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What is the direction of movement of sugars in phloem?

  • Option 1)

    Non-multidirectional

  • Option 2)

    Upward

  • Option 3)

    Downward

  • Option 4)

    Bi-directional

  Translocation - The transport of substances over long distances through the vascular system, xylem and phloem. -       Transportation of nutrients can occur from leaves to roots and other parts of plants or from roots to the new leaves. Hence,sugar transport is bidirectional.Option 1)Non-multidirectionalOption 2)UpwardOption 3)DownwardOption 4)Bi-directional

Xylem translocates:

  • Option 1)

    water only

  • Option 2)

    Water and mineral only

  • Option 3)

    Water, mineral salts and some organnic nitrogen only

  • Option 4)

    Water, minerals salts and some organic nitrogen and hormones

  Ascent of sap - The upward movement of water from the root to aerial parts of the plant body. -     Xylem is the complex conducting tissue in the plants. It is responsible for the translocation of water, mineral salts and ions. Plants utilize nitrogen in the form of ammonia () or nitrate  ions. Hence organic nitrogen is not translocated. The transport of hormones majorly occurs in...

Grass leaves curl inwards during very dry weather. Select the most appropriate reason for the following:

  • Option 1)

    Closure of stomata

  • Option 2)

    Flaccidity of bulliform cells

  • Option 3)

    Shrinkage of aire spaces in spongy mesophyll

  • Option 4)

    Tyloses in vessels

  Opening and closing of stomata - This is governed by the change in osmotic pressure or turgidity of guard cells. - wherein When guard cells are turgid, stomata open and when guard cells are flaccid, stomata close.       The rolling or curling of grass leaves is mainly done due to bulliform cells. These are large bubble - shaped cells distributed between epidermal cells of the leaf. During...

Thiobacillus is a group of bacteria helpful in carrying out:

  • Option 1)

    Nitrogen fixation

  • Option 2)

    Chemoautotrophic fixation

  • Option 3)

    Nitrification

  • Option 4)

    Denitrification

  Denitrification - Nitrates are reduced to gaseous compounds of nitrogen by Pseudomonas denitrificans, Thiobacillus denitrificans, Micrococcis denitrificans - wherein       Thiobacillus denitrificans is a bacteria invovled in denitrification. It's actions result in convesion of nitrates in soil to free atmospheric nitrogen.  Option 1)Nitrogen fixationOption 2)Chemoautotrophic fixationOption...

Respiratory Quotient(RQ) value of tripalnitin is:

 

  • Option 1)

    0.9

  • Option 2)

    0.7

  • Option 3)

    0.07

  • Option 4)

    0.09

  Respiratory quotient (RQ) - Ratio of volume of CO2 evolved to the volume of oxygen consumed per unit time per unit weight at standard temperature and pressure. - wherein     To identify the RQ value, firstly the ratio of the volume of carbon dioxide given off in respiration to that of the O2 consumed that has a value near 1 when the organism is burning chiefly carbohydrates, near 0.7 when...

It takes very long time for pineapple plants to flower. Which combination of  hormones can be applied to artificially induce flowering in pineapple plants through out the year to increase the yields?

 

  • Option 1)

    Auxin and Ethyelene

  • Option 2)

    Gibberellin  and Cytokinin

  • Option 3)

    Gibberellin and Abscisic acid

  • Option 4)

    Cytokinnin and Abscisic acid

 
  Functions of Ethylene - Mainly concerned with maturation and ripening of fruits by enhancing respiration rate Stimulates transverse or isodiametric growth Inhabits longitudinal growth Induce flowering in pineapple Promotes Senescence and Abscission Breaks seed and bud dormancy Promotes root growth and root hair formation Promotes female flowers - wherein Commercial compound of ethylene -...

What is the site of perception of photoperiod necessary for the induction of flowering in plants?

 

  • Option 1)

    Pulvinus

  • Option 2)

    Shoot apex

  • Option 3)

    Leaves.

