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CHAPTER 4 PROTISTA

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CHAPTER 4 PROTISTA Powered By Docstoc
					                             CHAPTER 4: KINGDOM PROTISTA

OVERVIEW:

 -________________: organisms that make their own food through photosynthetic
processes.

-_________________: more animal-like, motile organisms that ingest large food particles
and digest them intracellularly.

-___________________: type of reproduction that occurs without genetic recombination
and results in the production of offspring that are genetically identical to the parent; may
occur by simple fission of a single cell, budding or fragmentation.

-________________: type of reproduction in which offspring with unique genetic
combinations are created by the union of sets of genetic material, usually, but not
necessarily, from two separate parents.

-_________________: a member of the paraphyletic kingdom Protista, generally
considered to include the protozoan groups and eukaryotic algae.

-Paraphyly: the condition that a taxon or other group of organisms contains the most recent
common ancestor of all members of the group but excludes some descendants of the
ancestor.

-Monophyletic: pertaining to a taxon derived from a single ancestral species that gave rise to
no species in any other taxa.

-Polyphyletic: pertaining to a taxon whose members were derived from two or more
ancestral forms not common to all members.

-Taxon: any taxonomic group or entity.

-Taxonomy: study of the principles of scientific classification; systematic ordering and
naming of organims.

-Clade: a taxon or other group consisting of an ancestral species and all of its descendants,
forming a distinct branch on a polygenetic tree.

-                      protists: an informal way to refer to the unicellular forms of protists.

-                      protists: an informal way to refer to the multicellular algae and slime
molds.

-                       : the membrane at the boundary of a cell that acts as a selective
barrier regulating the cell's chemical composition.

-                     : protective, rigid outer layer of the cells of plants, fungi, bacteria and
many protists; may consist of cellulose, calcium carbonate, silica or other materials.

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-Starch: storage polysaccharide consisting of long polymers of glucose molecules; found in
plants and some protists.

-Lipids: family of compounds including fats, phospolipids, and steroids, that are insoluble in
water; lipids combine with proteins and carbohydrates to form principal structural
components of cells.

FINALLY, PROTISTS...

-Over 60,000 different known species.

-ALL PROTISTS CAN REPRODUCE ASEXUALLY BY ________________ (generally by
simple fission), yet many have the ability to reproduce sexually through a combination of
meiosis and nuclear exchange.

-We will look at four subdomains of protists:

     1.) Euglenozoa: _________________and ____________________
     2.) Alveolata: ___________________, ______________________, and
____________________
     3.) Stramenopila: ________________, Golden algae, Brown algae, and Water molds
     4.) Rhodophyta: Red algae (and Green algae)

Exercise 4-1: Euglenozoa (__________________ and ___________________)

-Euglenoids and kinetoplastids have _____________ (pl. = ___________): long cellular
appendages specialized for locomotion.

-All Euglenoids are unicellular, motile flagellates that reproduce asexually by binar y fission.
Many species are heterotrophic, but some are also photosynthetic. All have flexible cell
membranes.

-The flagellum of euglenoids propels like a _____________________.

-Euglenoids store glucose in the form of lipids rather than as startch; making them more
animal-like in their method of food storage.

-Two types of flagella: Whiplash flagellum - pushes the organism through the medium.
                     Tinsel flagellum - pulls the organism through its environment.

-Euglena: a typical englenozoan.

-____________________ are unicellular, parasitic flagellates characterized by a single,
large mitochondrion containing kinetoplast - a unique organelle that houses extra-nuclear
DNA.

-Example = Trypanosoma brucei (a human pathogen, which means it's capable of
producing disease) causes African sleeping sickness, spread by the bite of a tsetse fly.

QUESTION: How are kinetoplastids similar to euglenoids? How are they different?
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Exercise 4-2: Alveolata (____________________, ______________________, and
___________________)

-All members of this group of unicellular protists have small cavities under their surfaces
called alveoli (function unknown).

--Dinoflagellates: mostly marine, unicellular autotrophs whose flagella arise from two
perpendicular grooves formed along internal cellulose plates.

        -Unlike euglenoids, dinoflagellates push themselves through the water with their
flagella.

        -Perpendicular grooves: characteristic pattern of grooves in dinoflagellates, in which
their two flagella lay.

      -Cellulose plates: structural element of dinoflagellates found beneath the outer
plasma membrane providing support and shape to their cells.

-Dinoflagellates are among the most important primary photosynthetic producers of organic
matter in the oceans.

       -Chlorophyll c: their primary photosynthetic pigment.
       -Reserves of glucose may be stored as starch or lipids.

       -___________________: when nutrients are abundant, certain marine dinoflagellates
experience large population "blooms" in such enormous numbers that they color the ocean
waters a deep reddish color. The toxic conditions produced by these red tides poison
massive numbers of fish and make shellfish unfit for human consumption.

QUESTIONS: 1.) What ecological importance do dinoflagellates have?

       2.) Describe how the motion of dinoflagellates differs from that of euglenoids.
--Sporozoans: unicellular parasites characterized by an apical complex of organelles that
they use to penetrate the host cell. Heterotrophic.

       -__________________: a blood parasite carried by a secondary host, the female
Anopheles mosquito, which transmits the parasite to humans. (The mosquito serves as a
vector for the parasite). Only infects the red blood cells.

--Ciliates: unicellular hetertrophs that possess cilia (similar to rowing) for locomotion and
feeding, have two types of nuclei: micronuclei and macronuclei.

       Paramecium: a typical ciliate.

-Micronucleus: typical eukaryotic nucleus containing the entire genome; essential for genetic
recombination.

-Macronucleus: organelle containing many copies of a few genes; primarily controls
metabolic processes of the cell.
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-________________________: process in which genetic material from one cell is
transferred to another cell, or genetic material from two cells in simultaneously transferred.

       -During conjugation, 2 paramecium align longitudinally and attach. The micronuclei
in each cell undergo meiosis to create 4 haploid micronuclei per parent micronucleus.

-______________________: type of cell division by which many unicellular protists
reproduce asexually; the micronucleus divides by mitosis, while the macronucleus and
remainder of the original cell simply split in half to produce two genetically identical daughter
cells.

QUESTION: Why is conjugation considered a form of sexual reproduction?

Exercise 4-3: _________________, golden algae, brown algae, and water molds)

-Diatoms: freshwater and marine unicellular autotrophs that have two-part cell walls made of
silica, a natural glass.

        -Diatomaceous earth: type of soil formed by the accumulation of siliceous diatom cell
walls over hundreds of millions of years. Is mined and used commercially in fine abrasives,
silver polishes, toothpaste, reflective roadway paint additive.

Exercise 4-6: Amoebas and slime molds

-Amoebas: unicellular heterotrophs that lack cell walls.

       -______________: flexible plasma membranes that are cytoplasmic extensions used
for feeding and locomotion.
       -Some amoebas are parasitic such as Entamoeba histolytica, the causative agent of
amoebic dysentery.

-Slime molds: unicellular organism that can be very large; one big cell but can have
numerous nuclei.

       -Cytoplasmic streaming: phenomenon in which cytoplasm of a cell flows from one
region of the cell body to another, often as a means of distributing food, gases, or other
substances.




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