45

There are at least two separate answers to your question. First, with respect to plants needing CO2, they have evolved to deal with the limited amounts of CO2 normally in the atmosphere. That's really all they need, or "want": adding more doesn't really benefit them. Think of it this way: you need water to live, right? And drink a certain amount of it ...


36

Exhaust gasses from combustion contain many compounds in addition to CO2. Some of them under the right circumstances‡ can be of limited benefit to some plants, but others such as ozone are damaging to all forms of life. Other compounds in vehicle exhaust that are known to cause damage to plants are oxides of sulfur and nitrogen — these react with water to ...


14

Firstly, I don't think it's entirely clear whether the entire premise of the question is correct. I couldn't find any evidence to suggest that plants don't thrive on highways and areas with lots of cars. If anyone has any data on this, I'd be interested in reading it. Some of the answers here seem to be a bit light on evidence. Let's look at some data on ...


12

Back in the early days of climate science, there were some scientists who considered the possibility that increased CO2 production would lead to increased plant growth, and that this in turn would result in keeping the oxygen-carbon dioxide balance more or less stable. This was referred to as the "Gaia hypothesis" and basically revolved around viewing the ...


9

It seems as if nature should absolutely thrive in the middle of highways and nearby, if they get so much nice carbon dioxide from the cars! In fact, some species of plants are likely to thrive from the excess pollution coming from cars, provided they can tolerate the hotter summers and grow quickly enough to take advantage of the higher CO2 levels. ...


8

Ignoring for a moment the other pollutants emitted from car exhaust, increased CO2 levels are warming the planet, through what is called the "greenhouse effect". Photosynthesis is a set of reactions where CO2, water and sunlight are turned into chemical energy used for plant life. However, these reactions only work well in a narrow temperature range. As ...


6

Actually, water is used in the light-dependent portion of photosynthesis, not the Calvin cycle. The added water efficiency doesn't actually relate to water's involvement in chemical processes of photosynthesis at all. Water is instead lost incidentally through stomata when they're opened to allow CO2 into the leaves (see here for explanation). This CO2 IS ...


5

The definition in your first paragraph doesn't match your understanding in the second. If osmotic pressure is high in "A" relative to "B", you would have to apply a physical pressure to "A" to prevent solvent moving from B to A. If there is no such pressure applied, then solvent does move from B to A. The osmotic pressure and physical pressure are separate ...


3

The delay for UVR8 photoactivation seems to be in the range of picoseconds depending on the wavelength: Global analysis in terms of a model of parallel decaying components indicated four lifetimes of 14.7 ps, 370 ps, 1.9 ns, and 5.9 ns. The photodynamics of the Trp ensemble in UVR8 can be summarized as illustrated in Figure 5B. We observe excited state ...


3

The optimum cytoplasmic pH for performing physiological activities in plant cells is a neutral pH of around 7.2 to 7.4. The pH of apoplastic space outside plasma membrane and vacuolar pH is acidic ranging between 5 to 7. The thylakoid lumen is more fluctuating which varies during light / dark cycles and is highly acidic. The mitochondrial compartment and ...


3

The availibity of -OH groups for hydrogen bonding with polar water molecules is reduced in amylose due to its coiled nature (resulting in part by H-bonds between the glucose monomers). Amylopectin is even less soluble due to the additional 1-6 glycosidic bonds on the branch chains, further reducing its H bonding potential and therefore reducing solubility ...


3

This is a really interesting question! It gets to the heart of how photosynthesis works. First, note that whether or not the plant will immediately start producing glucose depends on a variety of factors (what type of plant, what type of light). For example, many succulents undergo CAM photosynthesis (Crassulacean Acid Metabolism) in which light capture ...


2

The second paragraph in the question describes two solutions separated by a semipermeable membrane (a membrane that allows water through, but not anything dissolved in the water). As it says, in those conditions, water will move from the section with low osmotic pressure to the solution with high osmotic pressure. Osmotic pressure, like other colligative ...


1

I think that the potential survival of your seedlings could more likely be credited to your care and management than random genetic mutations. While, of course, DNA mutations happen during cell replication, evolution at the whole-plant scale primarily occurs over the course of generations, not the lifespan of a single plant. You may well be able to get these ...


1

Car exhaust contains a lot more than CO2, including CO - carbon monoxide, which cannot be used by plants and is fatal to humans. (This is why you shouldn't sit in your garage with the door closed and your engine running.) For a full list of the bad stuff, check out this site: https://www.greenlivingtips.com/articles/car-exhaust-chemicals.html


1

We found the following link when search on the quote, the information is cited there: http://gibneyce.com/tree-stats---classics.html Cristina Hubbard, Executive Director Forest Web


1

I don't know much about trees, but I was very skeptical about this post at first. If this web page is correct, then the post is actually not so far-fetched. Trees are amazing. According to the page, the average tree absorbs 10,000 gallons of water and uses 1000 gallons, evaporating the rest. 24 gallons of water contains one pound of dry matter. That means ...


1

Results from the peppermint plants study show that all the peppermint plants contain minor amounts of nicotine before treatment, but the experiments revealed that the plants also incorporate nicotine considerably from the soil as well as from tobacco smoke. These findings demonstrate for the first time that the reported occurrence of nicotine indeed may ...


1

According to recent studies, drought stress does not consistently lead to increases in the pH of xylem sap. One article which discusses interspecies differences is Vit Gloser, et al., "The dynamics of xylem sap pH under drought: a universal response in herbs?," Plant and Soil 409, nos. 1-2 (2016): 259-272. As to what may have prompted the textbook authors ...


1

Depending on molecular weight of amylose and because of its helical structure formed by two macromolecules makes it partly soluble in water. Heating amylose solution leads to formation of colloidal suspension of soluble fraction and remining insoluble higher molecular weight fraction of amylose does not dissolve. On cooling this suspension, certain portion ...


Only top voted, non community-wiki answers of a minimum length are eligible