Transcript Seaweed Notes II

Exit Questions.
1. How do seaweed reproduce Sexually?
And Asexually?
2. List three uses of seaweeds.
3. List three characteristics of sea grasses.
4. List three characteristics of salt-marsh
plants.
5. List three characteristics of mangroves
Seaweed Notes
Part II
Reproduction
• Seaweeds can have very complex
reproductive strategies.
• Both asexual reproduction (cell division)
and sexual reproduction (using gametes)
are very common.
Reproduction
• Some seaweeds produce spores that are
protected by cell walls (for adverse
conditions).
• Some spores have flagella for movement
(zoospores).
Alternation of Generations
• Some sexual reproduction may involve
both sexual and asexual reproduction.
•One generation
will reproduce
sexually while the
next reproduces
asexually.
•When this
happens there are
often two different
types of thallus,
one for each
phase.
Uses of Seaweeds
• Food: Many cultures eat seaweeds in a
variety of ways.
– Most commonly we observe them in sushi.
• Mariculture: the farming of seaweed.
Uses of Seaweeds
• Seaweeds produce chemicals that help form
gels and are often added to dairy products to
keep them smooth (yogurt, ice cream, cheese,
etc).
• They are also used to keep frostings and pies
from drying out.
Uses of Seaweeds
• Shampoos, plastics, and pesticides.
• Cosmetics and laxatives.
• Hospitals can use seaweeds in some
wound dressings.
Marine Flowering Plants
• There are many terrestrial flowering
plants, but only a few marine flowering
plants.
• These do have true roots, stems and
leaves.
–They need
specialized tissues
to transport water,
nutrients, and food.
Seagrasses
• The only true marine flowering plants.
• Most are found in shallow, well protected
water in many temperate and tropical
regions.
Seagrasses
• Most have flat, ribbon-like leaves.
• There are many organisms that live
among the seagrasses including
herbivores (seaturtles, manatees, and
some fish).
Salt-marsh Plants
• Not true marine flowering plants.
• They are plants that are tolerant of salty
conditions.
•They cannot be
totally submerged
by salt water.
Salt-Marsh Plants
• They can survive in area that are partially
submerged at high tide.
• Their leaves remain exposed to air and
are able to excrete excess salt.
Mangroves
• Trees and shrubs adapted to live along
tropical and subtropical shores.
• Land plants that can tolerate salt and are
protected from waves.
Mangroves
• Leaves are usually
thick to help
reduce water loss.
• Some seeds will
germinate while
attached to the
parent to give
them a better
chance at survival
when they fall off.