Identify FOUR ‘adaptations’ of seagrasses to subtidal environments. Briefly explain the significance of each of these ‘adaptations’.

Question 1

Provide a definition of the seagrasses:

Answer 1

• Angiosperms- flowering plants (monocots)
• Adapted to a saline environment
• Ability to grow completely submerged
• Reproduce underwater
• Strong rhizomes
• Clonal growth

Question 2

Explain the importance of thin cuticles with no stomata:

Answer 2

• Thin cuticles, no stomata
o Water evaporates out of the leaves through the stomata, so by these closing up seagrasses are able to prevent water losses
o Waxy surface instead that is thin enough to allow for diffusion of gases

Question 3

Explain the importance of leaf sheaths to protect against salt:

Answer 3

• Leaf sheaths protect from salt
o Salt damages cell metabolism and physiological processes
o Protects young growing part of the leaves from salt, before the cells have had the ability to build up protection
o Tightly packs in and stops salt getting into the young cells

Question 4

Explain the importance of fibers for strength and flexibility:

Answer 4

o Marine plants need to deal with a lot of wave action

o A lot of cellulose fibres able to withstand the wave energy quite well

Question 5

Explain the importance of arenchyma and spaces- tissues to conduct air through the plant (especially the roots):

Answer 5

• Aerenchyma and spaces- tissues to conduct air through plant (especially roots)
o Within a few centimetres of sediment there is basically no oxygen
o Air spaces allow plants to get air from the top of the seagrasses down to the roots