Tag: translocation of organic solutes

Questions Related to translocation of organic solutes

Which is the control point in roots where a plant adjust the quantity and quality of solute that reach the xylem:

botany simple nutrients into cells mineral transport types of transport translocation of organic solutes

  1. At root hair cell

  2. At endodermal cell

  3. At pericycle

  4. At cortical cell

Show answer
Correct Option: B
Explanation:
The plants need to change the sort and amount of solutes that achieve the xylem. The vehicle proteins of endodermal cell help in keeping up and changing solute development. 
So, the correct option is 'At endodermal cell'.

Much of starch is deposited in fruits as it matures. Which of the following explains that how the starch gets there?

botany simple nutrients into cells mineral transport types of transport translocation of organic solutes

  1. Starch solution passes through cells from xylem to fruit.

  2. Starch solution passes through companion cells to fruit.

  3. Starch grains passes through cells from xylem to fruit.

  4. A sugar solution passes through phloem cells to the fruit, where it is changed to starch.

Show answer
Correct Option: D
Explanation:

According to the most widely accepted theory of translocation of organic solutes - 'Mass flow hypothesis' or 'Pressure flow hypothesis', organic substances move in the sieve tubes from the region of higher osmotic concentration to the region of lower osmotic concentration in a mass flow, due to occurrence of a pressure gradient. 

Sucrose is the most commonly translocated sugar. At the source end sucrose is actively uploaded into the sieve tubes with the help of companion cells. At the storage organ / fruit end sucrose is actively downloaded from the sieve tubes and converted to starch for long term storage. 
As starch is tasteless, unripe fruits are tasteless and hard. Subsequently during fruit ripening starch is converted to sugars for utilisation during respiration. Hence, fruits become soft and sweet on ripening.

A scientist associated with work on translocation is

botany simple nutrients into cells mineral transport types of transport translocation of organic solutes

  1. Arnon

  2. Calvin

  3. Dixon

  4. Munch

Show answer
Correct Option: D
Explanation:

'Mass flow hypothesis' or 'Pressure flow hypothesis' to explain translocation was given by Munch, 1930. 

According to this theory organic substances move in the sieve tubes from the region of high osmotic concentration to the region of low osmotic concentration in a mass flow, due to occurrence of pressure gradient. This is the most widely accepted theory to explain translocation in plants.

Translocation of food in higher plants is related to the idea of

botany simple nutrients into cells mineral transport types of transport translocation of organic solutes

  1. Source and sink

  2. Ascent of sap

  3. Diffusion

  4. Cyclosis

Show answer
Correct Option: A
Explanation:

Translocation of organic solutes in phloem is bidirectional. The transport of prepared food is from source to sink. The source is the area, where sugars are present in larger amount either because they are synthesized there, example leaves or are stored there, example storage organs. 

Sink is the region of sugar utilisation. Where ever sugars are present in higher concentration, from there, sugars will be transported to a region, where sugars are required for metabolism or need to be stored. The loading of sugars at source as well as unloading of sugars at the sink both the processes are active and require expenditure of metabolic energy.

Which of the following act as sink?

botany simple nutrients into cells mineral transport types of transport translocation of organic solutes

  1. Root cells

  2. Fruit

  3. Seeds

  4. All of the above

Show answer
Correct Option: D
Explanation:

Translocation of organic solutes in phloem is bidirectional. The transport of prepared food is from source to sink. 

The source is the area, where sugars are present in larger amount either because they are synthesized there example leaves sink in the region of sugar utilisation. There is a dynamic balance between source and sink and they also keep on shifting depending on the physiological requirements of the plant. 
In some plants like carrot, radish etc., sugars are stored in roots. 
Hence, in these plants roots serve as sink. 
In most of the plants fruits serve as sink because they store food in epicarp. Seeds store food for the embryo. Seed store food in endosperm or cotyledons. Hence, seeds serve as sink.

Which pressure is responsible for ascent of sap?

biology transportation in plants and circulation in animals mineral transport types of transport translocation of organic solutes

  1. Negative hydrostatic pressure

  2. Positive hydrostatic pressure

  3. Root pressure

  4. All of the above

Show answer
Correct Option: C
Explanation:
  • In the Root Pressure, the root Xylem vessels absorb the minerals from the soil, as a result, the water potential outside the root increase and inside the root decreases so due to water potential difference water starts entering to the xylem of the root.

So, the correct answer is 'Root pressure'

Root pressure is caused by

biology transportation in plants and circulation in animals mineral transport types of transport translocation of organic solutes

  1. Osmosis

  2. Diffusion

  3. Passive transport

  4. Uphill transport

Show answer
Correct Option: A
Explanation:

Root pressure is caused in the Xylem vessels due to osmosis. It is a positive pressure which is developed due to Osmotic pressure which is high in the root as compared to the water column above.

Diffusion is a very slow process and hence plant do not just depend on it for the ascent of sap.
Since it is not occurring through specialised proteins or usage of energy, it is neither passive transport nor uphill transport 
So the correct answer is 'Osmosis'.

Which condition will not favour guttation?

biology transportation in plants and circulation in animals mineral transport types of transport translocation of organic solutes

  1. High moisture

  2. High DPD in leaf

  3. Accumulation of ions in root side

  4. Low light intensity

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Correct Option: B

Identify the correct sequence of movement of water in the root of higher plants.

biology transportation in plants and circulation in animals mineral transport types of transport translocation of organic solutes

  1. Epidermic - Cortex -Pericycle-endodermis - phloem

  2. Epidermis -Cortex-endodermis -pericycle -phloem

  3. Epidermis -Cortex -pericycle-endodermis -xylem

  4. Epidermis -Cortex-endodermis-pericycle -xylem

Show answer
Correct Option: A
Explanation:
Water will take the path of least resistance through root to reach the xylem. Water can move across the root via three different pathways. Once in the endodermal cells, the water freely enters the xylem cells where it joins the fast-moving column of water or transpiration stream, headed to the leaves.
So the correct option is 'Epidemic - Cortex -Pericycle-endodermis - phloem'.

Root pressure is generally not found in 

biology transportation in plants and circulation in animals mineral transport types of transport translocation of organic solutes

  1. Wheat plant

  2. Colocasia

  3. Pinus

  4. All of these

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Correct Option: A