Lecture 11 BIOL L100 Indiana University Southeast David Partin, Instructor - PowerPoint PPT Presentation

1 / 45
About This Presentation
Title:

Lecture 11 BIOL L100 Indiana University Southeast David Partin, Instructor

Description:

Carolus Linnaeus (aka Karl von Linne) Biological Classification of Humans. Phylogenetic tree ... extremely hot, acidic environments (geysers, hot springs, ... – PowerPoint PPT presentation

Number of Views:94
Avg rating:3.0/5.0
Slides: 46
Provided by: davidp58
Category:

less

Transcript and Presenter's Notes

Title: Lecture 11 BIOL L100 Indiana University Southeast David Partin, Instructor


1
Lecture 11BIOL L100 Indiana University
SoutheastDavid Partin, Instructor
2
Todays Plan
  • Announcements/Questions
  • Lecture 11 Origins Classification of Life
    Microbiology (Ch 19-21)
  • Video clips
  • One Minute paper
  • Lab
  • Introduce Case Study 5 HIV

3
Todays Topics
  • Ch19 Origin and History of Life
  • Ch20 Classification of Living Things
  • Ch21 Viruses/Bacteria/Archaea

4
Stanley Miller-1953
Primitive atmosphere containing methane, ammonia,
hydrogen and water vapor
Gases heated, closed system, passed through
electrical spark organic molecules
spontaneously form (amino nucleic acids)
5
Millers experiment attempted to start here.
6
Fossils provide evidence of prehistoric life.
7
Fossils tell a story of the history of life on
Earth. Relative dating- Use rock
layers Absolute dating- Use radioactive
isotopes like carbon-14 and potassium-40, etc.
8
Theory of Continental Drift-1920-Alfred
Wegener Evidence for Continental Drift? Plate
tectonics, fossils, geography, magnetism,
etc. Changes in continental positions had a
major effect on evolution of species.
9
The Earths crust is divided into plates that
move because of seafloor spreading at ocean
ridges.
10
Just for reference. Do not memorize!
11
Part IIClassification of Living Things
Think-Pair-Share How would you classify these
organisms into groups?
12
Carolus Linnaeus (aka Karl von Linne)
13
Biological Classification of Humans
14
Phylogenetic tree Phylogeny evolutionary
history of an organism
15
Anatomical evidence (fossils, skeletons, etc.) is
sometimes not enough to accurately construct an
organisms phylogenetic tree. These days,
molecular evidence is the final word.
16
(No Transcript)
17
More about these coming soon
see attached sheet for better view
Discussed today
18
(No Transcript)
19
(No Transcript)
20
Part I Viruses
  • Viruses are non-cellular
  • Viruses are not living organisms
  • Require a host for reproduction and maintenance
    (obligate intracellular parasites)
  • All viruses have at least 2 parts a protein
    capsid and an inner core of nucleic acid (either
    DNA or RNA)

21
Part I Viruses
  • Viruses are categorized by
  • Capsid shape
  • Type of nucleic acid
  • DNA or RNA
  • Single stranded or double stranded
  • Presence or absence of a membrane (envelope)

22
Part I Viruses
23
Part I Viruses
  • Viral
  • Reproduction I
  • Bacteriophages are viruses that infect bacteria.
    They reproduce by
  • Lytic cycle
  • Lysogenic cycle

24
Part I Viruses
Viral Reproduction II Animal viruses use cell
membranes as camouflage. New viruses are
released by budding.
25
Part I Viruses
  • Viral infections
  • Can lead to cancer
  • Papillomaviruses, herpes viruses, hepatitis
    viruses, adenoviruses
  • AIDS is caused by a retrovirus (HIV)
  • Antibiotics used to interfere with bacterial
    metabolism have no effect on viruses.

26
Side Note Viroids Prions
  • Viroids are naked strands of RNA that cause
    certain crop diseases
  • Prions are misfolded proteins that cause certain
    animal diseases
  • Creutzfeldt-Jacob Disease humans
  • Bovine Spongiform Encephalopathy (Mad Cow
    Disease) cattle
  • Scrapie sheep

27
Need a Break?
  • Meet back in 10 minutes
  • When we return
  • Bacteria
  • Archaea

28
Part II Prokaryotes
  • Both Bacteria and Archaea are prokaryotes
  • Prokaryotes lack a nucleus and most other
    organelles found in eukaryotic cells
  • Prokaryotes reproduce asexually by binary fission
  • Genetic variation occurs mainly by mutations, but
    also through conjugation, transformation and
    transduction.

