Bacteria, Protists, and Fungi

Question 1

“…evolution produces a tree, not a ladder — and we are just one of many twigs on the tree.”

Answer 1

Phylogenetic trees depicts the evolutionary relationships of about 3,000 species throughout the Tree of Life. Less than 1 percent of known species are depicted.

Question 2

Domain

Answer 2

the highest level of hierarchy

Three domains:
Bacteria, Archaea, and Eukarya

Question 3

Bacteria

Answer 3

no nucleus, single-celled

PROKARYOTES

Question 4

Archaea

Answer 4

no nucleus, single-celled

PROKARYOTES

Question 5

Eukarya

Answer 5

have a nucleus
cells can be either single-celled or multicelled

EUKARYOTES

Question 6

The origin of prokaryotes

Answer 6

At least 3.6 billion years old
Fossil stromatolites (still can be found today); consist of layers of bacterial mats.
First prokaryotes likely appeared much earlier.

Early photosynthetic prokaryotes produced an oxygen atmosphere.

Question 7

Most common form of movement in prokaryotes

Answer 7

Flagella

Question 8

Prokaryotes Disease: cause about half of all human diseases

Answer 8

TB (Mycobacterium tuberculosis)*
Cholera (Vibrio cholerae) outbreaks in untreated water
Syphilis (Treponema pallidum)* why easily treated
Lyme disease (Borrelia burgdorferi)* most widespread pest-carried disease in U.S.
Anthrax (Bacillus anthracis)
Legionnaire’s disease (Legionella sp.)
Escherichia coli (part of our natural gut flora, but type O15:H7 is dangerous.)
Plague (Yersinia pestis)

Question 9

Syphilis

Answer 9

Bacterial Disease
Syphilis can be easily treated with antibiotics, usually by injections.
Gonorrhea (Neisseria gonorrhoeae)
Strep infection (Streptococcus sp.)
Chlamydia trachomatis* most common STD
Clostridium botulinum*  BOTOX 
MRSA (now VRSA?)

(BUT Harmful prokaryotes are in the minority)

Question 10

Prokaryotes: What we don’t think of

Answer 10

Collective mass is 10 times of eukaryotes
If reproduction unlimited colony could outweigh Earth in 3 days.
Differences between bacteria and eukaryotes allow antibiotics to
disrupt RNA and ribosomes (erythromycin and tetracycline)
disrupt bacterial cell walls

Question 11

Prokaryotes: What we don’t think of

Answer 11

Collective mass is 10 times of eukaryotes

If reproduction was unlimited colony could outweigh Earth in 3 days.

Differences between bacteria and eukaryotes allow antibiotics to disrupt RNA and ribosomes (erythromycin and tetracycline) and to disrupt bacterial cell walls.

Question 12

Bacteria

Answer 12

All share a common ancestor
Originated ~ 3.8 billion years ago

Single-celled prokaryotes

Asexual reproduction
Also exhibit horizontal gene transfer

Question 13

Bacterial Classification

Answer 13

3 basic shapes:
Coccus (round)
Bacillus (rod)
Spirillum (spiral)

Gram Staining differentiates between 2 major groups based on cell wall structure:
Gram-Positive
Gram Negative

Question 14

Humans and Bacteria

Answer 14

There are 10 times as many bacterial cells in your body than human cells!

There are more bacterial cells in your stomach than there are people on the planet

Question 15

Benefits of Bacteria

Answer 15

“normal flora”

Probiotic therapy: swamp your body with benign/helpful bacteria to outnumber harmful bacteria fight bacteria with bacteria

Question 16

Thermus aquaticus

Answer 16

One of the most important bacterial discoveries
Used in polymerase chain reaction (PCR)
Found in hot springs

Question 17

Future Possibilities

Answer 17

Bacteria as data storage
http://news.discovery.com/tech/biotechnology/bacteria-work-as-hard-drives-110110.htm

Detecting Landmines
http://www.treehugger.com/clean-technology/scientists-create-bacteria-that-lights-up-around-landmines.html

Question 18

Archaea

Answer 18

Similarities with bacteria:
appearance
prokaryotes
single-celled

Big differences with bacteria:
DNA
cell wall chemical composition
flagella

Question 19

Archaea cont…

Answer 19

“Extremophiles”

• hydrothermal vents
• acidic water
• salty water
• places in which most proteins would denature

Found almost everywhere, including in your intestines:
break down bonds in beans, release methane

Question 20

Bells and Whistles of Eukarya

Answer 20

Nucleus

Cytoskeleton:
Controls shape of cell and movement of internal elements

Mitochondria:
Allow oxidative metabolism

Chimeric genome:
Some genes from Bacteria, some from Archaea, and some unique to Eukarya.
(for some, chloroplasts)

Question 21

In the course of evolution, genomes grow. HOW?

