A message from our CEO about the future of Stack Overflow and Stack Exchange. Read now.

Questions tagged [plant-physiology]

Study of the normal functioning of plants and plant cells

Filter by
Sorted by
Tagged with
2
votes
2answers
89 views

Is this in vivo or ex vivo?

This question has probably been asked a few times but I get the concept I just dont know how to apply it for this paticular experiment I aim to use cherry tomatoes and determine its glutamate content ...
0
votes
0answers
145 views

What is the molecule responsible of the yellow color of the Agave americana?

Does anybody know what is the molecule responsible of the yellow color at the edges of this plant? I noticed also that the new forming yellow part at the begging stage is soft green until it is ...
2
votes
0answers
399 views

“CO2 is plant food” - What is the actual effect of increased CO2 on plant growth?

A frequent talking point by global warming deniers is that CO2 in the atmosphere is actually beneficial because "CO2 is plant food". I'm a non biologist trying to figure out under what circumstances ...
0
votes
1answer
2k views

What's the highest temperature that algae can survive at?

I know there are a lot of different species of algae and that each one has different environmental tolerances. I've seen data on different species: brown alga Sargassum echinocarpum J. Agardh - grows ...
3
votes
2answers
2k views

Is Valerian extract a diuretic or an antidiuretic?

I am trying to determine if valepotriates (valerian extract) is a diuretic or an antidiuretic. Some individuals take valerian as an herbal supplement for anxiety disorders. Some individuals claim that ...
4
votes
1answer
2k views

Do flowers transpire?

I have googled this out but no where found a satisfactory answer. The definition of transpiration states that it is the evaporative loss of water from the aerial surfaces of the plant but I am really ...
0
votes
1answer
774 views

Explain a transpiration graph

The solution is A, but I think both A and C are correct. For choice C, stomata that protected by hairs will have a greater amount of water vapour around them, hence lower water potential gradient. ...
1
vote
1answer
844 views

Photosynthesis and its subtopics [closed]

Which of the following statements about photosynthesis is true? a. Photosynthesis is an energy consuming process b. The light-dependent reactions produce the energy-rich compounds that are used up ...
0
votes
0answers
167 views

How does an increase in CO2 concentration affect Photosynthesis and Transpiration

I noticed a strange thing in my book. At one place it says that an increase in CO$_2$ concentration in the outside air decreases the rate of transpiration but at the other place it says that an ...
0
votes
2answers
88 views

What is the genetic difference between two cone branches?

As we can see on this larch, male and female cones are sometimes directed to grow on the opposite side of the branch. We were told in school that this mechanism works against self-fertilization. Also ...
4
votes
2answers
188 views

Where do plants obtain the metal ions needed for biological processes?

Enzymes employ metal ions (e.g. Mg, Cr, Mn, Fe, Co, Ni, Cu, Zn) for catalysing certain reactions. Let's consider planting a seed. Where will it obtain these metal ions from? Just from water?
1
vote
1answer
149 views

What are the theoretical and actual (measured) minimum water potentials in plants?

I'm a plant physiology researcher, but water potentials are not really my thing, so I don't have a great grasp on the literature. I'm dealing with water potential data right now though, and it seems ...
1
vote
1answer
324 views

Mechanism by which water flows through xylem

I was doing a Cambridge iGCSE past paper when I came across the question: Describe the mechanism by which water flows through the xylem I thought the correct answer would revolve around the xylem ...
5
votes
1answer
142 views

Do trees have genes for stopping growth?

Do trees have genetically encoded to stop growing at some height, to keep dividing the cells only to a certain amount, or to pump nutritions only till it's advantageous because they've already ...
1
vote
0answers
427 views

How can plants be grown in hydroponics, and yet not handle too much water in soil?

