1. CONCEPT 28.4
ALVEOLATES HAVE SACS
BENEATH THE PLASMA
MEMBRANE
Namroo, Austin, Will

2. Table Of Contents
 Dinoflagellates
 Apicomplexans
 Ciliates

3. Intro
 Members of the clade Alevolata have alveoli,
small membrane-bound cavities, under the
plasma membrane.
 Their function is not known, but they may
help stabilize the cell surface or regulate
water and ion content.
 Alveolata includes flagellated protists
(dinoflagellates), parasites (apicomplexans),
and ciliates.

4. Alveoli
0.2 µm Flagellum Alveoli
Figure 28.9

5. Dinoflagellates
 Dinoflagellates are abundant components of
marine and freshwater phytoplankton.
 Dinoflagellates and other phytoplankton form
the foundation of most marine and many
freshwater food chains.
 Other species of dinoflagellates are
heterotrophic.
 Most dinoflagellates are unicellular, but some
are colonial.

6. Dinoflagellates Cont..
 Dinoflagellate blooms, characterized by
explosive population growth, can cause “red
tides” in coastal waters.
 Toxins produced by some red-tide organisms
have produced massive invertebrate and fish
kills.
 These toxins can be deadly to humans as
well.
 Some dinoflagellates form mutualistic
symbioses with coral polyps, the animals that
build coral reefs.

7. Ampicomplexans
 What are they?
 Sporozoites
 Apicoplasts
 Have sexual and asexual stages
 Plasmodium, Anopheles mosquitoes, and
malaria…

8. Insidemosquito Insidehuman
Merozoite
Sporozoites
(n) Liver
Livercell
Oocyst Apex
MEIOSIS Merozoite Red 0.5 µm
Zygote (n) blood
Red blood
(2n) cells cell
FERTILIZATION
Gametes Gametocytes
Key
(n)
Haploid (n)
Diploid (2n)
Figure 28.11

9. Ciliates
 Ciliates- protists who use cilia to move and feed.
 Completely cover the cell surface or may be clustered
in a few rows or tufts.
 A distinctive feature of ciliates is that there are
two types of nuclei.
 Large macronuclei – feeding, waste removal, water
balance
 Tiny micronuclei
 A cell may have more than one nucleus of each
type.

10. Feeding, Waste Removal,
Water Balance
Paramecium, like other freshwaterFEEDING, WASTE REMOVAL, AND WATER BALANCE
protists, constantly takes in water
by osmosis from the hypotonic Contractile Vacuole Paramecium feeds mainly on bacteria.
environment. Rows of cilia along a funnel-shaped oral
Bladderlike contractile vacuoles groove move food into the cell mouth,
accumulate where the food is engulfed into food
excess water from radial canals and vacuoles by phagocytosis.
periodically Oral groove
expel it through the plasma membrane.
Cell mouth
50 µm Thousands of cilia cover Food vacuoles combine with
the surface of Paramecium. lysosomes. As the food is digested,
the vacuoles follow a looping path
Micronucleus
through the cell.
Macronucleus
The undigested contents of food
vacuoles are released when the
vacuoles fuse with a specialized
region of the plasma membrane
Figure 28.12 that functions as an anal pore.

11. Reproduction and Conjugation
 Ciliates reproduce asexually by binary fission
 Conjugation causes genetic variation.
 A sexual process in which the two individuals
exchange haploid micronuclei.

12. CONJUGATION AND REPRODUCTION
Two cells of compatible 2 Meiosis of micronuclei
1
mating strains align side 2 produces four haploid 3 Three micronuclei in each cell
disintegrate. The remaining micr
by side and partially fuse. micronuclei in each cell.
nucleus in each cell divides by mi
MEIOSIS
4 The cells swap
one micronucleus.
Macronucleus
Haploid
Compatible Diploid micronucleus
mates micronucleus
Diploid
micronucleus
MICRONUCLEAR
FUSION
5 The cells
separate.
Two rounds of cytokinesis The original macro- Three rounds of
9 8 nucleus disintegrates. 7 mitosis without
7 6 Micronuclei fuse,
partition one macronucleus 8 forming a diploid
Four micronuclei cytokinesis Key
and one micronucleus micronucleus.
become macronuclei,
into each of four daughter cells. produce eight Conjugation
while the other four micronuclei. Reproduction
remain micronuclei.

13.  http://www.youtube.com/watch?v=rgkgD4Xc
qTk&feature=related
 http://www.youtube.com/watch?v=q6CefMU
Mtv4