  • Option 4)

    Lateral buds

     

option 3

Convesion of glucose to glucose - 6 - phosphate, the first irrevesible reaction of glycolysis, is catalysed by:

 

  • Option 1)

    Aldolase

  • Option 2)

    Hexokinase 

  • Option 3)

    Enolase

  • Option 4)

    Phosphofructokinase

The answer to this question is hexokinase.

Medical
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Which one of the following is not an essential mineral element for plants while the remaining three are?

  • Option 1)

    Iron(b)

  • Option 2)

    Manganese

  • Option 3)

    Cadmium

  • Option 4)

    Phosphorus

 

Answer is CADMIUM . Remaining three are essential.(browsed from internet)

Medical
348 Views   |  

You are given a tissue with its potential for differentiation in an artificial culture. Which of the following pairs of hormones would you add to the medium to secure shoots as well as roots?

  • Option 1)

    IAA and gibberellin

  • Option 2)

    Auxin and cytokinin

  • Option 3)

    Auxin and abscisic acid

  • Option 4)

    Gibberellin and abscisic acid

 
  Function of Cytokinins - Promote rapid cell division Promote nutrient mobilisation Delay leaf senescene Overcome opical dominance Promote lateral bud growth   -    Auxin and cytokinin ratio plays important role in root and shoot growth.    Option 1) IAA and gibberellin Incorrect option Option 2) Auxin and cytokinin Correct option Option 3) Auxin and abscisic acid Incorrect option Option...
Medical
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A few drops of sap were collected by cutting across a plant stem by a suitable method. The sap was tested chemically. Which one of the following test results indicates that it is phloem sap?

  • Option 1)

    Acidic

  • Option 2)

    Alkaline

  • Option 3)

    Low refractive index

  • Option 4)

    Absence of sugar

 
As discussed in Bleading - Exudation of sap or watery solution from the cut or injured parts of the plant. - wherein It occurs due to root presure, phloem pressure, local pressure in xylem and latex or resin.    Sap from the injury or cut is due to phloem pressure or local xylem pressure. This results in pumping of protons from companion cells to outside, thus sap becoming alkaline.    Option...
Medical
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Oxidative phosphorylation is

  • Option 1)

    formation of ATP by transfer of phosphate group from a substrate to ADP

  • Option 2)

    oxidation of phosphate group in ATP

  • Option 3)

    addition of phosphate group to ATP

  • Option 4)

    formation of ATP by energy released from electrons removed during substrate oxidation

 
As discussed in Oxidalive phosphorylation - Synthesis of energy such ATP molecules with the help of energy librated during oxidation of reduced coenzymes (NADH, FADH2) produced in respiration, his is carried out in ETS and energy is generated through chemoiosmosis. - wherein Occours in the inner mitochondria membrane.     Oxidative phosphorylation is ATP synthesis by energy liberated during...
Medical
273 Views   |  

Which of the following biomolecules is common to respiration-mediated breakdown of fats, carbohydrates and proteins?

  • Option 1)

    Glucose-6-phosphate

  • Option 2)

    Fructose 1,6-bisphosphate

  • Option 3)

    Pyruvic acid

  • Option 4)

    Acetyl CoA

 
Acetyl  is a connecting link between glycolysis and Kreb's cycle. Proteins, amino acids and fats enter the Kreb's cycle for metabolism. Option 1) Glucose-6-phosphate This option is incorrect. Option 2) Fructose 1,6-bisphosphate This option is incorrect. Option 3) Pyruvic acid This option is incorrect. Option 4) Acetyl CoA This option is correct.
Medical
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The process which makes major difference between C3 and C4 plants is

  • Option 1)

    glycolysis

  • Option 2)

    Calvin cycle

  • Option 3)

    photorespiration

  • Option 4)

    respiration

 
As learnt in Photorespiration - A process in plant metabolism where enzyme RuBisCO oxygenates RuBP, causing some of the energy produced by photosynthesis to be wasted. - wherein O2 enters Calvin cycle instead of Co2  this results in reduced rate of photosynthesis.       Calvin cycle - Involves CO2 fixation in the presence of ATP and NADPH and its conversion to glucose, through a series of...
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