Skip to main content

Questions tagged [plant-physiology]

Study of the normal functioning of plants and plant cells

132 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
14 votes
1 answer
219 views

What actually kills a plant that requires winter dormancy if it is kept indoors all year?

In bonsai practice, beginners will commonly purchase a juniper (often Juniperus procumbens 'Nana'), which is an outdoor tree, and keep it inside all year. The tree invariably dies. It is commonly ...
cape1232's user avatar
  • 249
5 votes
0 answers
1k views

Explanation of the results of Warburg's Flashing Light experiment?

Between 1919 and 1920† Warburg obtained a higher rate of photosynthesis in Chlorella, exposed to rapid alternating periods of light and darkness, than when exposed to constant illumination. I would ...
jyoti proy's user avatar
4 votes
0 answers
63 views

What is a good approximate functional form for an equation relating plant growth to sunlight?

Question is in the title. I've got daily measurements of daily mean shortwave radiation at the surface, and annual measurements of plant growth (some measure, be it height or biomass or something). ...
generic_user's user avatar
4 votes
0 answers
2k views

Pits and Pores in Vascular Tissue

What purpose is served by the pits and pores in xylem and phloem cells? I cant find what purpose that these components serve in the vascular tissues in plants
Victoria's user avatar
4 votes
0 answers
849 views

What metabolic processes do dormant and ungerminated seeds carry out?

What metabolic processes does a dormant embryo in a seed carry out? Seeds will not germinate, either because of a lack of favourable conditions, seed hibernation, or because of a genetically pre-...
stochastic13's user avatar
  • 4,689
3 votes
0 answers
142 views

Why do sieve elements need to be alive

I am studying high school biology and I got these two pieces of information in khan academy and wikipedia: Sieve elements in phloem are living cells because the translocation includes active ...
aaa's user avatar
  • 31
3 votes
0 answers
34 views

How does a heat-ratio sap flow sensor work and how invasive is it?

The Gizmodo article Undead Tree Stump Is Being Kept Alive by Neighboring Trees says: Leuzinger and Bader stumbled upon the stump while out for a hike. The woody stub caught their eye because callus ...
uhoh's user avatar
  • 5,598
3 votes
0 answers
210 views

Regulation of LBD33 genes Arabidopsis. If LBD 33 gene is up-regulated by auxin then why does expression decrease when increasing auxin concentration?

I have a question regarding the regulation of lateral boundary domain genes in Arabidopsis (specifically LBD33). I am an undergraduate student trying to understand the results of a lab where I measure ...
jack's user avatar
  • 221
3 votes
0 answers
103 views

What amount of light energy is required to produce one O2 molecule? How about one molecule of NADPH?

I know that for each O2 molecule, a total of 8 photons are required (4 per photosystem). Would the amount of light energy required be E=hc/wavelength using 680 and 700? Or would the energy from the ...
ro_the_electron's user avatar
3 votes
0 answers
137 views

Can photorespiration do any good?

When CO2-levels are to low plants start to photorespirate instead of photosynthesise. This cost them losses in energy, and adds CO2 to the atmosphere instead of O2. I wonder if the photorespiration ...
Hannah's user avatar
  • 193
3 votes
0 answers
389 views

How did fig tree take root in trunk of palm tree?

Please see pictures below. I never saw anything like this. Do the roots of the fig tree penetrate the trunk of the palm tree? Is there a symbiotic relationship between the two?
0tyranny0poverty's user avatar
3 votes
0 answers
31 views

Why do certain ferns have roughened spore surface?

Ferns such as Anemia phyllitidis, Blotiella lindeniana, Ctenitis hirta, Cystopterix fragilis, Hemionitis palmata and many others have roughened splity spore surface. I ask, why is it evolutionary so?...
Kryštof Chytrý's user avatar
3 votes
0 answers
505 views

Why does a broad-leaved evergreen (Mahonia aquifolium) has red leaves?

To my knowledge, oregon grape (Mahonia aquifolium) is purportedly an evergreen shrub? Deciduous broadleaf plants lose their leaves in autumn usually and before that as the leaves die they oxidize and ...
Jaguar Domingo's user avatar
3 votes
0 answers
463 views

Can Galactose be synthesized with photosynthesis?

I know that galactose can be found in sugar beets and some gums so I thought plants could synthesize galactose but in my book the answer to the question "Which of these can be synthesized with ...
Mertcan Ekiz's user avatar
3 votes
0 answers
433 views

Is there a standard definition for plant "maturity"?

Is there a species-agnostic metric for identifying plant maturity? There seems to be plenty of literature defining life-history stages for specific crops, but it is not clear if there is a generic ...
Abe's user avatar
  • 716
2 votes
0 answers
26 views

Is there always a leaf(s) attatched to an auxillary bud?

I'm trying to create a 3D functional-structural plant model and I need to establish some axioms. Is it guaranteed or extremely likely that where auxiliary bud forms there's a leaf(s) attached? That's ...
Lambda's user avatar
  • 21
2 votes
0 answers
35 views

How much sunlight is required for photosynthesis to peak?

