Structure and Function of Phloem

Question 1

What is the function of the phloem

Answer 1

o transport food (mainly sugars like sucrose) from where it’s made (source) to where it’s needed or stored (sink).

Question 2

hat does “Source to Sink” mean in phloem transport

Answer 2

Source = where sugar is made (e.g. leaves during photosynthesis)

Sink = where sugar is used or stored (e.g. roots, fruits, growing parts)

Question 3

What is the structure of phloem tissue?

Answer 3

Made of sieve tube elements and companion cells

Sieve tubes have pores (sieve plates) and no nucleus

Companion cells have nuclei and support the sieve tubes

Question 4

How do sieve tube elements help in transport?

Answer 4

Long and joined end-to-end to form tubes

Sieve plates have holes to allow easy flow of food substances

Lack of nucleus makes more room for transport

Question 5

What is the role of companion cells?

Answer 5

They control and provide energy for the sieve tubes

Help load and unload sugars into the phloem using active transport

Question 6

How is the phloem transport process called?

Answer 6

Translocation – the movement of sugars from source to sink.