Biology- plants tissues?

Question

1. are guard cells protective/dermal tissue?

2. are phloem and xylem RAYS vascular or ground tissue?

(what are their functions)

3. What type of tissue is spring and summer wood? What are their functions?

4. Is pith ground tissue? And what is its function along with the pith ray?

Answer 1

1.  Guard cells form an opening through the epidermis allowing for gases to enter and leave the leaf.  The guard cells can be considered to be both protective and dermal cells.

2.  Rays are composed of parenchyma cells but do function in movement of fluids laterally to the outside of the tree.

3.  Spring wood and summer wood are composed of xylem cells.  The difference is due to amount of water and nutrients available for formation of new cells by the vascular cambium.

4.  Pith is formed primarily by parenchyma, a ground tissue.  Food reserves can be found in the parenchyma in some plants.

5.  The stele is formed by the endodermis, pericycle, xylem and phloem.  Cut a carrot length-wise (longitudinally) and you'll see the stele in the center of the root with the cortex to the outside.

Answer 2

1. Guard Cells are in the dermal tissue yes. They open and close the stomata.

2. They are both Vasuclar (rays as well)

Xylem  =  conducts water and nutrients from the roots to other parts of the plant.

Phloem = conducts food from the leaves to the stem and roots.

3. Vascular (secondary xylem tissue makes the wood). I think it is mainly to conduct water.

4. Yes the pith is a part of the ground tissue. The function of pith is to store nutrition, at the same time, its parechymatous quality enables it to take responsbility of transporting nutrients to outer tissues in the plant.