BIOLOGY (CH 3)

What are protoctista / protists?

A group of diverse eukaryotic, predominantly unicellular microscopic organisms.

They may share certain morphological & physiological characteristics with animals, plants, or fungi

What are microsporidia? (one of the most important protists to remember)

Unique, well-adapted pathogens, and important agricultural parasites that infect insects, allowing them to be used as insecticides

What are pathogens?

disease causing microorganism (ex: parasite, bacteria)

Protists are classified on their mode of...

nutrition

What are the 3 classifications of protists?

- Animal-like protists

- Plant-like protists

- Fungi-like protists

Animal-like protists are also known as...

Protozoa

Why are animal-like protists animal-like, and what are they classified based on..?

because they are heterotropic

classified based on method of movement

What are the 4 types of animal-like protists?

- Ciliates (Ciliophora)

- Amoeboid (Sarcodina)

- Sporozoan (Apicomplexa)

- Flagellate (Zoomastigina)

What are the characteristics of Ciliates (Ciliophora)?

- move using cilia

- they exhibit nuclear dimorphism (2 nuclei, large macronucleus involved in vegetative/life-sustaining functions of the organism, and a small micronucleus involved in sexuality)

- contain contractile vacuoles, that are responsible for osmoregulation (controls the intracellular water balance by accumulating and expelling excess water out of the cell

What's an example of Ciliates (Ciliophora)?

Paramecium

What's osmosis?

the movement of water molecules from a solution with a high concentration of water molecules to a solution with a lower concentration of water molecules, through a cell's partially permeable membrane.

What are the characteristics of Amoeboid (Sarcodina)?

- the cells crawl using pseudopods (false feet)

- pseudopods are also food-acquiring structures

- contain contractile vacuoles

What's an example of an Amoeboid (Sarcodina)?

Amoeba

What do we need to know about Foraminifera & Radiolaria?

They both belong to the amoeboid group.

geologists use the remnant fossils of foraminifera (capsules made up of calcium carbonate) in the process of dating rocks & sediments & identifying oil bearing rocks

What are the characteristics of Sporozoan (Apicomplexa)?

- they lack the organs that are responsible for movement and depend on gliding for movement

- doesn't have contractile vacuoles

What's an example of Sporozoan (Apicomplexa) and what does it cause?

Plasmodium Malariae , causes malaria in humans, transmitted via the female anopheles mosquito

What are the characteristics of Flagellate (Zoomastigina)?

- move through beating flagellum

What's an example of Flagellate (Zoomastigina) and what does it cause?

Trypanosoma, which causes

1. The American Sleeping Sickness (Chagas Disease) transmitted by the kissing bugs (Reduviidae)

2. The African Sleeping Sickness (East/West) transmitted by the Tsetse Fly (vector)

What is a vector in biology?

an organism that transmits something from one organism to another (like mosquitos)

What's another name for plant-like protists?

Algae

Why are they called plant-like protists?

they are photoautotrophic (use light to synthesize their own food, through photosynthesis)

contain chloroplasts

& a few more characteristics in common

Plant-like protists are classified into 7 groups which are..

- Diatoms

- Dinoflagellates

- Euglenoids

- Golden Algae (Chryophytes)

- Brown Algae

- Green Algae

- Red Algae

What are the characteristics of Diatoms?

- they have a specialized cell wall made of silica

- store food in the form of oils & not carbohydrates, allowing them to float in water, maximizing the amount of sunlight absorbed for photosynthesis

- Presence of Carotenoid Pigments, giving it a golden-yellow color

- Used in teeth whitening & polishing metal

What are the characteristics of Dinoflagellates?

- Motile (capable of movement) due to the presence of 2 flagella (biflagellate) , that are oriented in a perpendicular manner to each other

- Responsible for the Red Tide Phenomenon , that results from the overgrowth of these plant-like protists

Is the Red Tide Phenomenon good?

The Red Tide Phenomenon may look visually pleasing, but it can be toxic, as some of these dinoflagellates release toxins that destroy neurons in humans. This toxin gets into the human body due to eating crustaceans (ex: crabs) & oysters that eat the dinoflagellates in the water.

What are the characteristics of Euglenoids?

- Pellicle (basically cell-wall like structure) present instead of the cell wall

- Eyespot (light sensitive organelles) that detects light

- Have chloroplasts and contractive vacules (osmoregulation)

Why were Euglenoids classified as plant-like protists if they share characteristics with both animals & plants?

They were classified into plant-like protists because they photosynthesize since they have a chloroplast

What's an example of a Euglenoid?

