Tagged Questions

Study of the normal functioning of plants and plant cells

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8
votes
4answers
1k views

How do trees lift water higher than 10 meters?

The atmosphere pressure is 10 meters of water (approx). This means that it is impossible to lift water higher than 10 meters with vacuum or сapillary action (on Earth, under normal conditions). There ...
5
votes
1answer
615 views

Why do organisms excrete nitrogenous wastes?

All plants and animals excrete nitrogenous wastes in the form of urea, uric acid or ammonia. But isn't that a bit of a waste? I mean, there is a shortage of biologically available oxygen in the ...
3
votes
1answer
57 views

What is the cause of the spots on this leaf?

On a hiking trip to the Alps I found trees whose leaves showed those spots you see on the picture. I am curious about what the cause is. Higher resolution pictures of front and back side.
1
vote
1answer
192 views

What is the recommended PPM when foliar feeding L-amino acids

It is said that L-amino acids such as histidine, methionine, aspartic acid, glutamic acid, asparagine and glutamine can revert plant stomata closure, increase quality of fruits and assist maturity. It ...
2
votes
2answers
3k views

How do plant cell divide without centrioles?

Most plants do not have centrioles , so who does their function ?
6
votes
1answer
913 views

How do lilies sense day and night and open and close their flowers?

We have lots of lily flowers inside our garden. Their flowers are open in day and closed in night. How do lilies sense day and night and open and close their flowers?
2
votes
1answer
449 views

Water potential in plants?

The concept of water potential in plants tries (and succeeds) to explain various movement and transports in plants. I have learnt that it can be though of being composed of various components like the ...
0
votes
1answer
245 views

Confusion regarding photosynthesis and respiration in plants

During 24 hours there is a time in i.e. twilight when plants neither give oxygen nor carbon dioxide why is it so? This also suggests that neither of the two vital processes i.e. respiration or ...
9
votes
1answer
261 views

How do pineapples and lemongrass grow?

You can't plant the leaves, you can't plant the fruit, but, if you plant the part where leaves and fruit meet you will grow a whole pineapple plant. The part of the pineapple where the leaves meet ...
2
votes
1answer
99 views

Electron transport in granal stacks

See paper for distribution of PS-I and PS-II within grana As explained in the above paper, the PS-I complex is primarily located within non-appressed thylakoid region and stroma lamella, while PS-II ...
5
votes
1answer
85 views

Photosynthesis regulation

I read about the regulation of Calvin cycle by thioredoxin which activates key enzymes essentially by converting disulphide linkages on inactive enzymes into sulfhydryls. Another regulatory mechanism ...
4
votes
1answer
80 views

Measuring sugar content of a tree

I would like to grow mushrooms on oak trees I can harvest from my property. I've read that the best results will be when the sap is rising but the tree hasn't budded yet. The mycelium feeds on the ...
0
votes
0answers
233 views

Relationship between biomass and net primary productivity

I want to do validation on simulated net primary productivity. But I don't have measured NPP data, Eddy covariance flux measurement data. I have only field measurement biomass data. So can I directly ...
1
vote
2answers
882 views

What chemicals and structures control the *direction* of plant growth in leaves, stems and roots?

If you want a specific plant, let's say the snap peas I am growing that I bought at Agway. I noticed that they grow towards the light source through the nearby window. Also I think roots work the same ...
0
votes
1answer
153 views

Why does the PR form of phytochrome exist?

I know how it gets converted because PR is more stable and when there is neither red or far red light PFR naturally converts to PR. But what is the point of it? If PFR is the biologically active one ...
6
votes
1answer
60 views

What controls the southern range of willows?

Many willows (Salix spp.) grow in northern states but do not grow in southern states, for example Salix viminalis. What mechanisms control the southern range of temperate hardwoods such as willow? Is ...
3
votes
0answers
107 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 ...
1
vote
1answer
158 views

What part of the cactus photosynthesizes?

