The study of plant life; e.g. angiosperms, gymnosperms, bryophytes, pteridophytes, and algae.

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151 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 ...
6
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1answer
65 views

What mechanisms tell temperate trees when to drop leaves?

I've been looking around and cannot find a definite answer on what it is that tells trees to change their metabolism and drop leaves. I see that such activity is called Deciduous. What interests me ...
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3answers
316 views

Why are there ecosystems?

Why would things self-organize in such a manner? I'm a mathematician and I have no baggage in ecology or biology. If the question is too broad maybe someone can point me to formal sources where this ...
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4answers
780 views

Why we have no enzyme to digest cellulose?

As we know, cellulose is the most abundant polysaccharide in nature. Why don't we have any enzyme to digest cellulose?
5
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2answers
87 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
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1answer
76 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 ...
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1answer
1k 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 ...
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1answer
587 views

Does cooking or ripening reduce the concentration of solanine in nightshade?

I recall a story from one of my Botany professors where he encountered a woman picking Solanum dulcamara (nightshade) berries. When he asked her what she was doing with them, she responded that her ...
5
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1answer
115 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
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1answer
298 views

How do individual plants adapt to changes in temperature?

If you grow a plant from seed in your nice warm house, then plant it out in your temperate garden, it will stop growing for a while, possibly die, and if not, subsequently resume growth. Standard ...
5
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174 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
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1answer
59 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
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1answer
45 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?
5
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44 views

How are Raunkiær's plant life forms viewed today?

At the beginning of the 20th century, Raunkiær proposed a typology of plant life-forms based on where they bear their buds, roughly as: cryptophytes: belowground hemicryptophytes: at the surface ...
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1answer
59 views

Shade-loving Plants

In shade-loving plants, the light compensation point is reached at low irradiance because: A. Leaves have more chlorophyll per reaction center B. These plants have greatly reduced respiration rates ...
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2answers
89 views

Is it possible to grow any kind of plant soilless (hydroponics)?

Hydroponics is a subset of hydroculture and is a method of growing plants using mineral nutrient solutions, in water, without soil. [wikipedia] My question is if is it possible to grow any kind of ...
4
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1answer
51 views

How much cost would artificial pollination add to common products (fruits etc.)?

I've read about ecosystem services and their possible valuation - statements like "honeybee pollination service in the US is worth 1.6 billion dollars". Is data available on how this would affect the ...
4
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2answers
187 views

Why is the floral biodiversity of grazed grassland higher than that of mown grassland?

I have collected some data to compare the biodiversity of a field in which the plagioclimax is maintained by machine mowing with a field in which the plagioclimax is maintained by sheep grazing. What ...
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2answers
1k 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 ...
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1answer
271 views

What is the largest perennial herbaceous plant?

What is the largest perennial herbaceous plant? My guess would be some kind of banana or bamboo.
4
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1answer
59 views

Sexual Differentiation in Monoecious plants with unisexual flowers

In monoecious plants having unisexual flowers (eg Zea Mays, Ricinus Communis etc), there must be some mechanism as to produce two sexually distinct flowers from the same genotype. Since both the type ...
4
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1answer
76 views

Function of papain in papaya

I know that papain is a proteolytic enzyme present in papaya. It is often used to tenderise meat. What is the function of papain in papaya? Is papain sweet? Does it function as an antibiotic?
4
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2answers
113 views

Plant identification?

Can anyone identify the plant below? It's in a backyard in Pennsylvania, and the photo was taken today.
4
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1answer
8k views

What factors affect the rate of transpiration in plant leaves?

I'm trying to get my head around factors which affect transpiration in leaves. For example, how would applying petroleum jelly to the surface of plant leaves affect their rate of transpiration? I ...
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0answers
65 views

What controls leaf senescence in deciduous tree species, and how can I predict it?

If I want to predict litterfall, what data do I need to collect, and what statistical model might I use? For example, I might use the following coding to record phenological stage every other day, or ...
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0answers
39 views

Serological assays not detecting native proteins

Is there anyone out there who has done much work with serological assays? We have antiserum for a manufactured viral protein but no luck so far getting it to detect native protein (unless today's ...
3
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1answer
296 views

Family tree for edible plants?

I am looking for a family tree for plants, particularly veg / herbs / fruit. Something similar to: If it could be slightly less technical than all the Latin ...
3
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2answers
68 views

What chemical or biochemical agents do plants use to inhibit each other's growth?

