Transcript Rhizopoda

Rhizopoda
By: Seth Rudd
Radiolarians
1.
2.
3.
Mostly marine forms with
glassy shells that differ in
shape from each species
Have skeletons most
commonly made of silica.
When they die their
skeletons accumulate at sea
bottom and form ooze
Have a segregated soft
anatomy into the central
capsule containing the
endoplasm, and the
surrounding ectoplasm
Foraminiferans
1.
2.
3.
Almost all marine, most
species live in the sand or
attach themselves to rocks
and algae, but some are also
abundant in plankton
Single celled protists with
shells also called tests.
Shells are commonly divided
into chambers which are
added during growth
Foraminiferan fossils, caused
by their calcium carbonate
shells, are excellent markers
for correlating the ages of
sedimentary rocks in different
parts of the world
Heliozoans
1.
2.
3.
Mainly freshwater protists
with stiff axopodia used for
feeding
Roughly spherical
amoeboids with many stiff,
microtubule supported
projections called axopods
Similar to radiolarians but
they are distinguished from
them by lacking central
capsules and other complex
skeletal elements
Amoeba
1.
2.
3.
All unicellular and use
pseudopodia to move and
feed. Cytoskeleton consists
of microtubules and
microfilaments that help in
amoeboid movement
Has simple contractile
vacuole to maintain osmotic
equilibrium
Reproduce asexually by
various mechanisms of cell
division, mitosis, and
cytokenesis. Spindle fibers
form but all stages of mitosis
aren’t apparent
Three Facts
1. Some Rhizopodians are important parasites.
Entamoeba histolytica causes amebic
dysentary and other Entamoeba is a common
symbiont in the human mouth where it feeds
on bacteria and human macrophages
2. Some Rhizopodians are among the largest
protists known. For example, Pelomyxa
palustrus, easily reaches 5mm in length
3. Amoebas obtain their food through
phagocytosis