Tag: botany

Questions Related to botany

Absorption of mineral elements from the soil occurs through

  1. Diffusion

  2. Active transport

  3. Osmosis

  4. All of the above


Correct Option: B
Explanation:

Absorption of mineral elements from the soil involves active transport by the cells. Minerals may also be absorbed as ions rather than salts.

In trees, death of protoplasts is essential for vital function such as

  1. Stomatal movements

  2. Food transport

  3. Water transport

  4. Both water and food transport


Correct Option: C
Explanation:

Water transport is a physical process and not a physiological process. It does not require living cells and protoplasm. The driving force is the transpiration pull generated by loss of water through leaves. This is the reason why xylem tracheids and vessels are dead on maturity. Food transport is a physiological process and requires living cells similarly stomatal movement also is a physiological process and requires living cells.

Nobel prize in 1991 for discovering the single ion channels in cell was awarded to

  1. Waston and Har gobind Khorana

  2. Erwin Neher and Bert Sakmann

  3. Nirenberg and Kornberg

  4. Holley and Matthaei


Correct Option: B
Explanation:

In 1991, the Nobel prize in medicine or physiology was given to Erwin Neher and Bert Sarkmann for the discovery of single ion channels in cells. They were able to develop a technique that registers very minute variations in electric currents that passes through a single ion channel. This new method helped them to watch the activity of a single molecule.  

Thus, the correct answer is option B.

The process by which minerals get absorbed is

  1. Active absorption

  2. Passive absorption

  3. Both A and B

  4. None of the above


Correct Option: C
Explanation:

The minerals are mainly absorbed by roots which are in direct contact with the soil. Absorption of water is known as water uptake. Short distance transport of water takes place from cell to cell  across the membranes involving physical processes such as diffusion, osmosis and water potential differences. Long distance transport involves complex processes such as root pressure and transpiration pull. transport There are two processes by which mineral absorption takes place:

1. There is rapid uptake of ions into the outer free surface passively down the gradient of electrochemical potential energy. 
2.  The movement of ions into the inner space requires the expenditure of energy and is called active uptake.
Thus, the correct answer is option C. 

Which statement is incorrect for ion-channels?

  1. They are protein

  2. Movement through them is simple diffusion

  3. Movement through them is from high to low concentration

  4. All ions pass through the same type of channel


Correct Option: D
Explanation:

Ion channels are special proteins through which ions flow along the concentration gradient. These channels are important, because the membrane is made up of bilayer of lipids and will not allow transport of water soluble ions. However lipid soluble components can dissolve in membrane lipids and can be transported across the membrane without special carrier or transport proteins.
But all ions cannot pass through same transport protein because volume of each ion will be different. There are different transport proteins for transport of different ions.

ATP is required for

  1. Active process

  2. Passive process

  3. All types of processes

  4. None of the above.


Correct Option: A

Which of the following shows that metabolic energy is required in the absorption of ions

  1. More ions absorption in presence of oxygen

  2. Less absorption of ions in presence of oxygen

  3. More ions absorption in presence of ATP

  4. More ions absorption in presence of NAD


Correct Option: C
Explanation:

The absorption of ions, involving use of metabolic energy is called active absorption. Energy is generally obtained from ATP.Therefore active absorption is linked to hydrolysis of ATP

Difference between active and passive modes of membrane transport is

  1. Active transport is confined to cations while passive is connected to anions

  2. Active transport is non-selective while passive one is selective

  3. Active transport requires metabolic energy while passive transport requires concentration gradients

  4. Active transport is more rapid.


Correct Option: A

Active transport of solutes in a living system is?

  1. Unidirectional

  2. Bidirectional

  3. Multidirectional

  4. Cyclic


Correct Option: A

Choose the correct answer from the alternatives given.
Active transport from outside to inside of molecules across a membrane requires:

  1. cyclic AMP

  2. acetyl chlorine

  3. ATP

  4. lecithin


Correct Option: C
Explanation:

Active transport, which is the movement of ions or molecules across a cell membrane in the direction opposite that of diffusion, that is, from an area of lower concentration to one of higher concentration, requires the assistance of a type of protein called a carrier protein, using energy supplied by ATP. So, the correct option is 'ATP'.