Tag: simple nutrients into cells

Questions Related to simple nutrients into cells

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

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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.

Pacemaker is situated in the

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Wall of right atrium

  2. Interauricular septum

  3. Interventricular septum

  4. Wall of left atrium

Show answer
Correct Option: A
Explanation:
The actual structure that serves as the heart's primary pacemaker is called the sinoatrial node (SA node). The SA node is a little bundle of cells located in the wall of the right atrium, the small upper chamber on the right side of the heart.
Thus, the correct answer is 'Wall of right atrium.'

The pacemaker of heart is

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Foramen ovale

  2. Sinoatrial node

  3. Ductus arteriosus

  4. Bundle of His

  5. Vagus nerve

Show answer
Correct Option: B
Explanation:

Electrical impulses from the heart muscle cause your heart to beat (contract). This electrical signal begins in the sinoatrial (SA) node, located at the top of the heart's upper-right chamber (the right atrium). The SA node is sometimes called the heart's“natural pacemaker.”

So, the correct option is 'Sino-atrial node'.

Rate of heart beat is determined by

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Purkinje fibres

  2. Papillary muscles

  3. AV-node

  4. SA-node

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Correct Option: D

The heart beat is initiated and regulated by nodal tissue made of specialised cardiac muscles called

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Spongy tissue

  2. Purkinje tissue

  3. Alveolar tissue

  4. None of these

Show answer
Correct Option: B
Explanation:

Purkinje tissue is influenced by electrical discharge from the sinoatrial node. During the ventricular contraction portion of the cardiac cycle, the Purkinje fibres carry the contraction impulse from both the left and right bundle branch to the myocardium of the ventricles. In this way these fibres control and initiate heart beat.

So, the correct option is B. ( Purkinje tissue )

The action potential is conducted from the atria to ventricles by:

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Purkinje fibre

  2. SA node and AVN

  3. Bundle of his and SAN

  4. All of the above

Show answer
Correct Option: B
Explanation:
  • Sino-atrial node (SA node) is located the right upper corner of the right atrium and AVN(AV node) is located in the lower-left corner of the right atrium close to the atrioventricular septum.
  • The SAN can generate the maximum number of action potentials, i.e., $70-75 min^{–1}$, and is responsible for initiating and maintaining the rhythmic contractile activity of the heart. Therefore, it is called the pacemaker. From the SA node, the action potential is conducted from the atria to ventricles by AVN.
  • Hence the action potential is conducted from the atria to ventricles via SA node and AVN.
  • So, the correct answer is 'SA node and AVN'.