In general, plants photosynthesize through their leaves and, to a much lesser extent, through their stems. Cacti, however, have no visible leaves, but instead spines. In what part of the cactus does ...
13
votes
3answers
280 views

Can plants get cancer?

I can't think of any reason why plants wouldn't be able to get cancer, but I've never heard of a plant growing a tumor. I've also never seen a plant with a noticeable abnormal growth. Can plants get ...
1
vote
2answers
119 views

Plants without bacteria? is it theoretically possible?

I know from school, that all live on the Earth need bacteria as low-level "machines" that break down/extract/convert/produce chemical elements and combinations, other high-level organisms needed. But ...
5
votes
1answer
2k views

How does plant grafting work?

Plant grafting is a process whereby a piece of one plant is inserted into another and results in a change of the original plant. For example, grafting a piece of a lemon tree into a bitter orange tree ...
8
votes
2answers
507 views

Do plant-animal cross races exist?

Plants and animals have the following distinct properties: Plants live from solar energy by photosynthesis, they use solar energy to make sugar and oxygen out of carbon dioxide, which gives them ...
9
votes
2answers
1k views

Does Sansevieria trifasciata really absorb Carbon Dioxide at night?

There's a claim that Sansevieria trifasciata (Mother-in-law’s Tongue) generates oxygen from carbon dioxide during the night. This seems surprising to me: that process requires energy; plants generate ...
6
votes
3answers
563 views

Is there any kind of immortality in plants?

I asked a question about immortality of hydra and leaned good things about senescence. Now I like to know about immortality signs in plants. If there is some kind of immortality in plants its process ...
2
votes
1answer
44 views

What's the simplest set-up to demonstrate soiless plant growth to middle school students?

I'm looking for a simple, inexpensive way to demonstrate that soil is not needed for plant growth to middle school students. I plan to germinate bean seeds in cotton, but where do I take it from ...
1
vote
1answer
31 views

Can a plant be induced to accelerate transpiration?

Just what the title states. I wonder whether it is possible to fire a chemical switch - sort-of like injecting adrenaline in a human, to accelerate a particular process in a plant. For example, ...
1
vote
1answer
55 views

Arabidopsis thaliana RCSB active site gene mutant

I'm looking for an Arabidopsis thaliana gene listed in RCSB with a clear mode of function and active site. In addition it needs to have an obvious phenotype when knocked out like severely retarded ...
3
votes
1answer
80 views

How can GMO contaminate biologic plants?

Let consider two use cases : I am the only farmer within a 200km radius. I first grow GMO plants. A few cycles later I decide to grow bio plants, so I uproot all of the GMO plants and plant fresh ...
2
votes
2answers
4k views

How do trees use Adhesion and Cohesion to move water against gravity?

I have an AP Bio class where I have to name 3 properties of water and I chose adhesion and cohesion for one of them. I'm having trouble finding out how exactly trees use adhesion and cohesion to move ...
3
votes
0answers
107 views

How does a plant decide when to grow a branch? [duplicate]

As a plant grows, at some point the first branch forms. As it continues, branches grow new branches, and so on, in a seemingly random way. Is it random, or is it driven by the environment (heat or ...
7
votes
2answers
84 views

Exactly which amino acids are phosphorylated in higher plants during state transitions?

I know it is usually stated as the threonine residue near the N-terminus of either light harvesting complex (lhc) b1 or lhcb2, but if this is somehow lost, say in a mutant, is the system flexible ...
4
votes
2answers
780 views

What is the effect of a pure-oxygen environment on a plant?

Just read What's the effect of oxygen deficit on plants? ; and wondered whether the opposite would have any effect on a plant. That is to say, if a potted plant were placed under a bell-jar and ...
9
votes
1answer
186 views

Black bumps on the cut surface of an avocado

I cut an underripe avocado in half and put half of it, without the pit but with the peel, in the refrigerator. A day later, I see very small black bumps along the cut surface. What are they? What ...
3
votes
1answer
95 views

Would a plant survive if it was watered using hard-water?

