Q&A - Ask Doubts and Get Answers

Sort by :
Clear All
Q

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.

gymnosperms have haploid endosperm....?
@Anupam kanojia Yes Gymnosperms have haploid endosperm as it is formed before fertilization.
IMG_20190303_003648.jpg Choose the incorrect statement •ametophyte of gymnosperm are dioecious, (2) porophyte of gymnosperm are alway heterosporous, (3) Sporophyte of pteridophyte inay or dioecious. (4) Gametophyte of pteridophyte may monoecious or dioecious
@Nishanjali the correct ans of your question is b. Sporophyte of gymnosperms is not always heterosporous. It can be homosporous also in case of dioecious plants. For example, in Cycas we have microspore and megaspores on different sporophytic plants while in Pinus single sporophytic plant bears both microspores and megaspores.  
IMG_20190228_1917532.jpg which tissue system constitutes the bulk of the plant body: 1) epidermal tissue system 2) ground tissue system 3) vascular tissue system 4) Both 1 and 3
@Chinmoy mehta GRound tissue system constitutes bulk of the plant body
mam ,for what we defined term monoecious or dioecious sporophyt or gametophyt
Gametophyte is the gamete bearing stage of a plant while sporophyte is the spore bearing stage of a plant. For example in gymnosperms or angiosperms the tree tht you see are representing a sporophyte on which very reduced type of gametophytes are formed.
in gymnosperm male gametophyt are how many celled
@Nishanjali single celled
A thistle funnel is filled with sucrose solution and kept inverted in a beaker containing water in case the sucrose solution disuses out ,will this equilibrium ever be reached? Kindly explain its a line from Ncert A thistle funnel is filled with sucrose solution and kept inverted in a beaker containing water in case the sucrose solution disuses out ,will this equilibrium ever be reached?
@Manisha one more thing, if the semipermeable membrane is intact then it will not allow passage of sucrose molecules. Sucrose can diffuse only if the membrane is not intact. In case of such a membrane equillibrium can not be reached. So there can be two possibilities if the membrane is intact then equillibrium can be reached and if it is not then equillibrium will not be reached
Screenshot_2019-02-26-22-17-25.png please explain 3and 4options 33. A true breeding plant is a) one that is able to breed on its own b) produced due to cross-pollination among unrelated plants c) near homozygous and produces offspring of its own kind d) always homozygous recessive in its
@Nishanjali true breeding plant means plant which produces same as their parent plant and alleles for these type of organisms are homozygous, True-breeding plants and organisms may express phenotypes that are either homozygous dominant or homozygous recessive. With complete dominance inheritance, dominant phenotypes are expressed and recessive phenotypes are masked in heterozygous individuals,...
What are complementary cells in plant anatomy???
@Drmohamed ashraf Complementary cells are a mass of cells in plants, formed from the cork cambium at the position of the lenticels. It is a group of loosely arranged cells that aid in gaseous exchange through cork.
Q. 4 Apoplastic path for the transport of water in root is through.
but it even passes through the endodermis
can u tell me at which extent it should be mobile aur immobile and overall can we say that it is immbolie if nothing is given about extent??
see it is generally immobile however if the deficiency exceeds a certain threshold it become mobile and start re localising to different parts
and how lactobacilli is used for cheese prepration its mainly used in curd making
While producing cheese, we need to coagulate the milk. Lactobacillus is used for that process. It is used as starter culture.   
Exams
Articles
Questions