I've read that photosynthesis peaks at some point over light intensities https://en.wikipedia.org/wiki/PI_curve According to https://www.bbc.co.uk/bitesize/guides/z9pjrwx/revision/5 suggests At very ...
John M.'s user avatar
  • 121
2 votes
0 answers
44 views

What causes the distinct color change in matured leaves in some plants?

Maybe that color change is caused by lower chlorophyll concentration in younger leaves' cells, or chlorophyll a to b ratio differs between younger and older leaves. All I could find is that the ...
Damocle Damoclev's user avatar
2 votes
0 answers
123 views

Regarding secondary growth in dicotyledonous angiosperms

I had read that (and as this image shows) the secondary and primary phloem eventually get crushed due to the repeated division of cells forming the secondary xylem, during secondary growth in ...
m-Xylene's user avatar
  • 215
2 votes
0 answers
40 views

Spatial sequence of autumn leave colouring: top to bottom

Leave colours on trees seem to vary on the same tree from top to bottom. Leaves higher up are already further ahead in the shedding process. What's the reason for this tempero-spatial gradient?
Cornelius Roemer's user avatar
2 votes
0 answers
57 views

A single leaf in a very strange air current / wind?

Here is my eight years old movie where I have pictured a single leaf moving in a very weird way: https://www.youtube.com/watch?v=sCjvgdfNCjU Can someone explain me what is depicted in this movie (...
trejder's user avatar
  • 323
2 votes
0 answers
50 views

Has anyone confirmed Darwin's theory that nectar began as something "injurious" to sap?

In "Origin of Species", Darwin says (I have added bold for emphasis): Certain plants excrete sweet juice, apparently for the sake of eliminating something injurious from the sap: this is effected,...
Greg Thatcher's user avatar
2 votes
0 answers
454 views

How does heat stress kill plants?

It is known that many plants typically die when exposed to temperatures of 40 to 50°C (I believe, these figures relate to exposure times of ~1–2 hours). When a plant is heated, what is the mode of ...
Merin's user avatar
  • 21
2 votes
0 answers
27 views

Why does the iron content differ in different species on seeds?

Iron can be affected by pH of the soil but why does each species actually have a different iron content. What causes it? What genes cause it?
lara's user avatar
  • 21
2 votes
0 answers
319 views

Why don't acacia trees prefer increasing tannin levels in their leaves rather than leaving them high?

According to this article, the Acacia tree has a chemical defence system which leads to the release of ethylene in the surroundings when a herbivore grazes on it. This leads to an increase in tannin ...
Polisetty's user avatar
  • 3,687
2 votes
0 answers
16 views

Fixing plant leaf tissue for tensile tests

I'm a new master's student in mechanical engineering, and I'm researching crop biomechanics. We need to do some tensile tests on samples of corn stalk sheath, which involves securely and evenly ...
Ryan Larson's user avatar
2 votes
0 answers
143 views

Effect of high temperatures on plant stomata

My biology textbook states that stomatal closure occurs at high temperatures to avoid water loss. Another stackexchange thread I can find (What is the effect of temperature and carbon dioxide on the ...
Matt Whitelock's user avatar
2 votes
0 answers
686 views

Can light destroy auxin?

In my biology textbook, it says that plants grow towards light because auxin is laterally transferred from the light side to the shaded side, so more auxin stimulates growth and hence the plant bends ...
Sharon's user avatar
  • 125
2 votes
0 answers
322 views

Why do plants produce and store both amylose and amylopectin?

Since both forms of starch has its primary purpose of storing glucose and hence releasing energy, why are there 2 variations of this sugar? Is it possible for an organism to contain/depend only on 1 ...
user35897's user avatar
  • 1,260
2 votes
0 answers
250 views

Are there special pairs present in the RC of both photosystem I and photosystem II?

I am confused regarding the existence of special pair (primarily regarding PS2). Do both, P680 and P700 have special pair? I have checked various sources online and have come across conflicting ...
Lifeisafartinthewind's user avatar
2 votes
0 answers
83 views

Why does abnormal mitosis takes place in the cells of tapetum?

I know that the tapetal cells present in the anther are binucleate. I also know this means that after karyokinesis the cell does not divide itself and instead form a syncytium. This occurs due to ...
Esha Mukhopadhyay's user avatar
2 votes
0 answers
227 views

Why do basil leaves turn black?

I notice that when I buy basil it is fresh and green in the store, but when I take it home it wilts and turns black within 24 hours. Why does it do this?
Imprisoned Rhesus's user avatar
2 votes
0 answers
37 views

What is a rough estimate of CO₂ saturation for high-yield or high growth rate plants?

Naturally, plants have individual photosynthesis capacities, but it would still be interesting to get a general picture of CO2 saturation levels for some common cultures. Where lies the optimal yield, ...
Henrik Erlandsson's user avatar
2 votes
0 answers
516 views

Is there a plant particularly suitable for absorbing Hydrogen Sulfide

I live in an area with some open sewers and in the morning I can usually can smell the gas inside my house. There are many plants like snake plant which improve indoor air quality but I was ...
Holysmoke's user avatar
2 votes
0 answers
42 views

Which biosynthetic pathways take place in the plastid and were are they located?

