Bio test 4 (lectures 17-20)

Archaea

• prokaryotes without peptidoglycan in their cell walls

• Inhabitants of extreme environments (very hot or acidic)

• Not inhibited by antibiotics

Methanogens

Strict anaerobes, decomposers in sewer systems, produce methane gas

Extreme Halophiles

Thrive in high salt environments. Some are photosynthetic with purple pigment

Extreme Thermophiles

Live in very hot environments. Some can produce sulfuric acid from sulfur.

Domain Bacteria

• Prokaryotes with typical peptidoglycan in their cell walls

• Survive in ordinary environments

• Mostly inhibited by antibiotics

Gram positive bacteria

With thick peptidoglycan (approximately 60-90% of cell walls is peptidoglycan)

Gram negative bacteria

With thin peptidoglycan (10-20%) with thin lipid layer on top. More resistant to antibiotics and drugs.

Cyanobacteria

Photosynthetic blue green bacteria in aquatic environments that can fix atmospheric Nitrogen

Spirochetes

Long spiral bacteria, some are agents of STD’s

Mycoplasmas

• The only bacteria without cell walls

• Hard to grow in artificial medium

• Can cause a mild form of pneumonia

Chlamydia and Rickettsiae

• obligate parasite

• Thought to be virus until scientists found out they are made up of cells

What is the process of transformation

Small pieces of “naked” DNA in the environment are taken up by bacterial cells

Where does transformation occur

Only at a certain stage of growth (I.e., before completion of cell wall)

What parts can get into host cell during transformation

Plasmids and parts of chromosomes from dead cells can get into host cell.

Transduction

Process by which DNA is transferred from a bacteriophage (virus that infects bacteria) to a bacterial cell.

What is conjugation

Bacterial mating

What happens in conjugation

Direct transfer of DNA from one bacterial cell to another via conjugation pilus (F-pilus)

Where does conjugation occur

Usually between two related bacteria but even unrelated bacteria can mate

What is required for conjugation

Contact between donor and recipient cell

Kingdom Protista

Kingdom for extra organisms

Amoeba habitat

Bottom of ponds, contaminated water, some are parasitic

Amoeba shape

Fried egg

How do amoeba move

Extending their pseudopodia (false feet) in one direction and then pouring contents of the cytoplasm in that direction

Euglena

Includes unicellular eukaryotes with no true mitochondria and those with unique flagella

Euglena habitat

Polluted fresh water

Are euglena photosynthetic

When light is present, they are photosynthetic. When light is absent, they become heterotrophic.

Cilates

Largest group of Protozoa that are involved in cleaning the environment

How do ciliates move

Move by cilia (hair-like projections) all over the cells

What do ciliates feed on

Bacteria, fungi, and other pollutants

Dinoflagellates

Named after whirling motion due to two flagella (one extends like a tail, the other lies in a transverse grove like a belt)

Considered a unicellular algae

Example of euglena

Trypanosoma, giardia, trichomonas

Examples of ciliates

Paramecium

Example of dinoflagellates

Gonyaulax

Diatoms

Non-motile, UNICELLULAR ALGAE with glass-like appearance due to silica in the cell wall

Where are diatoms used?

• Used in industry as abrasives for toothpastes, and gloss for paints

• Gives fishy taste to fish

Kingdom fungi

Eukaryotes with cell wall made out of chitin

Heterotrophs

Not capable of photosynthesis and rely on other organisms for food

Ascomycetes (sac fungi)

Fungi born in a sac like structure called ASCUS. Usually 8 spores inside an ascus

Examples of sac fungi

Cup fungi, morels, apple scab pathogen

Club fungi

• fungi with spores that are borne in a “club” - like structure (similar to baseball bat)

• ALL TRUE mushrooms with a basidiocarp (cap) belong here

• Certain kinds of plant pathogens also belong to this group

Examples of club fungi

• amanita muscaria (hallucinogenic) mushroom that produces LSD-like substances

• Amanita pantheria which is highly toxic and fatal

Imperfect fungi

These are fungi without known sexual stage; just a transition group; reclassified once sexual stage is identified

Kingdom plantae

• multicellular eukaryotes with cell wall of cellulose

• Capable of photosynthesis

• Store energy in form of starch

What is algae

• aquatic plants

• Absence of roots

• First plants to evolve

Green algae

• modern day plants evolved from this group

• Green chlorophyll

Green algae habitat?

Fresh water or marine

Red algae

• Some are red, purple, green/black

• Typically filamentous and branched

Where can red algae survive

Can survive in greater depth of water due to pigment phycoerythrin which absorbs blue like waves that can penetrate deeper

How is red algae used

Source of “agar” which is used as solidifying agent in desserts and “nori” Seaweed

Brown algae

• olive green, gold, brown

• Pigment fucoxanthin

• Branched, filamentous bodies

Brown algae is also called what?

Kelps

What does brown algae produce

“Algin” which is used as a thickener, emulsifier, suspension agent in pudding, salad dressing, toothpaste, cough syrup

Bryophytes

Non-vascular (no true leaves, roots, stems) plant plants. They have “rhizomes” instead of roots

What do bryophytes need for sexual reproduction

Liquid water

Where do bryophytes live

Moist, damp environments

Examples of Bryophytes

Liverworts and mosses

Pterophytes

• vascular plants (with leaves and stems), no seeds but produce by spores

Pterophytes