Seagreass and Mangroves

Question 1

What are seagrasses

Answer 1

Monocotyledonous plants with roots capable of nutrient absorption and vascular tide capable of nutrient translocation. They are mostly sub tidal and more light dependent than seaweeds and therefore only found up to max 90m. Generally grow in sand and mud

Question 2

What are the 2 uk species of Seagrass

Answer 2

Zostera noltii which is a smooth seaweed with upper limits set by desecration uv tolerance and wave action

Zostera marina ridged seaweed which only found down to 10m

Question 3

How do seagrasses reproduce

Answer 3

Can be both asexual or sexual most are dioecious (different sexes) to reduce self fertilisation and give rise to biodiversity

Relatively little energy is put into sexual reproduction. Flowers aren’t extravagant as they don’t need to attract pollinators as water carries the pollen. Pollen have a range of forms adapted to conditions

Question 4

Adaptation of Seagrass seed dispersal

Answer 4

Seeds vary is structure and dispersal properties
Desen seeds = little dispersal distance
Buoyant seeds = long dispersal distance
The germination of the seed occurs quickly after settlement
A lack of seed bank affects the recovery of a population from a disturbance and it slows down germination

Question 5

What are mangroves

Answer 5

Grow on unconsolidated sediment and briefer a saline water body while water level fluctuated tidally
Salt tolerant plants with low species diversity

Question 6

Mangrove reproduction

Answer 6

Viviparous plants (parental investment) whose seeds germinate still attached to the parent this is though to protect the young (propagules) from high salinity environment
Propagules may stay attached for up to a year

Question 7

Mangrove dispersal

Answer 7

When they detach they are buoyant and can travel great distances if area isn’t suitable they can remain buoyant to find a new place for up to a year

Question 8

Seagrass adaptation

Answer 8

Seagrasses have high light requirements and therefore Lacunae (air pockets) bring co2 produced via respiration in the roots to the leave for photosynthesis
Seagrass is considered euryhaline (B-road tolerance to saline) however suffer stress at too high or low concentration of saline
Mechanisms to withstand salinity include exclusion of salt from their tissues as intracellular enzymes are not salt tolerant so salt salt can be excluded to the vacuole from the cytoplasm

Question 9

Mangrove adaptation

Answer 9

Also exclude salt from the cells to the vacuole from the cytoplasm
Eliminate excess salt via secretion
Shedding unwanted ions in plant parts
Avoid water-loss via a waxy cuticle and stomata