Plant Like Protists
General Characteristics

Autotrophs

Seven major phyla classified by type of
photosynthetic pigment in chlorophyll
 Chlorophyll
a, b and c absorb different wavelengths of
light
 Accessory
pigments absorb light at other wavelengths
and pass energy to the photosynthetic process

Four unicellular phyla and three multicellular
Unicellular Plant Like Protists
Phylum Euglenophyta

Two flagella

No cell wall

Similar to zooflagellates except they have chloroplasts

Cluster of reddish pigment called an eyespot to help find
sunlight

Cell membrane called a pellicle (ribbon like ridges)

Ex. Euglena
Unicellular Plant Like Protists
Phylum Chrysophyta

Unicellular but can form colonies

Includes yellow-green and golden-brown algae

Chloroplasts contain bright yellow pigment

Cell walls can contain pectin and or cellulose
Unicellular Plant Like Protists
Phylum Bacillariophyta or Diatoms

Produce thin cell walls rich in silicon (Si) (just like
glass)
Unicellular Plant Like Protists
Phylum Pyrrophyta or Dinoflagellates

Half are photosynthetic and the other half are
heterotrophs

Usually two flagella

Many luminescent (give off light)
Ecology of Unicellular Algae

Make up most of the phytoplankton (bottom of
the food chain)

Half of the world’s photosynthesis

Algal bloom – nutrient run off in water, huge algae
growth spurt, huge algae death that robs water
oxygen, death of other organisms
 Red
fish
tide – produce dangerous toxins taken up by shell
Multicellular Plant Like Protists
Phylum Rhodophyta or Red Algae
 Contains chlorophyll a and reddish accessory pigments called
phycobilins

Good at absorbing blue light


Can live to a depth of 260 m
Can appear green, purple or reddish black depending on other
pigments
Most are multicellular
 Complex life cycles

Lack flagella and centrioles
 Help maintain the equilibrium of coral ecosystems

Multicellular Plant Like Protists
Phylum Phaeophyta or Brown Algae

Contains chlorophyll a and c and a brown accessory
pigment called fucoxanthin

Dark yellow brown colour

Largest and most complex of algae

Shallow water

Giant kelp can grow 60m in length
Phaeophyta continued…

Most common is Fucus (rockweed)

A holdfast attaches algae to the bottom

Flattened stem like structures called stripes

Leaf like structures called blades

Gas filled swellings called bladders to help the algae float
Multicellular Plant Like Protists
Phylum Chlorophyta or Green Algae
 Very similar to plants


Cellulose in cell walls

Chlorophyll a and b

Store food in the form of starch
Single celled types


Chlamydomonas – small, egg shaped with two flagella and
contractile vacuoles
Colonial types

Spirogyra – long threadlike colonies

Volvox – hollow spheres
Chlorophyta continued…

Multicellular types
 Ulva
(sea lettuce) – specialized cell types, only two cell
layers thick (why is this important to note), and a
holdfast

Reproduction
 Life
cycle include both a diploid (2N) and a haploid
(1N) generation
 Alternation
 Many
of generations
also switch between sexual and asexual forms of
reproduction
Ecology of Multicellular Algae

Major food source and habitat for life in the
ocean

Produces much of the world’s oxygen

Many species high in Vitamin C and iron

Treat ulcers, high blood pressure, and arthritis

Used to thicken food and other substances