Please answer as many questions as you can on Biology?

Question

Im studying for a test and was wondering these answers...thx....
DEALING WITH ROOTS.

1. explain how root tip moves through soil

2.what is a stele

3.Why are old roots and stems identical in terms of tissues and functions.

4.Why are there no root hairs on old sections of the root

5. Ehy do biologists associate downward material movement with xylem and upward with phloem.

6.Explain how vascular cambium produces more xylem each year and how it contributes to secondary development

Answer 1

Instead of answering your questions one by one, I'm going to advise you to go to the link below. It will answer every one of your questions in a way that you can understand them, together with labeled pictures that I can't show you here.

With one exception (5) which you or whoever made up these questions seem to have gotten backwards.
The xylem transports sap from the root up the plant. Xylem sap consists mainly water and inorganic minerals can also contain some smaller amounts of organic elements as well. The sap in xylem is always upward.
Unlike xylem (which is composed primarily of dead cells), the phloem is composed of still-living cells that transport sap. The sap is a water-based solution, but rich in sugars made by the photosynthetic areas. These sugars are transported to non-photosynthetic parts of the plant, such as the roots, or into storage structures, such as tubers or bulbs. Movement of sap in phloem is usually downward but can be bidirectional as well taking the sugars from photosynthesis were it is needed most. Good Luck

Answer 2

1.root moves in side soil due to positive geotripism
2.steel is the conduting zone in plants.it has xylem to conduct water and phloem to conduct food materials

3.mostly true cuz the secondary xylem and secondary phloem in both root and stem are similar
4.Root hairs can be seen only on epidermis.older roots lack epidermis due to secondary growth
5.No that is wrong water absorbed by roots is conducted to various plant parts in up ward movement and food materials prepared by leaves is conducted by phloem in all directions

6.vascular cambium produce more secondary xylem which give more strength to plant and that is not useful for conduction of water.More secondary xylem or wood means more strength

Answer 3

1) - the zone of elongation cause cells to grow in length. the weight of the overhead plant causes it to grow down