Hard water is water with high mineral/salt content. I'm told that a potted plant watered with a salt solution dries out sooner or later. Is this true? If so, would a plant survive if watered using ...
4
votes
1answer
284 views

How does a plant cutting develop roots?

Please correct me if my understanding is incorrect; I understand branch/stem, and root are composed of different types of cells. Yet in some plants (e.g. rose, bougainvillea) a cutting from the stem ...
2
votes
1answer
294 views

Will fruit/seed of a bonsai yield another bonsai plant/tree?

With practice one can create a bonsai; no complicated modification of the DNA in a high-end lab required. The bonsai will even beget bonsai fruit. What I am curious about is - if such bonsai fruit ...
1
vote
0answers
43 views

Where can I find approximate rates of sequestration of CO₂ for different species of algae?

For a study, I want to compare the rates of CO₂ sequestration and fixation of a few different species of algae. I could not find any data on the sequestration rates. Any pointers to where I can find ...
5
votes
1answer
348 views

Do all plants photosynthesize with equal efficiency?

Just what the title states. Given identical, necessary and favourable conditions (Probably nutrients, humidity, and light but what I mean is all necessary requirements are fulfilled) - Is ...
6
votes
1answer
305 views

Can I estimate leaf temperature from air temperature? What other information would be required?

Physiological measurements such as respiration rate and assimilation rate depend on temperature. Most papers report tissue temperature (e.g. leaf temperature for leaf measurements), although some ...
4
votes
2answers
2k views

Online course on Plant Taxonomy and Physiology

After following a course in Permaculture, I realised that if I want to get serious about it, I need to be able to distinguish plants. So I am looking for an online Video course on Plant Taxonomy and ...
7
votes
2answers
1k views

Why animals can move and plants cannot in general?

To clarify, I think the answer should be able to explain: What are animals? What are plants? What's the difference between animals and plants (How do biologists differentiate them, if they ...
15
votes
3answers
468 views

Why do some trees have a life span, while some don't?

I have heard that there is no limit on the growth of trees, but then why do some trees, such as boxelders and poplars, tend to live shorter than redwoods, for example? Some advertisements for improved ...
5
votes
1answer
195 views

How do plants intake minerals through their leaves?

How do plants intake the fertilizer when it is sprayed all over the leaf surface as a foliar feed?
5
votes
1answer
54 views

Why are some plants frost tender?

Why do some plants have the ability to stand frost, while others can't? Does it have to do with the size of the water vacuoles in the plant cells?
17
votes
4answers
1k views

How do trees manage to grow equally in all directions?

I was walking down a road with these beautifully huge trees when this question occurred to me. Large trees with many thick branches have to grow equally in all directions, or they would tip over. Is ...
11
votes
1answer
98 views

Does a theory exist for the formation of thylakoid structure?

I'm interested in how the structure of the thylakoid forms into its characteristic highly rugose stacks of grana. What causes the thylakoid to invaginate and self-associate, albeit with what appear to ...
12
votes
2answers
986 views

How does a tree trunk sprout and grow after being cut?

After I cut trees into logs and remove the branches in winter, they start growing. They sprout out and grow completely normal looking stems and leaves and maintain them all summer. The sprouts mostly ...
12
votes
3answers
175 views

Why do some fruits have a much wider range of acceptable sizes than others?

Some fruits such as pumpkins can grow to be 100 lbs. Under different conditions, the same variety of pumpkin can produce a 15 lb. fruit. Both plants are healthy, and look the same except for their ...
6
votes
1answer
548 views

Do immature fruits perform photosynthesis?

Most immature fruits are green: peppers, pine cones, plums, lots of them. I want to know if the green is from chlorophyll in the cells. Do the fruit cells perform photosynthesis? When you cover a ...
7
votes
1answer
1k views

Can any plant regenerate missing tissue?

I have not yet found a plant that, when an insect eats a hole in one of its leaves, it can regenerate the lost tissue. Many plants will grow a new stem if the old one is cut, but it is not a perfect ...