Transport in the Phloem

The phloem transports organic substances produced during _______________.

There are _________ main types of phloem cells.

The main types of phloem cells are listed below. Check the boxes that apply.

• sieve tube elements

• tracheids

• companion cells

• phloem parenchyma

• phloem fibres

Another name for organic substances transported by the phloem is _______________.

Sieve tube elements are very narrow and between ______ micrometers in diameter.

The organelles not present in the sieve tube elements - check all that apply.

• mitochondria

• nucleus

• Golgi body

• ribosomes

• endoplasmic reticulum

The cytoplasm of the companion cell is connected to that of the sieve tube element via ___________________.

The end wall of a sieve tube element is called a _______________.

Each plasmodesmata is at least ______________ nm wide.

In damaged sieve tubes, the sieve pores are blocked by a carbohydrate called __________________.