It's pretty much common knowledge that plants planted in pots or soil that doesn't have good drainage can't be watered too much, or they'll "drown". Regardless of what actually happens, experience ...
1
vote
1answer
1k views

Moss Transportation System

In my biology textbook, it says that mosses are avasculer and do not have xylem like spermatophytes. So by what means do mosses transport nutrients ?
0
votes
1answer
10k views

Plasmolysis vs Flaccidity in cells

When is a cell said to be flaccid and when is it called plasmolysed? So far I found that there is a specific relation to osmosis.
1
vote
1answer
331 views

Are there any (chemical) processes occuring inside a seed while it's in a dormant state?

If a seed were in a glass jar without a chance of germination, are there any (chemical) processes occurring inside the seed while it sits there? My intuition tells me no since my understanding of ...
2
votes
0answers
29 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, ...
1
vote
0answers
583 views

Can plant roots absorb dissolved oxygen from water, or do they require actual bubbles in the water?

Plant roots generally require some exposure to air. Deep water culture is a form of hydroponics where plants' roots are left to soak in water. To keep the roots from "suffocating", most online ...
0
votes
0answers
48 views

Is it possible and how could it possible for plant to survive in naked space

I heard that there are fungi could survive on space station in the naked space. I want to know if any plant could be able to do the same How many limitation of plant differ from fungi And could it ...
5
votes
3answers
16k views

Why upper surface of leaves is more green and shiny than the lower one?

I have properly googled this and got various answers. However, those answers do not provide an answer to the "Why" part of my question. Why is it that the upper surface of leaves is more green than ...
1
vote
0answers
188 views

Phototropism or Hydrotropism is a more important factor for trees beside the lakes growing bending to the water?

I see a lot trees beside the lakes are growing bending to the water and I wonder why. After reading this I think it might be a combined effects by: Phototropism: the lake works as a mirror and ...
7
votes
2answers
836 views

Does anyone know the explanation for branches with different flower colors (see picture)?

As you can see in the below picture, there's a branch with white-colored flowers, while the rest of the tree has pink flowers. I googled a number of questions but it is a bit complicated to formulate ...
2
votes
1answer
107 views

Do any plants grow leaves beneath the ground?

We have a pretty common California weed in our yard. When we dig in the ground, we often find small ones there, with green leaves! It's as if they form green leaves before they come to the surface. ...
3
votes
1answer
1k views

Why do fruits have to ripen?

It seems like most fruits that we consume undergo some sort of ripening process either before or after they are picked from the vine, tree, etc. I understand that sugars are released during the ...
3
votes
2answers
193 views

Current scientific theories for evolution of Cucurbita

I'm attempting to find research on scientific theories surrounding the evolution of certain plants, and am unable to find any footing with respect to a certain genus. In this case, I am researching ...
3
votes
1answer
2k views

What is the difference between the glycolate pathway and photorespiration?

I came across the definition of photorespiration as a process that forms CO2 from O2 in the presence of light. However, the CO2 is released only when the plant cell undergoes the conversion of ...
1
vote
0answers
58 views

How does the snail shells' fertilizer compare to regular fertilizers?

May I ask about the quality of the fertilizer derived from the shells and their effectiveness compared to other fertilizers on the market ?
1
vote
0answers
103 views

Relation b/w venation and transpiration

What purpose does reticulate venation in dorsiventral leaf or parallel venation in isobilateral leaf serve? Does it have any relation with unequal transpiration in dorsiventral leaf or equal ...
1
vote
0answers
77 views

Why do the vines change their spinning direction?

Look at the vines holding onto the lattice. The "vine springs" change their spinning direction in the middle. Why? And how do they achieve this? (By the way, what's the name for this plant? Is is ...
3
votes
1answer
140 views

Why it seems that principles of chemistry are not being applied in this biochemical process? [closed]

According to an answer in this question, my concept used below does not apply: In the non-cyclic photophosphorylation, consider splitting of two water molecules, then 4 e- (electrons) and 4 H+ (...
2
votes
2answers
530 views

Ions in Stomatal Opening Mechanism

When a stoma’s guard cells try to swell and open the stomata, they actively pump out protons outside of the cell. This causes a membrane potential, where the inside of the cell is negative with ...
2
votes
1answer
55 views

How can I estimate the CO₂ uptake of a plant?

