Biology 1002 - Week 7 "Protists"

What are Diplomonads?

- A protist that has modified mitochondria, two equal-sized nuclei, and multiple flagella. - Are a group of flagellates, most of which are parasitic.

What is Trichomonas?

- Is a sexually transmitted infection and has a 90-95% cure rate if treated; pregnant women are at risk. - A vaginal inflammation caused by a protozoan parasite - Causes the sexually transmitted infection trichomoniasis.

What is Giardia?

- Is a tiny parasite (germ) that causes the diarrheal disease giardiasis. Caused by a microscopic parasite found worldwide. - A protozoa that causes giardiasis (diarrhea and stomach pain). - Intestinal parasite of mammals.

Diplomonads

- Lack mitochondria - Inhibit soil or water - May be parasitic - Unicellular - Giardia - Swim with flagella - Heterotrophic

Giardia

- Lacks mitochondria - Swims with flagella - Unicellular - Cysts forming - Trophozoites stage - Parasitic protozoan - Sometimes - animal stool can contain Giardia germs.

Kinetoplastids

- Swim with flagella - Heterotrophic - Inhabit soil or water - May be parasitic - Unicellular - Trypanosoma

Parabasalids

- Swim with flagella - Heterotrophic - Lack mitochondria - Parasites or mutualistic symbionts - Unicellular - Trichomonas

Euglenids

- Swim with one flagellum - Photosynthetic - Have one eyespot - All fresh water - Eugiena (common pond dweller.)

Conjugation?

A process in which two (2) organisms exchange genetic material.

What is Trypanosoma?

African sleeping sickness which is transmitted by teste flies and can develop inside of the new host.

What are the 'Three Modes of Nutrition' in Kingdom Protista?

Algae, in this kingdom, are autotrophs that trap solar energy and convert it to chemical energy through photosynthesis. Amoeba and Paramecium, predators, are heterotrophs that obtain energy and nutrients by capturing and ingesting prey. Many fungi like Protists are saprotroph's which absorbs nutrients from dead or decaying organic matter while a variety of protists are parasites.

Binary Fission

Asexual reproduction by a separation of the body into two new bodies.

Dr. Nemo went camping where there were streams and ponds and lots of animals. He ran out of his purified bottled water and was very thirsty and hesitated to drink or use the water from the stream. Why?

Because Giardia can be in the water which get into his system and infect him.

Why is it important to study protists?

Because they are producers, composers, direct food sources and can be used for medicine.

What is Foraminifera? (Short Forams)

Forams; have tests made of calcium carbonate; good indicators of underlying oil deposits. These are protists and single-celled.

What type of rock is White Cliff of Dover?

Formed from the chalky detritus of single-celled algae called coccolithophores. (Overlooks the English Channel).

What are the White Cliffs of Dover Made of?

Chalk

What are Excavates?

Free-living and symbiotic forms and many lack mitochondria or have a modified organelle, 2 or more flagella such as euglena and giardia. - inhibit soil or water - may be parasitic

Dr. Nemo had some water samples collected from the LSU lake. How can he detect the community of protists present in that water sample?

Dr. Nemo can detect the community of protists present in the sample by use of the Electron Microscope Magnification.

How did some Protist get plastids?

Endosymbiosis theory

What is the endosymbiotic theory?

Explains how eukaryotic cells may have evolved from prokaryotic cells.

Single cells of Diplomonads

Have two nuclei (2) and move about by means of multiple flagella.

Dr. Nemo went for a walk along the White Cliffs of Dover in the UK and scrapped a piece of the rock from the cliff, what do you think he will find in that sample?

He will find: - Coccolithophores - Calcium carbonate which is calcite - Dolomite which is the double carbonate of calcium and magnesium.

Merogony (schizogony)

In merogony, the nucleus and other organelles replicate repeatedly as the cytoplasm expands within the original cell membrane prior to cytokinesis into multiple identical uninucleate daughter cells.

Secondary Endosymbiosis

In which a non-photosynthetic protist engulfed a photosynthetic, chloroplast-containing protist.

What is an autotrophic bacterium?

It produces organic compounds from carbon dioxide. (Producer)

Do they have a special feeding mechanism?

Many Protists are predatory and have specialized structures designed to capture and aid in bringing nutrients inside their cells.

