Module 3: Transport in plants

Question 1

Is phloem a living/dead tissue?

What is the main function of the phloem?

Answer 1

its a living tissue

to transport food in the form of organic solutes from the leaves where they’re made in photosynthesis to the rest of the plant

Question 2

What does the phloem supply cells with and why?
2

Answer 2

the sugars and amino acids they need for cellular respiration and the synthesis of all other useful molecules

Question 3

What is the direction of flow in the phloem?
(What name is given to this flow)

Answer 3

goes up and down the plant

Bi-directional

Question 4

What is the name given to the main transporting vessels in the phloem?

Answer 4

the sieve tube elements

Question 5

Both the xylem and phloem are made of sieve tubes that are many cells joined end to end to form long hollow structures , however there is a difference in the phloem , what is this?

Answer 5

the walls dont contain lignin , so in the areas between cells the walls become perforated and form sieve plates which let the phloem contents flow through

Question 6

What happens as a result of these sieve plates (pores) appearing?
2 points

Answer 6

the tonoplast , nucleus and some organelles break down

this means the phloem fills with phloem sap and the mature phloem cells have no nucleus

Question 7

What component is closely linked with sieve tube elements?

Answer 7

companion cells

Question 8

How are companion cells linked with sieve tube elements?

Answer 8

by many plasmodesmata