Answer 21

Eukaryotes typically have 5-20X number of genes of prokaryotes

New genes arise by duplication of existing genes– with subsequent divergence of function

Question 22

the constraints on single cells

Answer 22

Cells must stay small because of

1. water
2. nutrients
3. wastes

Question 23

Tissues

Answer 23

Tissues are not just aggregations of cells – the cells in tissues are connected by intercellular junctions and function as a unit

Junctions hold cells together and also allow communication between cells (e.g., transfer of small molecules)

Question 24

The evolution of multicellularity

Answer 24

Likely began with coloniality with subsequent cell specialization.

Coloniality has evolved independently in many prokaryote and protist lineages.

Multicellularity has evolved independently in several eukaryote groups.

What is significance of independent development?

Question 25

Protists

Answer 25

Extremely diverse Share one feature: eukaryotic Defined by exclusion: They just do not belong to any other kingdom. Classification is being reconsidered; there may be as many as 20 kingdoms

Question 26

Protist diversity

Answer 26

Range from single-celled protists to enormous multicellular organisms (algae) “Protists” exhibit wide range of “body plans” and include the most complex living cells

Question 27

Protist Classification

Answer 27

``` “Traditional” groupings: Animal-like protists – protozoans (chemoheterotrophs) Plant-like protists – algae (photoautotrophs) Fungus-like protists – molds Chemoheterotrophs (often saphrophytic-[feeds on dead or decaying matter]) ```

Question 28

chemoheterotrophs

Answer 28

An organism deriving energy by ingesting intermediates or building blocks that it is incapable of creating on its own. Most chemoheterotrophs obtain energy by ingesting organic molecules like glucose. ``` Word origin: Gk: Chemo = chemical, hetero = (an)other, troph = nourishment Related forms: chemoheterotrophic (adjective) ``` Also called: chemotrophic heterotroph Chemotrophs are organisms that obtain energy by the oxidation of electron donors in their environments. These molecules can be organic or inorganic. The chemotroph designation is in contrast to phototrophs, which utilize solar energy.

Question 29

protozoans

Answer 29

Animal-like protists; | chemoheterotrophs

Question 30

algae

Answer 30

Plant-like protists; | photoautotrophs

Question 31

molds

Answer 31

Fungus-like protists; | Chemoheterotrophs (often saphrophytic)

Question 32

Protist Classification

Answer 32

“Traditional” groupings: Animal-like protists – protozoans (chemoheterotrophs) Plant-like protists – algae (photoautotrophs) Fungus-like protists – molds Chemoheterotrophs (often saphrophytic-[feeds on dead or decaying matter])

Question 33

chemoheterotrophs

Answer 33

An organism deriving energy by ingesting intermediates or building blocks that it is incapable of creating on its own. Most chemoheterotrophs obtain energy by ingesting organic molecules like glucose. ``` Word origin: Greek: Chemo = chemical, hetero = (an)other, troph = nourishment Related forms: chemoheterotrophic (adjective) ``` Also called: chemotrophic heterotroph Chemotrophs are organisms that obtain energy by the oxidation of electron donors in their environments. These molecules can be organic or inorganic. The chemotroph designation is in contrast to phototrophs, which utilize solar energy.

Question 34

photoautotrophs

Answer 34

An organism obtaining energy from sunlight as its source of energy to convert inorganic materials into organic materials for use in cellular functions such as biosynthesis and respiration. In order to capture light as source of energy, photoautotrophs carry out photosynthesis, converting energy from sunlight, carbon dioxide and water into organic materials. Photoautotrophs provide nutrition for many forms of life. They include the plants, algae and certain protists bacteria. ``` Word origin: Greek: photo = light, auto = self, troph = nourishment Related forms: photoautotrophic (adjective) ```

Question 35

“Plant-Like” Protists

Answer 35

Algae: photosynthetic protist living in water Range in size Use different photosynthetic pigments: yellow, gold, brown, red and green

Question 36

Seaweed

Answer 36

Plant-like protists a macroscopic, multicellular, benthic marine algae Used as a source of food for humans: Sherberts, chocolate milk, cheeses, instant pudding, mayonnaise, ice cream, etc Used in fertilizer, soil conditioner, animal feed, facial mask, massage gel, vitamins, seaweed baths, toothpaste, make-up, soaps, shampoo, shaving cream, shower gel.....

