Chapter 19: Protists

protozoan, alga, pseudopodia, asexual reprodution, flagellate,

ciliate, sporozoan, spore

What is a Protist?

Protista is the most diverse kingdom.

Unicellular or Multicellular

Microscopic or very large

Heterotroph or Autotroph

What is a Protist?

Some protists are animal-like and are called protozoa.

Plantlike protist are called algae.

Some protist can also be fungi-like.

Protozoans

All protozoans are unicellular heterotrophs that feed on other organisms or dead organic matter.

They usually reproduce asexually, but some also reproduce sexually.

They are grouped according to the way they move.

Protozoans

Some protozoans use cilia or flagella to move.

Some move and feed by sending out cytoplasm-containing extensions of their plasma membrane called psudopodia.

Others are grouped together because they are parasites.

Protozoans

There are four main groups of protozoan1. Ameobas

2. Flagellates

3. Ciliates

4. Sporozoans

Amoebas: Shapeless Protists

Phylum Rhizopoda amoebas that move by

extension of their cell body called pseudopod that form a Pseudopodia. Pseudopodia encircle food and absorb it phagocytosis.

Amoeba: Shapeless Protists Most amoebas live in saltwater

environments, but some can be found in moist freshwater environments like in the ooze of ponds.

Amoeba: Shapeless Protists

There are two groupings of marine amoebas and both have shells made of silica. They make up an important part of marine plankton. 1. Foraminifera

2. Radiolarian

Amoebas: Shapeless Protists

Most amoebas commonly reproduce by asexual reproduction, in which a single parent produce one or more identical offspring by dividing into two cells.

Flagellates

Phylum Zoomastigina (zooflagelletes) Have one or more flagellum Move by whipping their flagellum from side to

side.

Flagellates

Some are parasites and cause disease in animals, such as Trypanosoma, which is transmitted by tsetse fly and can cause African sleeping sickness in humans

Flagellates

Some mutualistic species digest cellulose in the guts of termites.

Without these flagellate protozoans the termites would not be able to survive on their diet of wood.

Ciliates

Phylum Ciliophora (known as ciliates) Use cilia that cover their

bodies to move. Live in every kind of aquatic

habitat. Paramecium: Journal

Drawing (Refer to Page 507) Protozoan: A Paramecium Label and Define the

Functions Color

Ciliates Structure Cilia: the cell is encased by an outer covering

called a pellicle through which thousands of tiny, hairlike cilia emerge. The paramecium can move by beating its cilia

Oral Groove: bacteria that ciliates feed on are swept into the gullet by cilia that line the oral groove.

Gullet: Food moves into the gullet, becoming enclosed at the end in a food vacuole. Enzymes break down the food, and nutrients diffuse into the cytoplasm.

Ciliate Structure

Micronucleus and macronucleus: the small micronucleus plays a major role in sexual reproduction and the macronucleus controls the functions of the cell.

Anal Pore: waste material leave the cell through the anal pore

Contractile vacuole: because they live in hypotonic environments water is constantly entering the cell and they use these to pump water out.

Ciliate

Paramecium usually reproduce asexually by divide into two identical daughter cells.

Sporozoans: Parasitic

Phylum Sporozoa (called sporozoans) A spore is a reproductive cell that forms without

fertilization and produces a new organism. All sporozoans are parasites. They are usually found in a part of a host that has

a ready food supply (blood or intestines). Plasmodium, members of the sporozoan genus,

are organisms that cause the disease malaria in humans and other mammals and in birds.

Section 19.2: Algae

phytoplankton, thallus, colony, fragment, alternation of

generations, gametophyte, sporophyte

What are algae?

Photosynthesizing Contain up to four kinds of chlorophyll as well

as other pigments producing a variety of colors (purple, rusty-red, olive-brown, yellow, golden brown)

We use their pigments/colors to classify them into groups.

Unicellular and multicellular

What are algae?

Unicellular photosynthesizing protists are known as phytoplankton and are one of the major producers of nutrients and oxygen in aquatic ecosystems.

Multicellular algea look like plants because they are large and sometimes green, but they have no roots, stems, or leaves.

Diversity of Algae

Algae are classified into 6 phyla:1. Euglenoids

2. Diatoms

3. Dinoflagallets

4. Green Algae

5. Red Algae

6. Brown Algae

Euglenoids

Unicellular Aquatic Lack cell wall made of cellulose They have a flexible pellicle made of protein that

surrounds the cell membrane (similar to cell wall) Have chlorophyll to photosynthesize When light is not available they can ingest food

similar to protozoans. Use flagella to move

Journal Drawing

Find a euglenoid on a microscope slide and draw in journal

Also draw a large scale drawing from the book (Refer to pg. 511)

Label Answer in journal: What

is the significance of the eye spot?

Diatoms: The golden algae

Unicellular Photosynthetic Shells composed of silica Make up a large component of phytoplankton in

fresh and saltwater ecosystems. Contain chlorophyll and another pigments

called caratinoids that given them a golden-yellow color.

