Chapter 24-25 Plants Internal and External Structure

What are 2 types of phloem cells

Sieve tubes and companion cells
What is the function of phloem?

Transports food around the plant.
What are sieve tubes?

Sieve tubes are the only living plant cell that have no nucleus and are kept going by companion cells.
What is the structure of sieve tubes?
- Living, long, cylindrical cells, placed end to end.
- No nucleus. Thin cellulose walls.
- Cross walls pitted and known as sieve plates.
What are sieve plates?

Pitted cross walls of sieve tube.
What is the function of sieve tubes?

Transport food and hormones (auxins) to all plant cells from the leaves.
Why is there no lignin present in sieve tubes/ any phloem type?

As they’re not transporting water.
Where and how is food made?

Food is made in leaves by photosynthesis then transported elsewhere - from source to sink ~> leaves to roots.
What does phloem and our blood vessels have in common?

Both transport hormones.
What are companion cells?

Type of phloem that keeps sieve tubes going.
Why do companion cells keep sieve tubes going?

Sieve tubes have no nucleus and companion cells do.
What is the structure of companion cells?
- Living, thin-walled, long cells.
- Nucleus present.
- Lie beside sieve tubes in vascular bundles.
- Controls activities of the sieve tubes.
What do companion cells do?

Control activities of sieve tubes.
What do sieve plates allow?

Sieve plate allows movement of food.

Author

jacquelineglynn

356738

Card Set

Chapter 24-25 Plants Internal and External Structure

Description

Questions

Updated

2021-05-03T18:33:24Z