Protists Fact #3

Many protists are also capable of sexual reproduction. - Two individuals contribute genetic material to an offspring that is genetically different from either parent. - Nonreproductive processes that combine the genetic material of different individuals are also common among protists.

Protists Fact #1

Many protists are single-celled and invisible to us!

Protists Fact #2

Most protists reproduce asexually. - An individual divides by mitotic cell division. - Two individuals that are genetically identical to the parent cell.

Are Protists always Single-celled?

Most, but not all, Protists are single-celled. So, no.

Are Protists the same as fungi, plants, and animals?

No. The Protista Kingdom is paraphyletic - it contains the common ancestor but not all its descendants - and it includes those eukaryotic organisms that are not deemed to be animals, plants or fungi such as protozoa.

How do get Giardia?

One can get infected with Giardia if they swallow (food, water, germs of touch) and it gets into the small intestine where each cysts relates 2 trophozoites through excitation. Then they feed off of and absorb nutrients from the infected person.

Autotrophs

Organisms that are able to make their own food

Heterotrophs

Organisms that depend on other organisms for their food.

Protists Fact #4

Protists use diverse modes of nutrition: - They may ingest food, and they may absorb nutrients from their surroundings. - They may capture solar energy directly by photosynthesis. (In some protist photosynthesis takes place in chloroplasts.)

What theory can explain the very existence of Chloroplast and Mitochondria in eukaryotes?

The Endosymbiosis Theory

What is the reason that chloroplast and mitochondria exist in Eukaryotes?

The Endosymbiosis Theory states that the mitochondria and chloroplasts in eukaryotic cells were once aerobic bacteria (prokaryote) that were ingested by a large anaerobic bacterium (prokaryote). (The aerobic bacteria were initially free-living prokaryotes, before being ingested by anaerobic bacteria.)

How does cysts of Giardia form trophozoites?

The cysts of Giardia form trophozoites by the process of excitation where they separate in 2 in the small intestine.

What is the main chemical found in fossil nummulites found in construction material of Ancient Pyramids?

The main chemical found was foraminifera.

Are the White Cliffs of Dover made of Diatoms?

The sheer cliffs are composed of white chalk or calcite made by coccolithophores - tiny single-celled algae at the bottom of the marine food chain.

How did plastids orignate?

There origin is explained by endosymbiosis, the act of a unicellular heterotrophic protist engulfing a free-living photosynthetic cyanobacterium and retaining it, instead of digesting it in the food vaculoe.

What are the three most well documented ways by which a protist derives its nutrition?

Through ingestion, absorption, or through creating their own organic molecules.

If Giardia trophozoites and cysts are excreted in the stools that are released in the environment, then which stage/s can survive in the environment?

When Giardia is released through stool into the environment, it can no longer survive because it is not feeding on a cell.

Protist (some of them) can reproduce sexually without forming male and female reproductive cells. Is it true? But how?

Yes it is true. Some protists can reproduce without male and female reproductive cells by conjugation, or the exchange of genetic material.

Can a non-photosynthetic protist (like Paramecium) engulf a photosynthetic, chloroplast-containing protist (like Chlorella)?

Yes, a non-photosynthetic protist can engulf a photosynthetic chloroplast containing protists.

Do Protists produce like animals and plants?

Yes, actually protists produce both ways. (Animal-like amoebas and plant-like Euglena reproduce asexually.) (While others reproduce sexually, which requires 2 parents.)

Are Protists locomotory?

Yes, they have various means of locomotion.

Do Protists have a nuclei?

Yes. For the cells of all Protists have a nucleus and other complex organelles.

Do Protists have organelles like chloroplast?

Yes. Photosynthetic Protists cells have chloroplasts, which are the organelles that are able to capture the energy from the sunlight and turn it into sugars.

Endosymbosis

a mutually beneficial relationship in which one organism lives within another.

Saprotrophs

an organism that feeds on or derives nourishment from decaying organic matter.

Plastids

any of a class of small organelles, such as chloroplasts, in the cytoplasm of plant cells, containing pigment or food.

Chloroplast

are a descendant of ancient photosynthetic bacteria that took up residence inside larger cells in a process called endosymbiosis.

How do Protists reproduce asexually?

by binary fission or multiple division by either merogony (schizogony) or plasmotomy.

Limestone

is a sedimentary rock composed principally of calcium carbonate (calcite) or the double carbonate of calcium and magnesium (dolomite).