Kingdom Protista

Kingdom Protista General Characteristics

Yes or No. 1. All protists are microscopic. 2. Only a few of them are free living.

No. Most of … No. Most of ….

3. It is only composed of single-celled organisms

No. some are multi…

4. Most protists are aquatic ( marine and fresh ).

Yes

5. Some can survive on rocks, damp places, soil and leaf litter 6. There are parasitic protists in plants and animals.

Yes

Yes

7. All protists are heterotrophic.

No. some are photosynthetic

8. Some of them can switch their mode of nutrition Yes. be photosynthetic at certain times and be heterotrophic at other time 9. They can reproduce asexually and sexually

Yes.

10. All protists are non-motile. No. Some can move using flagella or cilia 11. Protists exhibit symbiotic relationship. 12. They are eukaryotic with cell organelles.

Yes. Mutualistic/ Parasitic Yes.

What are the major groups of protists ? 1. Animal- like protist

Protozoa / protozoons

2. Plant-like protist

Alga / algae

3. Fungi-like protist

Slime molds and water molds

1. Protozoa ( animal –like protists ) a. Phylum Rhizopoda

- are found in soil, fresh and marine - unicellular - reproduce asexually only

- pseudopods ( false feet) are used for locomotion and ingestion of food Entamoeba histolytica causes amebic dysentery in human Examples

Acanthamoeba causes opportunistic infections such as eye infections in contact lens users.

Foraminiferan

- almost all are marine organisms

Ex. Rotaliella

- secrete chalky, many- chambered shells with pores - cytoplasmic projections are used to entangle prey -when they die, they form a grey mud that is gradually transformed into chalk layer Ex. White Cliffs of Dover, London

b. Phylum Zoomastigina

( flagellates )

- have flagella - found in fresh, marine, and body fluids of animals - ingesting or absorbing - asexual - free –living or symbionts

Ex. Trypanosoma gambiense – African sleeping sickness Trichonympha – present in the intestine of termites ( digest cellullose using their cellulase enzyme )

c. Phylum Ciliophora

( Ciliates )

Ex. Paramecium - cilia

- most feed on bacteria

- fresh water

-they differ from other protists in having two types of nuclei a. macronuclei control cell metabolism and growth b. micronuclei take part in conjugation

Ex. Stentor - non motile - found in shallow part of the coastal seas

d. Phylum Apicomplexa

( Sporozoa )

- sporozoa are a large group of parasitic parasitic protozoa - no organelle for locomotion

Ex. Plasmodium - causes Malaria - the vector of this disease is the female Anopheles mosquito Assign.

Discuss how Malaria develops in mosquito and human hosts. ½ crosswise paper

3. Fungus-like protist

Why fungus-like protists? - superficially resemble fungi in that they are nonphotosynthetic and their body form is often threadlike hypae

- have centrioles and flagellated cells, which fungi lack - cell wall is composed of cellulose; fungal cell wall is chitin

a. Phylum Myxomycota ( Plasmodial Slime Molds )

Ex. Plasmodium of Physarum plasmodium – is a vegetative stage of the slime molds - contains many diploid nuclei ( multinucleate ) - logs, and leaf litter - feed on bacteria, yeast, spores, decaying organic matter, and ameba - reproduce asexually and sexually ( gametes are involved )

When conditions are not favorable and food is insufficient they produce SPORANGIA, reproductive structures

In sporangia, haploid nuclei are produced, which later surrounded by a cell wall to form SPORES which are resistant to adverse envi. when conditions are favorable, spores in the sporangia break out and release their flagellated cells

the flagellated cells ( act as gametes) fuse together to form diploid cells

diploid cells divide by mitosis ( cell division ) hundreds of diploid cells form another plasmodium

b. Phylum Oomycota

( water molds )

- they form a MYCELIUM ( a mass of threadlike structure and a vegetative body) - a mycelium is composed of threadlike HYPHAE ( cells ) - cell wall is composed of cellulose and/or chitin -reproduce asexually and sexually; products of the fusion of male and female gametes are called OOSPORE

In 1840s, water molds affected almost all potato plantations in Ireland.

Late blight potato disease ------------ starvation ------------- death ( .5 – 1 mil. )

A mass migration out of Ireland to USA