plants have no neuron...,haven't they.
208274
Why shouldn't caffeine effect plants?  Plants are living, just like humans, plants have hormones that determines its growth development.  Caffeine effects humans, so why shouldn't it effect plants?  \n\nPlants do not have a nervous system because what do plants do?  They just sit.  Due to this, plant growth and development is strictly based on the secretion of different hormones, which is why it takes them so long to respond to the outer environment.  Although some plants can immediately respond to a brush of a wind (Mimosa pudica), most like household plants move very slowly.  When given a substance like caffeine or steroids, it can have devastating effects.  In a human, caffeine simply goes to a neuron and basically occupies the Ca receptor and stimulates our muscles by keeping the flow of action potentials constant non-stop for a period of time.  A constant consumption of caffeine will result in a dead neuron, you will basically over work the neuron.  In a plant, the caffeine does not have a place to dock.  Instead, it messes up the different hormones or docks in crucial receptors that are needed for growth.  If the receptor is blocked, then the hormones cannot be expressed, causing a change in the growth pattern of the plant.  I mean, if caffeine is able to outcompete our natural signals, then it for sure can knock out a plants signal to grow in the right manner.
567715
Plants which reproduce without seeds appeared first in the history of the Earth.  Plants with seeds appeared much later.
508026
I would just talk about way plant and animal cells are constructed like cell walls and stuff. And talk about differences in how they make energy like animals burn sugar and plants first make sugar themselves. I'm sure that could be used to discuss nutrients issues.
653917
neurons come in many different sizes but you can assume the cell body of one neuron is 10 microns wide.  Some neurons are very short...less than a millimeter in length. Some neurons are very long...a meter or more! The axon of a motor neuron in the spinal cord that innervates a muscle in the foot can be about 1 meter (3 feet) in length.  http://faculty.washington.edu/chudler/what.html\n\nMost plant cells range in size between 10 and 50 micrometers.\nhttp://www.beyondbooks.com/lif71/4.asp
632303
no, they come from the environment.
385872
The answer could be (c), conifers.\nIn general, the plants that produce seeds without flowers are called Gymnosperms.  Conifers are gymnosperms.
79130
Stunning. You really don't have a single brain cell wandering around in your head, do you?
444959
Almost certainly a plant cell.
177992
uh...I don't think "tree" has any roots, but the stem (haha) "dendr" means tree
382778
Neurons have no charge. They are already charged. You need to study advance physics to find out why are they charged.
192241
Non-vascular plants do not have vascular systems to carry water, nutrients, ant the products of photosynthesis throughout the plant. Non-vascular plants include mosses, ferns, hornworts, and liverworts. The mosses, hornworts, and liverworts all transport water by osmosis so they cannot grow very large. This is why they must live so close to water. Ferns have a primitive forrunner of a vascular system, but it is not really a real vascular system because they do not have true roots, and also lack xylem, which is a type of cell that carries water and nutrients up the plant, and phloem, which are cells that can carry water, nutrients, and the products of photosythesis throughout the plant. If you have any more questions, I'll check back here for updates if this was helpfull at all.
659885
Because their brain is not advanced.
141369
Nitrogen is important to plant growth.
173328
Viruses are in a nether world. They are neither dead nor alive, and they certainly don't belong to a phylum or a class.
88729
You have to remember plants did not cause the atmosphere to become oxygenic in the primordial days, cyanobacteria did. I'm guessing there are probably trillions of trees in the world.
184498
hey the are not nephrons they are neurons . neurons are a part of the kidney
317355
We don't. Our other brain is working.