Objective:
11.0 Classify animals according
to type of skeletal structure,
method of fertilization and
reproduction, body symmetry,
body coverings, and
locomotion.
Examples: skeletal structure —
vertebrates, invertebrates;
fertilization—
- external, internal;
reproduction -—
sexual, asexual;
body symmetry—
- bilateral,
radial, asymmetrical;
body coverings—
- feathers,
scales, fur;
locomotion—
- cilia, flagella,
pseudopodia
Protists
Chapter 20
What is a Protist?
Any
eukaryote that is not an animal,
plant, or fungus
Most are unicellular, but not all
Can be classified as animal-like,
plant-like, or fungus-like
Animal-like Protists
(Section12-2)
Heterotrophs
4
phyla, based on means of movement:
Zooflagellates
– swim through their aquatic
environments using flagella
Sarcodines – move via temporary
cytoplasmic projections called pseudopods
Ciliates – use _________ for feeding and
movement
Sporozoans – do not move on their own; are
parasites
Zooflagellates
Can
generally absorb food through
their cell membranes
Nutrients
from decaying organic matter
in water
From the bodies of other organisms in
which they live
Reproduction
can be asexual by
mitosis and cytokinesis, or sexual by
meiosis.
Sarcodines
Pseudopods
are used for feeding and
movement.
EX: amoebas
Reproduce asexually by mitosis and
cytokinesis
Source:
http://www.enchant
edlearning.com/subj
ects/protists/amoeba
.shtml
Ciliates
Cilia
are short hair-like projections.
The rapid beating of cilia propels ciliates
through water.
Most ciliates contain two different nuclei:
Macronucleus
– keeps multiple copies of the
genes
Micronucleus – contains a “reserve” copy of all
the cell’s genes
Obtain
food by using cilia to sweep food into
an indentation called the gullet
Reproduce asexually by _____ and _____, and
sexually by conjugation.
Paramecium
Source:
http://rookc.pbworks.com/w/page/46197520/Paramecium
Sporozoans
Live
as parasites on everything from
worms to humans
Reproduce by sporozoites
Protists and Disease
Malaria
– caused by the sporozoan
Plasmodium; spread by mosquito bites
African sleeping sickness – caused by
zooflagellate Trypanosoma; spread by
tsetse fly bites
Amebic dysentery – caused by parasitic
Entamoeba
Dysentery – flagellate Giardia
Plant-Like Protists: Unicellular Algae
(Section 20-3)
Contain
chlorophyll and carry out
photosynthesis
Commonly called “algae”
Seven major phyla, classified
according to a variety of cellular
characteristics (types of chlorophyll
or accessory pigments present):
First
4 phyla are unicellular
Last 3 contain many multicellular
organisms
1. Euglenophytes
Plant-like,
but have 2 flagella (like ???)
and no cell wall
Eyespot – cluster of reddish pigment that
helps organism find sunlight
Reproduce asexually by binary fission
Source:http://www.fcps.edu/islan
dcreekes/ecology/euglena.htm
2. Chrysophytes
“yellow
plants”
Includes yellow-green and goldenbrown algae
Chloroplasts contain bright yellow
pigment
3. Diatoms
Produce
thin, delicate cell walls rich
in silicon (Si) – the main component
of glass.
Look like etched petri dishes
Source:
http://deepbluehome.
blogspot.com/2011/0
1/psychedelicdiatoms.html
4. Dinoflagellates
About
half are photosynthetic;
others are heterotrophs
2 flagella, which wrap around the
the organism in grooves
Reproduce asexually by binary
fission
Can luminesce when agitated
Source:http://biology.un
m.edu/ccouncil/Biology_
203/Summaries/Protists
.htm
Source:
http://w
ww.ask
nature.
org/stra
tegy/d8
51e351
13506b
cf0219
e973da
169c29
Ecology of Unicellular Algae
Compose
most of the phytoplankton –
plant microorganisms at the bottom of
food chains
Algal blooms (“red tide”) –
Protists
can break down sewage in water
Excessive waste creates large
populations of euglenophytes, which
deplete nutrients in the water.
When they die, they can deplete oxygen
supplies needed by other organisms.
Plant-like Protists: Red, Brown,
and Green Algae (Section 20-4)
Mostly
multicellular
Reproductive cycles similar to plants
Many with cell walls and
photosynthetic pigments identical to
plants
Red Algae
Phylum
Rhodophyta (“red plants”)
Contain chlorophyll
and reddish
accessory pigments called
phycobilins, which can absorb blue
light, allowing them to harvest light
energy at great depths
Can actually be green, purple, or
redish-black in color
Play a role in coral reef formation
Lack flagella and centrioles
Brown Algae
Phylum
Phaeophyta (“dusky
plants”)
Contain chlorophyll
and c, as well
as a brown accessory pigment
(fucoxanthin)
Dark yellow-brown color
EX: giant kelp
Source:http://landsat.gsfc.nasa.gov/news/newsarchive/sci_0033.html
Green Algae
Phylum
Chlorophyta (“?????”)
Same photosynthetic pigment and
cell wall composition as plants
Contain chloroplast a and b
Life cycles of many include both a
diploid and a haploid generation
(“alternation of generations”)
Alternation of Generation
Source:
http://moodle.rockyvi
ew.ab.ca/mod/book/v
iew.php?id=58103&c
hapterid=21008
Fungus-like Protists
(Section 20-5)
Fungi
Both
Cell
walls
made of
chitin
Fungus-like
Protists
Heterotrophs;
Absorb
nutrients from
dead/decaying
matter
Have
centrioles
Molds
Slime
Molds:
Cellular
slime molds – individual cells remain
distinct (separated by cell membranes)
throughout life
Acellular slime molds – pass through a life
stage in which cells fuse to form large cells
with many nuclei
Water
Molds:
Thrive on dead or decaying matter in water OR are
plant parasites on land
EX: white fuzz on a dead fish in the water
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