Biology HW
1.What is transportation?
2.What is the difference between xylem and phloem
3.Write the function for following.
a.Xylem parenchyma
b.Xylem sclerenchyma
c.sieve tube
d.companian cell
Answers
Answer:
1) the action of transporting someone or something or the process of being transported.
2)Xylem is the complex tissue of plants, responsible for transporting water and other nutrients to the plants. Phloem is living tissue, responsible for transporting food and other organic materials. ... Phloem transports food materials that are prepared by the green parts of the plants to other parts of the plant.
3) (a) Xylem parenchyma is present in the xylem of all vascular plants. (i) The xylem parenchyma cells, as usual, store food materials in the form of reserve foods like starch or fat. (ii) They also store other substances like tannins. (iii) These cells help in the radial conduction of water, i. e., in the radial directions.
(b) Following are the functions of xylem: (i) To carry water and mineral salts upwards from the root to different parts of shoots. (ii) To provide mechanical support to the plant as the walls of tracheids, vessels, and fibres of xylem are lignified.
(c) The main functions of sieve tube members include maintaining cells and transporting necessary molecules with the help of companion cells. The sieve tube members are living cells (which do not contain a nucleus) that are responsible for transporting carbohydrates throughout the plant.
(d) Companion cells move sugar and amino acids into and out of the sieve elements. In 'source' tissue such as leaf companion cells use transmembrane proteins to take up sugar and amino acids by active transport. ... Loading sets up a water potential gradient that facilitates movement of sugar.
Explanation: