Bacteria

1
Bacteria Protists

• Labs 14

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Species Names

• Taxon (plural, taxa) a group of organisms at a
  particular level of classification.
• Taxonomy the branch of biology that identifies
  and names groups of organisms.
• No two organisms can have the same name.
• The scientific name for an organism is the same
  all over the world.
• This avoids confusion that occurs with variable
  common names.

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Species Names

• The first name used in the binomial name is the
  genus.
• Genus name is always capitalized.
• The second name used is the species.
• Species names are never capitalized.
• Both names are italicized.
• Homo sapiens
• Genus species together are called the
  scientific name.

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Higher Categories

• Similar genera are grouped into a Family.
• Similar families are grouped into an Order.
• Similar orders are grouped into a Class.
• Similar classes are grouped into a Phylum (or
  Division in plants).
• Similar phyla are grouped into a Kingdom.

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Higher Categories

• Kindly Kingdom
• Purchase Phylum
• Cookies Class
• Only Order
• From Family
• Girl Genus
• Scouts Species

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Domains

• Three domains are now recognized
• Archaebacteria
• Eubacteria
• Eukarya
• Animalia
• Plantae
• Fungi
• Protista (very diverse, mostly unicellular group).

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Bacteria

• Prokaryotes lack organelles.
• Bacteria are the simplest forms of life.
• Bacteria contain DNA, but it is not contained in
  a nucleus.
• Bacteria reproduce by fission they simply split
  in two.

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Bacteria

• Most bacteria are saprotrophic they send out
  digestive enzymes into the environment and then
  take up the nutrient molecules.
• Some bacteria are parasitic and cause disease.

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Bacteria

• Others are photosynthetic or chemosynthetic
  making organic (food) molecules from inorganic
  molecules.
• A colony contains cells that are all descended
  from one original cell.

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Shapes of Bacteria

• Bacteria come in 3 shapes
• Bacillus (rod)
• Coccus (round)
• Spirillum (spiral)

Images by Biodisc company.
11
Bacterial Structure

• Basic structure includes a loop of DNA,
  ribosomes, a plasma membrane, a cell wall,
  sometimes a capsule.
• Some bacteria move about using a flagellum.
• Pili are used for attachment.

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Cyanobacteria

• Cyanobacteria are a kind of photosynthetic
  bacteria.
• They do not have chloroplasts, but they do have
  thylakoid membranes, where photosynthesis occurs.

http//www-cyanosite.bio.purdue.edu/index.html
Gloeocapsa sp.
Anabaena sp.
Oscillatoria sp.
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Protists

• Protists are eukaryotes that are not plants,
  animals, or fungi.
• Very diverse, catch-all kingdom.
• Mostly single-celled, few are commonly
  multicellular during part of their lives.

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Cell Surface

• All protists have a plasma membrane.
• Some, like algae, have cell walls.
• Others, like diatoms, have glassy shells of
  silica.

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Locomotor Organelles

• Movement is achieved usually either by
• Flagella or cilia or Pseudopods
• http//www.youtube.com/watch?vBR8xDBJOMyMNR1
• http//www.youtube.com/watch?vzTFsn9xt7b0

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Cyst Formation

• Many protists are successful in harsh habitats.
• Many have the ability to form cysts dormant
  form of the cell with a resistant outer covering,
  metabolism slows or shuts down.
• Cysts can be resistant to a variety of harsh
  conditions, desiccation, acid environment etc.

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Nutrition

• Protists can obtain their food in a wide variety
  of ways
• Photosynthetic autotrophs use energy from the
  sun to make food.
• Phagotrophs ingest visible particles of food.
  http//www.youtube.com/watch?vYHb2JaujIPo
  http//www.youtube.com/watch?vW6rnhiMxtKUNR1
• Osmotrophs ingest food in a soluble form.

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Reproduction

• Protists usually reproduce asexually except in
  times of stress.
• Asexual reproduction involves a modified version
  of mitosis.

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Colonies

• Colonial organism collection of cells that are
  permanently associated but with little or no
  integration of cell activities.
• Volvox individual motile cells form a hollow
  ball that moves by coordinated beating of
  flagella. http//www.youtube.com/watch?vR0Y7k4gOY
  kofeaturerelated

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Aggregates

• Aggregation a more transient collection of
  cells that come together for a period of time and
  then separate.
• Cellular slime molds usually feed as
  amoeba-like single cells. When bacteria are
  scarce, all individuals in an area aggregate into
  a large moving mass of cells called a slug.