29
Part II Prokaryotes
  • Never seen until 1600s
  • Anton von Leeuwenhoek scraped his teeth and
    viewed little animals under the microscope
  • Spontaneous generation was credited until Louis
    Pasteurs 1850 experiment

30
Part II Prokaryotes
31
Part II Prokaryotes
(outside)
Structure
-DNA
-photosynthesis
(inside)
-locomotion
-DNA swapping
(attached to outside)
-locomotion/ stability
32
Part II Prokaryotes
? flagella
33
Part II Prokaryotes
  • Reproduction binary fission (aka cloning, 1
    splitting into 2, etc.)
  • Reproduction can occur as often as every 12
    minutes in the right conditions.
  • Because reproduction is so quick, more genetic
    mutations (mistakes) are made.
  • Haploid (1 copy) so genetic mutations are
    subjected to natural selection immediately

34
Part II Prokaryotes
Only 1 chromosome Thats NOT the only DNA found
in bacteria. They also have very small pieces of
circular DNA free in the cell, called plasmids.
Genes for antibiotic resistance are usually found
on plasmids.
35
Part II Prokaryotes
  • Reproduction is asexual, but 3 methods of genetic
    recombination exist.
  • 1. conjugation-one bacterium passes DNA through
    sex pilus to a 2nd bacterium
  • 2. transformation-bacterium picks up free pieces
    of DNA from environment
  • 3. transduction-bacteriophages pass small pieces
    of bacterial DNA
  • Note plasmids can be passed from one bacterium
    to another by any of these means.

36
Part II Prokaryotes
  • Prokaryotes can survive very harsh conditions by
    forming spores.
  • Cell dehydrates, leaving only a small portion of
    cytoplasm and the chromosome surrounded by 3
    thick layers of spore coat.
  • Can survive desert heat, arctic ice, boiling
    water, and timethousands of years!

37
Part II Prokaryotes
  • Oxygen requirements
  • Most prokaryotes require oxygen to survive
  • Obligate aerobes
  • Some can live with or without oxygen
  • Facultative anaerobes
  • Some are poisoned by oxygen
  • Obligate anaerobes

38
Part II Prokaryotes
  • Bacteria are the more common type of prokaryotes
  • Groups of bacteria are often differentiated from
    one another using the Gram staining technique
    that we will use in lab today.
  • Different types of bacteria stain differently
    because of the differences in the structure of
    their cell walls. More about this later

39
Part II Prokaryotes
  • Bacteria are usually discussed concerning
    infections, but they serve some very useful
    purposes.
  • Some are photosynthetic, producing oxygen.
  • Some are useful for decomposition.
  • Some aid in digestion.
  • Nitrogen-fixation in plant root nodules.

40
Part II Prokaryotes
  • Archaea are discussed in terms of their unique
    habits.
  • Methanogens live in anaerobic environments
    (swamps, intestinal tracts) and produce methane
    gas
  • Halophiles live in extremely salty environments
  • Thermoacidophiles live in extremely hot, acidic
    environments (geysers, hot springs, thermal
    vents, around volcanoes)
  • Believe it or not! Archaea are genetically more
    similar to eukaryotes than bacteria!

41
Bioterrorismpathogens used as weapons
  • Anthrax- caused by bacterium Bacillus anthracis
  • Easy to acquire grow
  • 2 forms inhaled cutaneous
  • Flulike symptoms, death within 24-72 hrs from
    bacterial toxins
  • Not contagious
  • Treated with strong antibiotics
  • Smallpox- caused by variola virus
  • Highly contagious, airborne virus
  • Fever, headache, aches, rash
  • Not likely to be diagnosed until full-blown
  • Eliminated??
  • Plague- caused by bacterium Yersinia pestis
  • Bubonic plague-bite of infected flea
  • Pneumonic plague- inhaled (more favored by
    terrorists)
  • Immediate treatment required or death from
    respiratory distress
  • Botulism- caused by toxins of bacterium
    Clostridium botulinum
  • Food-borne
  • Difficulty seeing, talking, swallowing within 24
    hrs, respiratory failure
  • Tularemia- caused by bacterium Francisella
    tularensis

Possible essay question
42
Side Note Diseases in Humansviral vs. bacterial
43
Thanks for your attention!
  • Take a break if you need one!
  • Whats next?
  • Video clips
  • One-minute paper
  • Lab

44
Overview of todays lab
  • Gram Staining
  • Lets read p73-74 together (lab manual)

45
Preparation for Lecture 12
  • Skim chapters 22 23
  • Keep up with your Oncourse quizzes.
Write a Comment
User Comments (0)
About PowerShow.com