Euglena Algae

What are the characteristics of Golden Algae (Chrysophytes)?

it includes both yellow-green algae & golden-brown algae that contain carotenoid pigments

What are the characteristics of Brown Algae?

it gets its brown color from a carotenoid pigment called Fucoxanthine

What are the characteristics of Green Algae?

- has a cellulose cell wall & chlorophyll

- stores food in the form of carbohydrates

What are examples of Green Algae?

- Spirogyra (spirally coiled, ribbon shaped chloroplast)

- Volvox

What are the characteristics of Red Algae?

- used in food

- helps build coral reef ecosystem

What's another name for Fungi-Like Protists?

Molds

What are the characteristics of Fungi-Like Protists (Molds)?

- Express heterotrophic nutrition (absorbing nutrients from decomposing or dead organic substances in their surroundings)

- They have a cellulose cell wall

What's an example of a Fungi-Like Protist (Mold)?

Slime Mold

What are the characteristics of Fungi?

- they are eukaryotic heterotrophic organisms

- food is broken down by enzymes before it's absorbed into their cells

- possess a cell wall made of up chitin, a strong & flexible polysaccharide. (it can also be found in the exoskeleton of insects & Arthropods)

What are the 2 types of fungi and their examples?

- Unicellular (ex: Yeast)

- Multicellular (ex: Mushrooms)

How do fungi reproduce?

- most reproduce sexually

- some reproduce asexually by spore production, budding (as seen in yeast), and fragmentation

What are the 3 main structures of fungi + their functions?

- Hyphae: releases digestive enzymes to absorb nutrients from food sources

- Mycelium: network of hyphae

- Fruiting Bodies: structure that produces spores

What are the 3 forms of nutrition for Fungi?

- Saprotrophic

- Parasitic

- Mutualistic

What's saprotrophic nutrition?

obtain food from dead & decayed materials (such as mushrooms)

What's parasitic nutrition?

feed off of living organisms (host) & then destroys them (or kills them)

What's mutualistic nutrition?

such as some types of fungi growing on roots of plants such as soybeans (they benefit each other)

Fungi are divided/classified based on...

their structure & mode of nutrition

What are the main divisions of fungi?

- Chytridiomycota (Chytrids)

- Zygomycota (Common Molds)

- Ascomycota (Sac Fungi)

- Basidiomycota (Club Fungi)

What are the characteristics of Chytridiomycota (Chytrids)?

- unicellular

- aquatic

- produce flagelleted zoospores

What's an example of Chytridiomycota (Chytrids)?

Allomyces (aka Water Mold)

What are the characteristics of Zygomycota (Common Molds)?

- Multicellular

- Mainly terrestrial (lives on land), lives in soil, compost, & some foods such as bread

- Undergo both sexual (produces zygospores) & asexual reproduction

- Arial Hyphae (grow in the air) spread across the surface of food

- Mycelium absorbs nutrients

What's an example of Zygomycota (Common Molds)?

Bread Mold

What are the characteristics of Ascomycota (Sac Fungi)?

- Most are multicellular

- Undergo both sexual (ascospores) & asexual reproduction

What are some examples of Ascomycota (Sac Fungi)?

Aspergillus & Yeast

What are the characteristics of Basidiomycota (Club Fungi)?

- Most are multicellular

- reproduce sexually by producing basidiocarps

What's an example of Basidiomycota (Club Fungi)?

mushrooms

What are the benefits of Fungi?

In medicine: Penicillin, an antibiotic is extracted from Penicillium

In food: mushrooms, truffles, & yeast (which is used in the production of many food products such as bread & cheese)

The presence of Lichens represents...

a mutualistic association of a fungus and a chlorophyll-containing partner( either green algae, cyanobacteria, or both)

What's a bioindicator?

an organism used as an indicator of the quality of an ecosystem, especially in terms of pollutions

Lichens are bioindicators because...

they are sensitive to environmental pollutants (air pollution) as they are readily affected by changes within the air

The presence of Mycorrhizae represents...

a mutualistic relationship between fungi & some plants (the roots of plants)

Fungi colonize the root system of a host plant by...

by providing increased water & mineral absorption capabilities by increasing the surface area of the roots

What does the plant provide the fungus with in Mycorrhizae?

plant provides fungus with amino acids & carbohydrates (glucose) formed from photosynthesis

The presence of Mycorrhizae is beneficial because...

they increase the crop yield of some plants such as corn, carrots, potatoes, tomatoes, & strawberries