Bacteria: The Monera Kingdom • Bacteria are classified into two groups: Eubacteria (true bacteria) and Archaebacteria (Ancient Bacteria). • They are autotrophic or heterotrophic • most numerous organisms on earth • simplest and smallest organisms. • they are now part of nearly every environment on Earth. • found at the bottom of the oceanic trenches and in Arctic and Antarctic Regions. • about 2.5 Billion Years Old and Modern Humans arose about 100,000 years ago. • organisms are classified as Bacteria by having only one characteristic : they lack a nucleus.
Transcript
Bacteria: The Monera Kingdom• Bacteria are classified into two groups:
Eubacteria (true bacteria) and Archaebacteria (Ancient Bacteria).
• They are autotrophic or heterotrophic• most numerous organisms on earth• simplest and smallest organisms.• they are now part of nearly every
environment on Earth. • found at the bottom of the oceanic
trenches and in Arctic and Antarctic Regions.
• about 2.5 Billion Years Old and Modern Humans arose about 100,000 years ago.
• organisms are classified as Bacteria by having only one characteristic : they lack a nucleus.
layers) - help evade immune system, adhere to surfaces and prevents from drying out.
• endospores - bacteria become dormant until conditions become favorable
Movement of Bacteria
• flagella - one or more whip-like structures that beat their way through the water.
• Spiral their way through the water like a corkscrew.
Gram Stain
• Gram's Stain is a method of staining bacteria as an aid to their identification. It was originally devised by Hans Christian Joachim Gram, a Danish doctor.• Gram Negative -- light red or pink color
• Gram Positive -- dark purple
Gram Negative
Gram Positive
Reproduction
• Binary fission - one cell splits into two cells,
• Conjugation - bacteria exchange genetic information before dividing, offspring have new genes (and new traits)
• Transformation - bacteria incorporate genes from dead bacteria
• Transduction - viruses insert new genes into bacterial cells.
Binary fission
Conjugation
Transformation
Transduction
VirusesSome properties of viruses• posses no membranes,
cytoplasm, ribosomes, or other cellular components
• they cannot move or grow • they can only reproduce
inside a host cell • they consist of 2 major parts -
a protein coat, and hereditary material (DNA or RNA)
• they are extremely tiny, much smaller than a cell and only visible with advanced electron microscopes.
Review the structure of DNA
• Recall that DNA is a double helix molecule. It is composed of
alternating sugars (deoxyribose) and phosphates.
• The "rungs" of the ladder are made of nucleotides: adenine, thymine, guanine and cytosine.
• These nucleotides make up the genetic code - or blueprint- for the organism.
• Viruses are made of DNA and a protein coat, since they do not actually grow, reproduce (on their own) or carry out other life functions, they are not considered to be living organisms
Host of Viruses• Viruses are specific to
their hosts. They can only attack specific cells, and not all viruses can pass between different species (though some can). Rabies, for instance, can be passed from animal to human. HIV is a virus that seems specific to humans.
T-Even virus attacking a cell
Common Cold & HIV• The common cold is a
virus that specifically attacks cells of the respiratory track (hence the coughing and sneezing and sniffling).
• Other viruses attack other types of cells. HIV virus specifically attacks white blood cells.
Rhinovirus- common cold
Related to Viruses• Viroids - even smaller than
viruses, consist of RNA strands that lack a protein coat. Viroids mainly cause plant diseases.
• Prions - infectious agents that are believed to be the cause of Mad Cow Disease, relatively new find and much is not known about them. All diseases known to be of prion related, occur in animals
• Bacteriophage - viruses that infect bacteria.
This is your Brain
this is your Brain on Beef
Viral Replication • Viruses multiply,
or replicate using their own genetic material and the host cell's machinery to create more viruses.
• Viruses cannot reproduce on their own, and must infect a host cell in order to create more viruses.
Retroviruses• Retroviruses have RNA and the
enzyme reverse transcriptase instead of DNA as their nucleic acid core.
• Once inside the host cell, reverse transcription (making DNA from RNA) is accomplished by the reverse transcriptase, turning the single-stranded RNA into DNA.
• This new DNA is incorporated into the host DNA, where it transcribes new viral RNA genomes, as well as the RNA to synthesize new reverse transcriptase and protein capsules.
• The human immunodeficiency virus (HIV), a retrovirus associated with AIDS, replicates in this way.
Virus Replication Web Link
http://www.hivinfosource.org/animation.html
Protist• eukaryotes that
include unicellular and multicellular organisms
• Include autotrophic, heterotrophic, and parasitic organisms.
• contains the protozoa, algae, and fungus-like protist.
Where does the kingdom name "protista" come from?
• The Kingdom Protista was the third kingdom named. At the time, the other two kingdoms were for animals or plants. Some scientists wanted to include these organisms in the plant kingdom and others protested and wanted to place them in the animal kingdom. Eventually, a compromise was reached. They were all placed into a third kingdom, the Protists.
Protozoa (animal-like)• often microscopic (unicellular)
•Many relationships from - free living, parasitic, saprophytic, mutualistic •Cannot make their own food •Often classified by how they move
-Amoeba - moves with Pseudopods (false feet) -Paramecium - moves by cilia -Flagellates - move by the whipping flagella tails.-Sporozoans – moves by the fluid of the host they live inside of.
Amoeba
Paramecium
More Protozoans• Phylum Sarcodina
– Pseudopods (false feet) projections of cytoplasm.
