Plants (tissues, organs, and organ systems) - B2

Question 1

Explain the function of these plant tissues:

Epidermal tissues)

Palisade mesophyll)

Spongy mesophyll)

Answer 1

Epidermal tissues - covers and protects the whole surface of plants (including leaves).

Palisade mesophyll – a layers of cells near the top of the leaf that contains lots of chloroplasts for photosynthesis.

Spongy mesophyll – cells in the middle of the leaf with air spaces between them and large surface area for efficient gas diffusion.

Question 2

Explain the function of these plant tissues:

Xylem)

Phloem)

Meristem tissue)

Answer 2

Xylem – Transports water (and mineral ions). Consists of bundles of dead cells that form woody tubes (strengthened by a substance called lignin) that transport water (and mineral ions) .

Phloem – Transports dissolved sugars, for immediate use or storage. Consists of tubes made from elogated living cells that have pores in their end walls to allow flow.

Meristem tissue – stem cells found at the growing tips of shoots and roots.

Question 3

What is the difference between transpiration and translocation?

Answer 3

Transpiration is the movement of water from roots, through the xylem all the way out of stomata.

Translocation is the the transport of dissoved sugars in plants, via the phloem.