I know that the isoprenoid, jasmonate, glucosinolate, fatty acids, chlorophyll, starch, and aromatic amino acid syntheses are located in the plastid. But I don't know if they are located in the ...
Oli4's user avatar
  • 174
2 votes
0 answers
59 views

Rosemary room temperature at winter

I consistently read in non-scientific resources that I have to put my rosemary to low temperature (about 10°C) in winter (unless I don't want it to freeze). I googled, but I fail to find a scientific ...
inf3rno's user avatar
  • 4,460
2 votes
0 answers
3k views

Is it possible to simulate the effects of high altitudes for plants?

Note- I considered asking this on gardening.stackexchange.com but i believe it is better suited for this site since it deals with more complicated material. As I understand it, certain plants (...
Nick's user avatar
  • 203
1 vote
0 answers
32 views

tools and techniques for determining nutrient status in plants

I am interested in tools and techniques, both commercial and academic, developed for determining nutrient status and identifying limiting nutrients in growing plants. My specific interest is in ...
sanjihan's user avatar
  • 355
1 vote
0 answers
40 views

Water transport to the Shoot apical meristem in a seedling

I am familiar with how plants transport water from the roots to leaves. Specifically, Water evaporates from the leaf surface, generating a negative pressure gradient which pulls water up from the root....
Giraffes4thewin's user avatar
1 vote
0 answers
23 views

Do Glycosides in plant seeds serve some other function than protecting the seeds?

Many plants have toxins like glycosides in the seeds and I think other parts of the plant and the accepted reason for this I believe is to discourage animals that ingest the seeds from digesting ...
releseabe's user avatar
  • 335
1 vote
0 answers
40 views

Is a plant's own compost better for the plant?

Does it make a difference if a plant is composted and used for its own compost ? Meaning, let's say there is a plant "X" (example Cucumber) Would it grow better if the compost was made from ...
Anand Sunderraman's user avatar
1 vote
0 answers
10 views

Does lower stomatal conductance of water influenced by elevated CO2 decrease overall evapotranspiration?

From what I understand, elevated CO2 levels decrease the stomatal conductance of water in plants. What I remember from irrigation sciences, higher temperatures should be more demanding on ...
Luckasino's user avatar
  • 155
1 vote
0 answers
38 views

Photolysis of water

Photolysis of water releases $\text{O}_2$, $\text{H}^+$ ions and $\text{e}^-$. $\text{Mn}$ in the $\text{O}_2$ evolving complex also produces $\text{e}^-$. What provides $\text{e}^-$ to P680:$\text{Mn}...
Asha Kiran Lima's user avatar
1 vote
0 answers
773 views

Calculation of solute, pressure and water potential

What would be the water potential (Ψw), solute potential (Ψs) and pressure potential (Ψp) at equilibrium when a cell with Ψs= – 0.7 MPa and Ψp= 0.7 MPa is placed in a solution with Ψs= – 0.5 MPa? (...
Neerav Singla's user avatar
1 vote
0 answers
74 views

How long can zooxanthellae survive on their own, after being expelled from coral after a bleaching event?

So many sites (and books and journals and such) discuss how long different types of coral can survive without their dinoflagellate algae (zooxanthellae), but... How long can the poor little symbiotic ...
Kurt Hikes's user avatar
1 vote
0 answers
48 views

Does Ethylene Triple response provide any advantage to the Arabidopsis thaliana Etiloated seedling,?

As ethylene has a triple response effect on Arabidopsis thaliana Etiloated seedling- 1 Shortening and thickening of Hypocotyl 2 Exaggerated apical hook 3 Short root According to this site Ethylene ...
Samardeep singh's user avatar
1 vote
0 answers
220 views

The reason behind red drop effect

I was reading about Emersion effect on Wikepedia, I was not able to correlate our current knowledge of photosynthesis with this effect, First red drop effect When Emerson exposed green plants to ...
Samardeep singh's user avatar
1 vote
0 answers
70 views

Can Monsanto's (in)famous hybrid seed crops be cloned/grafted? If not, is there a technical or legal reason?

I understand that the seeds of a crop made from modern-day super hybrids will not, usually, produce the same quality plants in the next generation. Therefore, farmers have to buy new hybrid seeds each ...
Kurt Hikes's user avatar
1 vote
0 answers
15 views

How does a diploid sporophyte form in non-recurrent apomixis?

I came across this definition of non-recurrent apomixis which occurs in angiosperms- In non-recurrent apomixis, both the egg-cell and embryo are haploid and embryo is developed directly from an egg-...
m-Xylene's user avatar
  • 215
1 vote
0 answers
46 views

Is there a known efficiency rate for CO2 capture from ambient air in photosynthesising plants?

When humans take in air to their lungs, we capture about 5% of the total quantity of the air as oxygen (which in turn equals about 24% of the available oxygen in the air) Is there an equivalent rate ...
Amphibio's user avatar
  • 263