Tag: botany

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Questions Related to botany

Multiple choice botany mineral nutrition in plants mechanism of absorption mineral absorption significance of transpiration

In the initial phase of mineral ion absorption, there is a rapid uptake of ions into ______ space of cells. Ions absorbed in this phase are ______ exchangable. It is _____ uptake as it ______ the expenditure of metabolic energy.

  1. inner, not freely, active, requires

  2. inner, freely, passive, requires

  3. outer, freely, passive, does not require

  4. outer, not freely, active, requires.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the principal stage, an underlying fast take-up of particles into the 'free space' or 'space' of cells the apoplast, is detached.

So, the correct option is 'outer, freely, passive, does not require'.

Multiple choice botany mineral nutrition in plants mechanism of absorption mineral absorption significance of transpiration

Choose the correct option

  1. $E\quad +\quad S\quad \longrightarrow \quad ES\quad \longrightarrow \quad E+P\quad \longrightarrow \quad EP$

  2. E\quad +\quad S\quad \longrightarrow \quad ES\quad \longrightarrow \quad EP\quad \longrightarrow \quad E+P

  3. E\quad +\quad S\quad \longrightarrow \quad ES\quad \longrightarrow \quad EP\quad \longrightarrow \quad E+P

  4. E\quad +\quad S\quad \longrightarrow \quad ES\quad \longrightarrow \quad EP\quad \longrightarrow \quad E+P
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice botany simple nutrients into cells mineral transport types of transport 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:

  1. At root hair cell

  2. At endodermal cell

  3. At pericycle

  4. At cortical cell
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.
Multiple choice botany simple nutrients into cells mineral transport types of transport translocation of organic solutes

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

  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.
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

A scientist associated with work on translocation is

  1. Arnon

  2. Calvin

  3. Dixon

  4. Munch
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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

  1. Source and sink

  2. Ascent of sap

  3. Diffusion

  4. Cyclosis
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

Which of the following act as sink?

  1. Root cells

  2. Fruit

  3. Seeds

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