Study of the normal functioning of plants and plant cells

learn more… | top users | synonyms

25
votes
4answers
3k views

Do plants produce any heat?

Many plants (e.g. roses, palms) can be protected from frost during the winter if shielded with an appropriate coat that can be bought in garden shops. Do plants produce any heat that can be kept ...
24
votes
1answer
775 views

How long will a vegetable live for after being harvested?

I understand this might depend on the types of vegetables, but is there an average or studied specifics? Does it die immediately? Is there a way to precisely diagnose death in plants? If so, what are ...
20
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 ...
15
votes
3answers
505 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 ...
13
votes
2answers
4k views

How will rising carbon dioxide levels in the troposphere affect photosynthetic producers?

Much discussion has been had about the affects of climate change on plantlife, but how will rising carbon dioxide concentrations affect the photosynthetic process itself? Since CO₂ is a reagent in ...
13
votes
1answer
3k views

How does a plant grow before photosynthesis is possible?

During photosynthesis, a plant translates CO2, water and light into O2. I assume the carbon C is further used for the growing process. I wonder how the plant grows before the time where photosynthesis ...
13
votes
3answers
288 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 ...
13
votes
2answers
1k 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 ...
13
votes
1answer
105 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
3answers
189 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 ...
11
votes
2answers
545 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 ...
10
votes
2answers
127 views

Why do cucurbits produce so much fluid when their stems are cut?

When carrying out some germination tests on species in the Cucurbitaceae, I notice that young plants of this family produce a lot of clear fluid when they are dissected. Most plants I dissect do not ...
9
votes
1answer
194 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 ...
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 ...
9
votes
1answer
1k views

Why do some plant species have lobed leaves, while similar species in the same habitat don't?

Some plants have lobed leaves, like the English oak (Quercus robur), while other plants growing the same deciduous woodland habitats, and very often growing alongside oaks, such as the European beech ...
9
votes
1answer
1k views

What's the effect of oxygen deficit on plants?

As I know all cells require oxygen. So my question is how efficiently can plants operate in no-oxygen atmosphere? Do all plants produce enough oxygen for themselves? Can they consume their own oxygen ...
9
votes
1answer
434 views

Why can you graft two unrelated cacti successfully, but you cannot do this on garden trees?

Any cactus can be grafted onto any other cactus, and even the most unlike of them grow together. My latest graft was a Schlumbergera truncata scion on an Opuntia microdasys rootstock. This kind of ...
9
votes
2answers
2k views

If I graft two trees together while young, will they grow as one plant?

If I were to graft two apple saplings together, by bending the tops toward each other and lashing them together, will the plants grow as one and benefit from one another, or will they be fighting each ...
9
votes
1answer
296 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 ...
9
votes
1answer
119 views

How would a warm winter affect maple sap production?

The past winter (2011-2012) was warmer than usual. Trees are normally tapped in late February when the daily maximum temperature goes above freezing. However, assuming that there have been ...
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 ...
8
votes
5answers
793 views

Is it possible to genetically modify a plant at home?

Would I be able to genetically modify a plant at home? What equipment will be necessary? I think it might be a fun change from the 'norm' of regular hybridisation, to try some inter-family gene ...
8
votes
1answer
164 views

How did these apples grow together?

I came through this pic while scrolling through facebook, and it was a bit strange to me. As far as I know apples have a corymbose type of inflorescence, in which a single pedicel ends in a single ...
8
votes
1answer
705 views

If the xylem of a woody plant is composed of dead tissue, how does sapwood become heartwood?

If the xylem of a tree is composed entirely of dead tissue, then that means the sapwood is dead. If so, how does it transform into heartwood, and what starts the process?
8
votes
1answer
201 views

What is the maximum potential sucrose concentration of plant sap? What keeps plants below this potential?

I am interested in identifying the maximum potential dissolved sucrose (%w/w) that plant sap could have, and which (biological, physical, chemical) factors constrain the observed sucrose ...
7
votes
2answers
485 views

How do white Caladiums perform enough photosynthesis to support their mass?

In some white caladiums, there is less than a square inch of green space spread over the whole leaf. How do these plants perform the photosynthesis necessary to support the large leaves, the roots, ...
7
votes
2answers
2k 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 ...
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 ...
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 ...
7
votes
1answer
213 views

Compare and contrast “Rubisco activity” and “assimilation rate” (is there a difference, and if so, what is it)?

I am confused about the variable "RuBisCO activity". How is it measured, and is it any different from the net assimilation rate? Based on some background reading (e.g. Kling, 2008; Lambers et al ...
7
votes
1answer
238 views

How do plants 'tell time' for circadian rhythms based on a ~24 cycle?

I've read that many plants have some sort of circadian rhythm where they perform a certain action on a cycle of about 24 hours, like the mimosa plant opening and closing its leaves. Obviously this is ...
6
votes
1answer
638 views

How does water move throughout plants?

I haven't yet found a decent explanation for how water moves throughout plants. It does seem to travel more efficiently upward than out or down. Why is that? How does it travel through the plant?
6
votes
1answer
62 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 ...
6
votes
3answers
608 views

Is there any kind of immortality in plants?

I asked a question about immortality of hydra and learned good things about senescence. Now I would like to know about immortality in plants, if there is some kind of immortality in plants and how ...
6
votes
1answer
973 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?
6
votes
1answer
616 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 ...
6
votes
1answer
322 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 ...
6
votes
1answer
510 views

Regulation in plants bearing cleistogamous and chasmogamous flowers

In most plants bearing cleistogamous flowers, chasmogamous flowers are also borne by the plants. For example, Viola, Oxalis and Commelina contain both these kinds of flowers.( I am unaware of a ...
5
votes
1answer
363 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 ...
5
votes
1answer
221 views

Why dont “growing degree days” have units of degrees Celsius (or do they)?

From Wikipedia: Growing degree days (GDD), also called growing degree units (GDUs), are a heuristic tool in phenology. GDD are a measure of heat accumulation used by horticulturists, gardeners, ...
5
votes
2answers
110 views

Can you tell the sex of a white willow when it's not flowering?

Can you tell whether a salix alba tree will produce male flowers or female flowers by looking at it, touching it or generally using your unaided senses? If not, is there any way to do that without ...
5
votes
1answer
86 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 ...
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 ...
5
votes
1answer
154 views

Measuring algae growth or death

My daughter (10th grade) is doing a science fair project on the toxicity of triclosan for the algae Selenastrum capricornutum. She is wondering the best way to measure the effect, given the limited ...
5
votes
1answer
755 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 ...
5
votes
1answer
198 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
74 views

Gender and age-specific mutation rate in plants

Background General concept According to Cochran and Harpending (2013), mothers transmits on average a number $x$ of new mutations to their offspring. This number $x$ is independent of the age of the ...
5
votes
1answer
115 views

Why does wood become darker when it ages?

I have lots of pieces of pine furniture which have different colours depending on how old they are. So, I just wondered why that is. I guess it has something to do with structures and chemical ...
5
votes
1answer
55 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?
4
votes
2answers
870 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 ...