I would like to make an estimation of the CO2 uptake of plants I cultivate, including, lettuce and aromatic herbs, such as thyme, basil, rosemary. What I want is to end up with a rough indicator for ...
3
votes
1answer
2k views

Why does Citric Acid occur in Citrus fruits?

Why is there so much citric acid in citrus fruits? And how did it evolve i.e. what did it come from? Is it a by-product of the ripening process? Why have citrus fruit evolved a particularly high ...
1
vote
1answer
3k views

Reason for aquatic plant roots

My question is about why aquatic plants have roots. At first they seem a bit superfluous to me because leaves of the plants could just absorb nutrients directly from the water thereby skipping a need ...
1
vote
1answer
1k views

How do CAM plants keep stomata closed by day and open at night?

I understand how plants open stomata, with the H+ ion removal and the resulting K+ ion influx in the guard cells to induce turgor (wikipedia article here), though not how this process relates to ...
7
votes
4answers
11k views

How many ATP molecules are formed?

What is the number of ATP molecules formed during the photosynthetic processes which consume 8 molecules of $\text{H}_2\text{O}$ due to noncyclic electron transport and subsequent photophosphorylation?...
3
votes
1answer
127 views

Determine which seed will germinate first

I recently studied about plant physiology for a test. Strangely, there was this question which I had no idea how to approach. The question is, Which seed will germinate first? a) Castor b) Wheat c)...
8
votes
1answer
195 views

Is there a model perennial plant species?

Most of plant science is conducted on small annual species with short life cycles; predominantly Arabidopsis thaliana, but also a handful of others like Oryza sativa and Medicago truncatula etc. Is ...
5
votes
3answers
454 views

Why do we need to put phosphate fertilizers along with rhizobium?

Isn't phosphorous a macro nutrient? So it should be present in the soil in sufficient quantities... but still we add phosphate. Why?
4
votes
4answers
3k views

Why Isn't mineral transport in xylem multi-directional?

According to our textbook, Xylem transport is only unidirectional while transport through phloem is multi-directional. But minerals are taken up by xylem from the surrounding tissues actively, and ...
3
votes
1answer
917 views

Why would the citrulline content of the watermelon be so high?

Citrulline is a non-proteinogenic amino acid (that is, citrulline is an amino acid that is not coded for in mRNA), and it is an important metabolic intermediate in the Urea Cycle. The Urea Cycle is ...
1
vote
0answers
88 views

Extraction of RNA from algae

I have used a standard protocol (I will give the bibliography below) to extract RNA from an algae (Posidonia) but I have get literally nothing, since I could not even see traces of the two rRNA. I ...
1
vote
0answers
120 views

Why guard cells need to turn malate into postassium malate to become turgid?

According to the Active Potassium Transport Ion concept given by Levitt et.al, stomata open due to turgidity in guard cells. It seems that guard cells turn the starch produced by photosynthesis into ...
1
vote
1answer
763 views

How fast do stomata respond to environmental changes?

How fast does stomatal resistance respond to environmental changes? Correct me if I'm wrong, but I assume that atmospheric humidity would be the fastest changing factor (e.g. rain storm on a dry day, ...
10
votes
1answer
4k views

How fast is water transported from roots to leaves?

I understand basically how water transport from roots to leaves through the xylem works, but I have no idea of the timescales involved. How long does it take for water to get from root tips to leaves?...
2
votes
0answers
488 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 ...
4
votes
1answer
1k views

Do lunar rhythms have really impact on plant growth?

It is commonly known that lunar rhythms have influence on plant growth, and there are even lunar calendars to know when planting, pruning, transplanting, harvesting, etc. I know that the lunar cycles ...
3
votes
1answer
380 views

Needle-like crystals observed in wild-grape wine under microscope. Potentially harmful?

I recently crushed and strained about thirty pounds of wild grapes to ferment into wine. About a month in, I did a visual inspection of the wine under microscope to try and identify some yeast and ...