorption refers to absorption against the concentration gradient. Absorption of a solute from a region of low concentration to a region of higher concentration by the help of energy, is called active absorption. Hence, active absorption depends on osmotic concentration.

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

Active transport involves the transport of molecules across a cell membrane.
In order to establish and maintain a concentration gradient, which of the following condition is suitable?

  1. Free energy is used to drive molecules back-and-forth across the transmembrane protein.

  2. Free energy is used to drive molecules and across a transmembrane protein against the concentration gradient.

  3. No free energy is required.

  4. There must be an equal quantity of molecules on both sides of the membrane.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Free energy obtained from hydrolysis of ATP is used for the movement of solutes against their concentration gradient across the plasma membrane using a transport transmembrane protein also called pump

So, the correct answer is 'Free energy is used to drive molecules and across a transmembrane protein against the concentration gradient'

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

In the light of carrier concept, the transport of ion across the membrane against concentration gradient is

  1. Passive process

  2. Non-osmotic process

  3. Osmotic process

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

According to carrier concept for transport of ion in plants, transport is mediated by specific carriers. When the ion is transported against the concentration gradient, the ion carrier is activated in presence of ATP and a kinase enzyme. The activated carrier forms a complex with an ion at the outer surface and transported in. Because this process involves ATP, hence, it is called active process.

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

Carrier proteins are involved in the

  1. Active transport of ions

  2. Passive transport of ions

  3. Water transport

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Active transport is the movement of a substance across a membrane against its concentration gradient. Unlike channel proteins which only transport substances through membranes passively, carrier proteins can transport ions and molecules either passively through facilitated diffusion, or via secondary active transport.

Therefore D is the correct option.