As I just learned, allelopathy is the action by which plants regulate the growth of other nearby plants. I have hear of ethylene is a general signal for growth and fruit ripening in particular, but ...
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2answers
54 views

How common is bacterial mediated transformation? In plants? In animal cells?

The most common method to transform plants is by soaking plant tissue in cultures of agrobacteria (this is not their current classification) which transfer DNA into the plants. Is lateral gene ...
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2answers
261 views

Why do plants' leaves become enlarged in low light areas?

Why do almost all plants in shade have a smaller stem structure and larger leaf than that same species grown in a well lit, sunny area?
3
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1answer
52 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.
3
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1answer
23 views

Seed Dormancy and Seed Transportation

My textbook says "As the seed matures it loses water and enter dormancy". I am confused as to whether this happens before the seeds are transported or after, and as to how seeds know to become dormant ...
3
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1answer
191 views

When happens when pollen grains land on the a part other than the stigma of a flower of the same species?

When happens when pollen grains land on the a part other than the stigma of a flower of the same species? Would the pollen be transported to the stigma or would it just sit where it landed and nothing ...
3
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1answer
64 views

Sporophyte and gametophyte

My textbook says that in both groups of seedless plants (vascular plants, non-vascular plants) the gametophyte is a free-living plant, independent of the sporophyte. I don't understand this statement ...
3
votes
1answer
85 views

Plant a whole fruit or only seeds?

I'm trying to figure out whether it is better for the plant to reproduce by planting its whole fruits with seeds inside them, or picking the seeds out and planting them without the fruit. In my case ...
3
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1answer
154 views

If only dicots have pith, what is the foam in the middle of cornstalks?

I've heard that the only plants that have pith are dicots, because of the shape of their vascular bundle. If that is true, what is the foam inside of the corn plants, which are monocots?
3
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1answer
78 views

What are these stars in my microscopic image?

I see this very curious patterns on the sun-facing side of a jasmine (probably) leaf - visible with a makeshift microscope (about 50x) What are them? Pores? Are there other plants with similar ...
3
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1answer
123 views

Has synthetic biology created new plants or animals as of 2013?

I've seen a Ted.com talk where the speaker suggests that modern science can create new micro organisms, like bacteria with a pre- defined new set of traits. But has anyone create a new species of ...
3
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1answer
536 views

Does photosynthesis require only direct sunlight

I have learned throughout my basic science classes in high school that in the process of photosynthesis, plants absorb sunlight & produce food. They use carbon dioxide & water vapour. My ...
3
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1answer
84 views

Why seeds won't sprout given excess water?

What would cause a seed to not sprout despite showing signs of germination given excess water? Oxygen, temperature, and light were sufficient for germination and sprouting in seeds of a slightly ...
3
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1answer
23 views

Mutation in axillary buds of trees overcoming self-incompatability?

I seem to recall from either reading or lecture that there have been instances of trees that are self-incompatible accumulating enough mutations in an axillary bud that the resulting branch was able ...
3
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2answers
39 views

Why do humans circulate monosaccharides instead of disaccharides as in plants?

Plants transport food mostly in the form of disaccharides like sucrose but humans transport them in the form of a monosaccharide - glucose. What is the reason behind this ?
3
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1answer
56 views

H2S as a source of electrons for plants

The first electron source for plants was H2S, but now most modern plants use H2O as an electron source. What is the advantage of using H2O instead of H2S?
3
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1answer
58 views

What happens if we continuously stimulate a mimosa plant?

I know there is some mechanism in humans by which we start to ignore a certain stimuli if it persists for a long time (e.g., we don't feel our shoes all the time !). Can the same thing happen in ...
3
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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 ...
3
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0answers
58 views

Are mature trees as susceptible to mutation from exposure to radiation as seedlings?

If a plant, say a ficus or a teak, as a sapling were exposed to radiation, and a tree of the same species were present at the same distance, which of the two would be more likely to mutate?
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2answers
2k 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 ...
2
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2answers
136 views

Why are there so many medicinal plants?

Here is wikipedia page containing a list of plants used in herbal medicine. One might first want to argue that many of them actually do not have any medicinal/beneficial effect on heatlth. I think we ...
2
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2answers
134 views

Filamentous algae - what exactly am I looking at?

I have just taken some images with my light microscope at 400x of (what I think is) some form of filamentous algae from a local pond. Now, I think I am looking at a single cell (centre) with some ...
2
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2answers
132 views

Why doesn't human consumption of plants cause infectious diseases the way consumption of animals can?

At first I want to clarify that I do know that there are naturally poisonous plants and plants that can hold radioactive stuff or toxic material from the environment. What I mean by "diseases" (I ...