Tag: diffusion

Questions Related to diffusion

Proton pump in thylakoid membrane is :

biology transport in plants diffusion transport in vascular plants types of transport

  1. PC

  2. Pheophytin

  3. Fd

  4. PQ

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Correct Option: A

Which region of plants is considered as supply end?

biology transport in plants diffusion transport in vascular plants types of transport

  1. Root

  2. Fruit

  3. Leaf

  4. Flower

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Correct Option: C
Explanation:

The translocation of sugars in a plant occurs from source to sink by active loading at source or supply end and active unloading at the sink end. The source and sink are not fixed and keep on changing depending on the physiology of plant. In water transport water is always transported from roots to the aerial parts but not so in case of sugars. 

Sugars are transported from a region, where they are present in high concentration, example leaves to regions of sugar utilisation or storage parts, example storage roots or tubers or fruits etc. 
Thus, storage organs like tubers, roots, fruits etc. serve as sink end and leaves acts as supply end.

Removal of a ring of bark from the trunk of a tree eventually kills it, because

biology transport in plants diffusion transport in vascular plants types of transport

  1. Water can not go up

  2. Fungi and insects attack exposed parts

  3. Food does not travel down and root becomes starved

  4. Air blocks the xylem

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Correct Option: C
Explanation:

In plants sugars are translocated by phloem tissue. This can be experimentally demonstrated by girdling experiments. In girdling experiments all tissues from phloem to epidermis, including secondary phloem are removed. This stops flow of sugars to plant parts below the level of girdle. Thus, the roots are starved and consequently the plant is killed.

A and B cells are contiguous. Cell A has OP$=10$ atm, TP $=7$ atm and DPD$=3$atm. Cell B has OP$=8$atm. TP$=3$ atm and DPD$=5$atm. The result would be?

biology transport in plants diffusion transport in vascular plants types of transport

  1. No movement of water

  2. Equilibrium between the two

  3. Movement of water from A to B

  4. Movement of water from B to A

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Correct Option: A

Photosynthetic food material is transported in the form of 

biology transport in plants diffusion transport in vascular plants types of transport

  1. Glucose

  2. Sucrose

  3. Starch

  4. Fructose

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Correct Option: B
Explanation:

Plants photosynthesize to produce sugars. Sugars are produced as monosaccharides- glucose or fructose. They are transported in the disaccharide form of sucrose through phloem tissue. Sugars are stored as polysaccharides, starch in storage organs.

Factors like plasmolysis, deplasmolysis, root pressure, turgidity, flacidity in plants are responsible for

biology transport in plants diffusion transport in vascular plants types of transport

  1. Absorption of water and minerals in plants

  2. Movement of water and minerals inside roots of the plants

  3. Movement of water and minerals upward in the stem

  4. All of the above

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Correct Option: D
Explanation:

The absorption of water and minerals from the soil by the roots of plants and their movement inside roots of the plant and subsequently its upward movement in stem and other aerial parts of the plant body is because of the following phenomenon:-
Imbibition
Diffusion
Osmosis
Osmotic pressure
Root pressure
Turgidity and flacidity
Plasmolysis and deplasmolysis 

Which of the factor is responsible for absorption and water and minerals in plants ?

biology transport in plants diffusion transport in vascular plants types of transport

  1. Plasmolysis

  2. Turgidity

  3. Osmotic pressure

  4. All of the above

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Correct Option: D
Explanation:

The absorption of water and minerals from the soil by the roots of plants and their movement inside roots of the plant and subsequently its upward movement in stem and other aerial parts of the plant body is because of the following phenomenon:-
Imbibition
Diffusion
Osmosis
Osmotic pressure
Root pressure
Turgidity and flacidity
Plasmolysis and deplasmolysis

Ringing experiment is to show

biology transport in plants diffusion transport in vascular plants types of transport

  1. Translocation of food

  2. Passive absorption

  3. Stomatal opening and closing

  4. None of the above

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Correct Option: A
Explanation:

In ringing experiment a complete ring of tissue is removed outside the vascular cylinder at a particular height from ground in a dicot plant. As the xylem is intact water can move freely to the aerial parts from roots. But the sugars cannot move down to roots from aerial parts, because of the removal of phloem tissue, which occurs in the outer cylinder and is removed in ringing experiment. 

A prominent swelling is observed just above the point of removal of ring of tissue due to accumulation of sugars. This experiment proves the respective roles of xylem and phloem in transportation of water and sugars.

I. Assertion: sugar is translocated to buds for growing them into flowers.
II. Reason:  xylem transport food through the plant.

biology transport in plants diffusion transport in vascular plants types of transport

  1. I and II both are correct and II is correct explanation for I

  2. I is correct and II is incorrect

  3. I and II both are false

  4. I and II both are correct but II is not correct explanation to I

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Correct Option: B
Explanation:

The increased contents within the cells exert a high amount of pressure on their wall. This pressure moves the food material to the adjacent cells with low pressure. This allows the phloem to move material according to the plants needs.

Root pressure theory and cohesion adhesion theory is possible due to _____

biology transport in plants diffusion transport in vascular plants types of transport

  1. Phloem

  2. Xylem trachieds

  3. Parenchymatic tissue

  4. None of the above

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Correct Option: B
Explanation:

There are two types of vascular tissues present in the plants viz. Xylem and Phloem. Xylem is responsible for transport of water and some minerals. Phloem is responsible for transport of food and minerals.