1.8. TRANSLOCATION
This is the movement of food which has been manufactured in the leaf of plants through the phloem to various part of the plant the food substances are carried in then form of sucrose, along the phloem through sieve tube cells.
the xylem carries water and material salt from the roots to the leaf for the manufacture of food and after the food have been manufactured it is transported to various part of a plant through the sieve tube cells. This process is known as translocation.
The food substances are transported mainly to actively growing region of the plant which are called melismatic region and this include the shoot tip, root tip, and the cambium. The manufactured food is also transported to fruits seeds and storage organs.
The phloem cell is living cells while the xylem vessels is dead cells. The phloem cells are called sieve tubes cells and they have cross walls with sieve tube plates which allows liquid food to passthrough from one sieve tube cell to another.
1.8.1. EXPERIMENT ON TRANSLOCATION.
Aim:
Experiment to show that phloem vessels transport food down the leaf.
Requirements:
A potted plant, a razor blade.
Procedure:
Take a potted plant and cut a ring round a portion to it and another ring a little distance from that and peel off back of the stem. When this is done the phloem, cells are removed and the xylem cells are still intact. The plant is allowed to grow in the sun for a week or two.
Diagram:
Results:
The upper ring region of the stem will become swollen with accumulated food coming from the leaf. The leaf and branches of the potted plant remain fresh because they are still receiving water and mineral salt from the xylem vessel which are still intact
1.8.2. Importance of transpiration.
- Water from the soil move into the stem an then the leaf.
- Transpiration allows water and mineral salts to be taken in which cause the plant cells to be turgid
- Transportation allow mineral salt to be taken into the plant
- Transportation brings about a cooling effect on a plant on a hot day
- Because of these pulling effect energy from the sun is absorbed by green leaf of photosynthesis.
Next lesson: Classification of Living organisms
Njuh Mvo Fabrice
September 25, 2018
i can not find gce A and O level syllabus why i need them please
T- frank
October 4, 2018
sorry Mr Fabrice we don't have syllabus for now but with we are trying all our best to get some so we shall get them ASAP!!
Douanla Nde Yannick
October 5, 2018
very good initiative and more grace to your elbow. i wish to suggest that a means should be put in place for us teachers to upload our materials in the various fields (sylabus, scheme of works, sequence evaluations....).
T- frank
October 5, 2018
wow thank you Mr Yannick that is what came into our mind and we are working on that to.
Ntoko Stanley
November 8, 2018
please what about food science and nutrition?!? I haven't seen any advanced level paper on that!!
T- frank
November 10, 2018
just be patient Stanley we soon get that!
ANYUME J
January 21, 2020
Good initiative thanks
Des
June 2, 2022
I need specco 2022 o/l