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Multicellularity

• True multicellularity activities of the
  individual cells are coordinated and the cells
  themselves are in contact.
• Occurs only in eukaryotes.

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Multicellularity

• Multicellularity has been independently attained
  in 3 groups of protists.
• Brown algae (Phylum Phaeophyta)
• Red algae (Phylum Rhodophyta)
• Green algae (Phylum Chlorophyta)

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Classifying Protists

• The Kingdom Protista is an artificial group that
  does not represent evolutionary relationships.
• Phyla within Protista are only distantly related
  to each other.

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Heterotrophs with No Permanent Locomotor Apparatus

• Amoebas Phylum Rhizopoda.
• No flagella or cell walls.
• Move using pseudopodia flowing projections of
  cytoplasm.

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Heterotrophs with No Permanent Locomotor Apparatus

• Forams Phylum Foraminifera.
• Rigid shells called tests built of calcium
  carbonate and may be brightly colored.
• Move by cytoplasmic streaming. Podia extend
  through pores in the test and are used for
  swimming and prey capture.

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Heterotrophs with No Permanent Locomotor Apparatus

• Radiolarians Phylum Actinopoda.
• Unusual kind of amoeba with glassy skeletons and
  needle-like pseudopods.

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Heterotrophs with Flagella

• Zoomastigotes Phylum Sarcomastigophora.
• All are unicellular, have flagella and are
  heterotrophs.
• Trypanosomes are human pathogens that cause
  sleeping sickness.

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Heterotrophs with Flagella

• Ciliates Phylum Ciliophora.
• Unicellular heterotrophs with many cilia.

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Nonmotile Spore-Formers

• Sporozoans Phylum Apicomplexa.
• Nonmotile, spore-forming unicellular parasites.
• Includes Plasmodium, which causes malaria.
• Forms cysts resistant to desiccation or other
  harsh environments.

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Photosynthetic Protists

• Dinoflagellates Phylum Pyrrhophyta.
• Photosynthetic, unicellular, with 2 flagella in
  perpendicular grooves.
• Some are luminous.
• http//www.youtube.com/watch?vEN1Yxq8KMswfeature
  related

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Photosynthetic Protists

• Some dinoflagellates produce powerful toxins and
  are the cause of red tides population
  explosions of toxic dinoflagellates.

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Photosynthetic Protists

• Euglenoids Phylum Euglenophyta.
• Freshwater protists with 2 flagella.
• 1/3 have chloroplasts and are photosynthetic.
• The others are heterotrophic.

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Photosynthetic Protists

• Diatoms Phylum Chrysophyta.
• Photosynthetic, unicellular, with a unique double
  shell of silica.

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Photosynthetic Protists

• Green Algae Phylum Chlorophyta.
• Multicellular Unicellular examples.
• Chlorophyll a b in chloroplasts like plants.
• Some motile, some not.

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Photosynthetic Protists

• Red Algae Phylum Rhodophyta.
• Red pigments called phycobilins.
• Mostly multicellular and marine.
• Can grow at greater depth than other
  photosynthetic organisms.

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Photosynthetic Protists

• Brown Algae Phylum Phaeophyta.
• All multicellular, mostly marine.
• Contains the longest, fastest growing, most
  photosynthetically productive organism giant
  kelp.

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Heterotrophs with Restricted Mobility

• Slime molds water molds are often confused with
  fungi.
• Cell walls of cellulose rather than chitin like
  in fungi.

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Heterotrophs with Restricted Mobility

• Cellular slime molds Phylum Acrasiomycota.
• Closely related to amoebas.
• Can aggregate in times of stress to form a slug.

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Heterotrophs with Restricted Mobility

• Plasmodial slime molds Phylum Myxomycota.
• Plasmodium a nonwalled multinucleate mass of
  cytoplasm which can flow around obstacles or
  through cloth.

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Heterotrophs with Restricted Mobility

• Water molds Phylum Oomycota.
• Downy mildews seen in moist environments.
• Spores are motile with 2 flagella.
• Many are important plant pathogens.
• One causes late blight in potatoes which was
  responsible for the Irish potato famine of
  1845-47.