Movement in the Phloem

Question 1

Thus translocation within phloem tissue can be defined as the

Answer 1

transport of assimilates from source to sink and requires the input of metabolic energy (ATP)

Question 2

The liquid that is being transported (found within ………….) is

Answer 2

phloem sieve tubes

phloems sap

Question 3

This phloem sap consists of

Answer 3

not only of sugars (mainly sucrose) but also of water and other dissolved substances such as amino acids, hormones and minerals

Question 4

The source of the assimilates could be

Answer 4

Green leaves and green stem (photosynthesis produces glucose which is transported as sucrose, as sucrose has less of an osmotic effect than glucose)

Storage organs eg. tubers and tap roots (unloading their stored substances at the beginning of a growth period)

Food stores in seeds (which are germinating)

Question 5

The sinks (where the assimilates are required) could be

Answer 5

Meristems (apical or lateral) that are actively dividing
Roots that are growing and / or actively absorbing mineral ions
Any part of the plant where the assimilates are being stored (eg. developing seeds, fruits or storage organs)

Question 6

The loading and unloading of the sucrose

happens form what to what

Answer 6

from the source to the phloem, and from the phloem to the sink is an active process

Question 7

The loading and unloading of the sucrose from the source to the phloem, and from the phloem to the sink is an active process
It can be slowed down

Can be stopped or slowed by

Answer 7

high temperatures or by respiratory inhibitors

Question 8

Assimilates can in what directions

Answer 8

move upwards or downwards in the phloem sieve tubes as they move from source to sink.