Question 37

“Fungus-Like” Protists

Answer 37

Plasmodial Slime Molds Cellular Slime Molds Slime Mold

Question 38

“Animal-Like” Protists

Answer 38

Most are unicellular Giardia Chagas disease African sleeping sickness Malaria

Question 39

Fungi: Basics

Answer 39

Domain: Eukarya Kingdom: Fungi Similar to plants, but - lack chloroplasts - do not photosynthesize - some are unicellular (ex: yeast) - heterotrophic (mostly decomposers)

Question 40

fungi are more closely related to

Answer 40

animals than plants

Question 41

Relationship of Fungi to Animals

Answer 41

Molecular genetic studies suggest fungi share a common ancestor with animals Features shared with animals: Cells walls contain chitin (as in some animals), not cellulose (as in plants) Carbohydrates stored as glycogen (as in animals) and not as starch (as in plants)

Question 42

Currently, 5 phlya of fungi

Answer 42

Chytrids (water and soil) Zygomycetes (rot produce, fast growing) Glomeromycetes (90% of plants have these on roots) Ascomycetes (morels, truffles, bread molds, yeast) Basidiomycetes (toadstools)

Question 43

Fungi feeding

Answer 43

Absorptive heterotrophs (like many prokaryotes) “Digest then ingest” - digestive enzymes secreted into surroundings; fungus then absorbs the digested products Most are decomposers: Some are parasitic, and some symbiotic

Question 44

Fungi: Structure

Answer 44

The body of most fungi is a network of thin filaments which - provides a large surface area for absorbing nutrients - penetrates the fungus’s food source - secrete enzymes that break down organic molecules - absorb resulting nutrients

Question 45

hyphae

Answer 45

tiny filaments of fungi that form a network underground and a “body” above

Question 46

mycelium

Answer 46

the interwoven network of hyphae | underground (or in a substrate)

Question 47

sporulation

Answer 47

the release of spores

Question 48

hyphae

Answer 48

tiny filaments of fungi that form a network underground and a “body” above

Question 49

mycelium

Answer 49

the interwoven network of hyphae underground (or in a substrate)

Question 50

Fungi: Chytrids

Answer 50

primitive fungi that produce swimming spores - flagellum Chytridomycota: Killing The Frogs

Question 51

Zygomycota

Answer 51

Ruining Your Food

Question 52

Glomeromycota

Answer 52

The Feeling is Mutual Mycorrhizal fungi form symbiotic relationships with plant roots. - Helps plant better absorb nutrients - Fungus gets carbohydrates from plant - mutually beneficial relationship - very common

Question 53

Essential ECOLOGICALLY: Glomerocytes and mycorrhizae

Answer 53

Associated with > 90% of plants. Improve water/mineral uptake by plant roots. Plant roots provides carbohydrates to fungus. ALL glomerocytes form arbuscular mycorrhizae.

Question 54

Ascomycota

Answer 54

"Bringing Friends Together" Important ECONOMICALLY Saccharomyces cerevisiae = Ascomycete yeast: - single-celled fungus - mostly asexual - inhabits liquid or moist environments - responsible for bread and wine and beer ``` Important GASTRONOMICALLY Some of the most famous edible mushrooms are ascomycetes - Morels - Truffles - Other molds in cheeses ```

Question 55

Ascomycota

Answer 55

"Bringing Friends Together" Important ECONOMICALLY Saccharomyces cerevisiae = Ascomycete yeast: - single-celled fungus - mostly asexual - inhabits liquid or moist environments - responsible for bread and wine and beer ``` Important GASTRONOMICALLY Some of the most famous edible mushrooms are ascomycetes - Morels - Truffles - Other molds in cheeses ``` Important MEDICALLY (good and bad) - Penicillium mold (ascomycete) - the source for penicillin, the first antibiotic. Alexander Flemming, Nobel Prize in 1945 for discovery of penicillen - Claviceps purpurea, which infects rye plants, is responsible for ergot poisoning. - Vaginal yeast infection (Candida albicans)

Question 56

Basidiomycota

Answer 56

Tasty, Fun or Deadly? toadstoals

Question 57

Fungi: Lichens

Answer 57

Relationship between a fungus and photosynthesizer (green algae or cyanobacteria) Can live in extreme conditions and is important in making soil, but is sensitive to pollution Fungus provides protected environment and minerals for the autotrophs, while the autotrophs supply carbohydrates Lichens often the first colonizers of bare rock and are likely one of the first land colonizers Can resist harsh, exposed conditions