It is involved in long distance transport of photosynthate. It has no special thickening in its cell wall. A microscopic cross section of a plant shows a very well developed endodermis and cortex. At the dead center of the stele there are a mass of very thick walled cells of varying diameters. No protoplasts are seen in this area.
Flowers are actually modified a. leaves b.
There are three tissue systems of a plant. If a man with type A blood marries a woman with type B blood, what is the probability that they will have a child with type B blood. Both the man's father and the woman's mother have type O blood. It joins the leaf to the node of the stem. Companion cells a. are connected to vessels by plasmodesmata b. are an integral part of phloem c. aid in loading sugar into sieve-tube members d. help to regulate pressures in vessel elements e.