– Some surrounded by a calcium "shell"
– Amoeba has no definite shape
– feed by phagocytosis--they flow around their prey (usually a smaller cell) and engulf it.
Amoeba
Ciliates • Phylum Ciliophora
– Moves using cilia - short hairs lining cell
– use cilia to sweep food down into their central channel or gullet.
• Other Ciliophora
– Stentor
– Vorticella
– Spinostomium
Paramecium
Stentor
Flagellates • Phylum Mastigophora
– Moves by long whip-like hairs.
– Often have more than one flagellum
– The organism which causes African sleeping sickness - carried by the testie fly
– Some live in the digestive tracts of termites and assist in the digestion of cellulose.
– No means of movement– can be transmitted through fluids
from one host to another. – Most sporozoan are spore-
forming parasitic (Harmful) protozoans.
• Plasmodium– Causes malaria, its life cycle
include stages in both the mosquito and humans
Algae (plant-like protist)• All algae contain
chlorophyll and carry out photosynthesis
• Vary in color and often named by its color.
• Most live in water, some on damp surfaces
• Make up a large part of the plankton of the oceans
Euglena• Phylum Euglenoids
– Most are unicellular
– Possess movement like animals
– Move by using whip like tail called flagellum (one only)
– Reproduces asexually
– Has eyespot to detect sunlight.
• Phylum Chrysophyta
– Two part shell of silicon (glass)
– Food stored as oil
– Responsible for most oil consumed today
– Forms the diatomaceous earth. These deposits are mined commercially as abrasives and filtering aids
Diatoms (golden algae)
Dinoflagellates (fire algae)• Phylum Pyrrophyta
– Surrounded with "plates"
– Has two flagella
– bioluminescent algae
– Responsible for "red tides"
– Contains toxins
Other algae or plant-like protist• Chlorophyta
– Green algae– Mostly freshwater– Multicellular (some unicellular– Seen as algae bloom in ponds
• Phaeophyta– Brown algae– Multicellular– Marine protist– Seaweed (giant kelp)
• Rhodophyta– Red algae (produces agar)– Multicellular– Marine protist
Green algae
Spirogyra
Brown algae (giant kelp)
Red algae
Fungus-like Protist• Slime Molds
– Live in moist soil and on decaying plants and trees
– Very colorful – blob of protoplasm– really nothing but a
large amoeba and feeds much the same way, by engulfing its food (mostly bacteria) with pseudopodia.
the dog vomit slime mold
FungiMycology - Study of fungi
• multicellular organisms, some unicellular(yeast)
• get their food through the absorption of organic nutrients
• Saprophytes - organisms that lives on dead organisms and decompose them
• Parasites - feed on living things• together with bacteria, they
allow the recycling of dead organisms into the environment
• mushrooms, molds and yeast are common examples of fungi.
Basic Fungus Groups• Zygomycota
– Common molds
• Ascomycota– Sac fungi
• Basidiomycota– Club fungi
• Deuteromycota– Imperfect fungi
• Oomycota– Water molds
Zygomycota• Common Molds
– Black bread mold– filamentous fungi which
are terrestrial growing on moist, dead organic matter.
– body is called a mycelium; it is made up of interwoven, thread-like structures called hyphae.
– Reproduces both asexually and sexually.
Bread mold
Common Mold
Ascomycota
• Sac Fungi– yeast (unicellular)
– cup fungi
– morals
– truffles
– most reproduces sexually, yeast reproduce asexually by budding
cup fungi
moralsyeast
Basidiomycota
• Club Fungi– Mushrooms
– puffballs,
– Bracket fungi
– Wheat rusts
– Reproduces mostly sexually.
Amanita Fly (poisonous)
puffballs
bracket fungi
Deuteromycota
• Imperfect Fungi– Penicillium
– Aspergillus
– Ringworm
– Athlete’s foot fungus
– reproduces asexully only(this is why it is called imperfect)
Ringworm
Athlete’s foot fungus
Oomycota
• Water molds– Downy mildew
– Potato blight fungus
– Reproduces both sexually and asexually.
Common water mold
Potato blight fungus
Fungus Economic Importance
– yeast is used widely by brewers and bakers to prepare alcohol and in raising bread.
– some mushrooms are used as food for their delicacy and high nutritive value.
– the fungus Penicillium is used for the production of antibiotic penicillin.
– few species are used to give flavor and texture to cheese.
Fungus Ecological Significance
– If it was not for the actions of decomposers, nutrients would get locked up in the dead matter of organisms.
– Life on earth without these organisms eventually would become impossible.
Lichens– It is an association between
an alga and a fungus, which together form a closely integrated unit.
– The body of a lichen is composed of branching hyphae of a fungus, which harbor algal cells.
– The fungus gets food by the alga and the alga in
return gets shelter, moisture and minerals absorbed by the fungal partner.
- Found on rocks, tree trunks and walls
Lichens Economic Importance
– Some lichens are valuable source of food to wild animals like reindeer.
– Some lichens are fried and given to cattle as food and to some extent to human beings.
– Some are used in medicines and other are for preparation of dyes.
– Litmus is prepared from certain lichens and some are also used in the preparations of cosmetics and perfumes.
Lichens Ecological Significance
– Lichens growing on rocks disintegrate them to form soil, preparing the ground for mosses and subsequently for higher plants. Thus, they help in the succession of plant communities.