Diatoms: the golden algae

They store food as oil instead of starch and this is why fish have an oily taste.

This also make diatoms more buoyant, so they float near the surface.

Diatoms: the golden algae

Diatoms reproduce asexually, by forming halves smaller than themselves and then the smaller halves release sperm or eggs that can be fertilized externally by sexual reproduction to form a zygote.

Pg. 512 Figure 19.10 Journal Drawing: Observe Diatoms under the

microscope and draw in journal.

Dinoflagelletes: spinning algae

Cell walls composed of cellulose plates. Come in a variety of shapes and styles. Contain chlorophyll, carotenoids, and red

pigments. Two flagella located in grooves at right angles

to each other causing the cells to spin slowly. Most are marine and make up a large

component of phytoplankton. Some can be bioluminescent, which means

they emit light.

Dinoflagellates

Several species of dinoflagellates can produce toxin.

Gonyaulax catanella produces an extremely strong nerve toxin that can be lethal.

In the summer they can become so numerous that the ocean takes on a reddish color. This population explosion is known as red tide.

Dinoflagellates

The toxin produced during a red tide can make humans ill.

During red tides harvesting of shell fish is banned because they may feed on the toxic algae and the toxin can be passed to humans.

Problem-Solving Lab pg. 514 in journal

Red Algae

Phylum Rhodophyta Mutlicellular marine

seaweed The body of a seaweed

is called a thallus. Red algae use

structures called holdfasts to attach to rocks.

Red Algae

Contain chlorophyll and an additional pigment called phycobilins that absorbs wavelengths of light that penetrate below depths of 100m.

This is why we find red algae in deep waters where other seaweed cannot thrive.

Brown Algae

Phylum Phaeophyta Multicellular brown algae Most are found in marine environments along

rocky coasts in cool areas of the world. Contain chlorophyll as well as a yellowish-

brown carotenoid pigments called fucoxanthin, which gives them their brown color.

Brown Algae

Many species have air bladders that keep their bodies floating near the surface where light is available.

In kelp (the largest brown algae) the thallus is divided into the holdfast, stipe, and blade.

Journal Drawing: Brown Algae

Brown Algae

The holdfast anchors kelp to rock or sea floor.

The stipe is similar to a stem, the blades grow off the stipe.

Some giant kelp can grow up to 60 meters such as off the coast of California where they form large underwater forests and provide a habitat for a variety of marine organisms.

Green Algae

Phylum Chlorophyta The most diverse algae

with 7,000 species. The major pigment in

green algae is chlorophyll, but some can have a yellow-green color.

Most live in fresh water, but some live in the oceans, moist soil, on tree trunks, in snow, and even in the fur of sloths.

Green Algae

Can be unicellular, colonial, or multicellular in organization.

Chlamydomonas is a unicellular flagellated green alga.

Spirogyra is a multicellular speceis that forms slender filaments.

Green Algae

Volvox is a green alga that can form a colony, a group of cells that lives together in close association.

Volvox is composed of hundreds, or thousands, of flagellated cells arranged in a single layer forming a hollow, ball shaped structure.

The cells are connected by strands of cytoplasm, and the flagella of individual cells face outward, causing the colony to spin through the water.

Green Algae

http://videos.howstuffworks.com/hsw/8486-the-world-of-the-protozoa-volvox-video.htm

Green algae reproduce both sexually and asexually.

Spirogyra reproduce asexually by fragmentation. During fragmentation, and individual breaks up into pieces and each piece grows into a new individual.

Journal Drawing

Green Algae Observation Find Volvox and Spirogyra under the

microscope label and draw. Under each drawing explain how they

reproduce.

Green Algae

Green algae and some other types of algae have a complex life cycle.

This life cycle consists of individuals that alternate between producing spores and producing gametes.

This life cycle is known as alternation of generations.

Alternation of Generations

An organism that has this pattern alternates between existing as a haploid and a diploid organism, creating two different generations.

The haploid form of the organism is called the gametophyte, because it produces gametes which fuse to form a zygote.

The zygote is the diploid form of the organism, which is called the sporophyte.

Certain cells in the sporophytes will undergo meiosis that will develop haploid spores that can develop into new gametopytes.

Journal Drawing

Alternation of Generations Draw the life cycle and label (Refer to pg. 516

Figure 19.14 in book.

What you need to know…

Vocabulary General Characteristics of Protozoans and Algae Protozoans: Ameobas, Flagellates, Ciliates and

Sporozoans Plantlike: Euglenoids, Diatoms, Dinoflagellates,

Red, Brown, and Green Algae Species: Paramecium, Plasmodium, Euglena,

Gonyaulax catanella, Kelp, Chlamydomonas, Spirogyra, Volvox

Video

Review Video http://videos.howstuffworks.com/hsw/17420-li

fe-in-a-drop-of-water-protozoa-found-in-pond-water-1-video.htm