Biology 1002

Taxonomy
Branch of Biology that is concerned with naming classifying organisms
Carolus Linnaeus
Modern taxonomy. Introduced the two part scientific name (Scientific bi nomenclature)
Two Part scientific name
Genus species
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Genus
a group that includes a number of very closely related species
Species
a genus that includes populations of organisms that can potentially interbreed naturally
Linnaean Classification System
Eight taxonomic categories
Name the Linnaean Classifications
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Modern Classification
emphasizes patterns of evolutionary descent as biologists realized that taxonomic categories should reflect evolutionary relatedness
The more ____ two organisms share the closer their __ relationship
The more categories two organisms share the closer their evolutionary relationship
When humans evolved from apes T/F
We have a common ancestor, T
Phylogeny
Modern classification. Reconstructs evolutionary history.
Systematics
Science of reconstructing phylogeny or evolutionary history.
What do systematists identify to show evolutionary relationships?
Features; genetic, characteristics, appearance
What defines life? *Function is the same.
What plays a key role in systematists?
Anatomy
How does anatomy play a key role in systematists?
They look at external and internal structures help identify evolutionary history
Homologous Structures
Same structures and functions, common ancestor, split into different species
Molecular Similarities
Systematists examine genetic similarities between DNA nucleotide sequences
How common is chimp DNA nucleotide sequence to humans?
96%
Similarities in ____ can also be used to establish relationships between organisms
chromosome structure
Before 1970, how were species divided?
Anamalia and Plantae (including plants, bacteria, fungi, and photosynthetic eukaryotes)
Why was the two-domain approach an oversimplification?
It didn’t accurately reflect life’s history
Describe the solution of the two domain system and who came to discover it
The solution: Three domain system. Carl Woese discovered that prokaryotic organisms included two very distinct groups (Bacteria and Archaea)
Prokaryotic Characteristics
No nucleus or nuclear envelope
Genetic material in a nucleoid region
No organelles or internal membrane
Eukaryotic Characteristics`
Nucleus with an envelope
Genetic material in the nucleus
Contains cytoplasm with membrane bound organelles
Current three domain system
Bacteria (p)
Archaea (p)
Eukarya (e)
Animals
Protists
Fungi
Plants
When did the three domains split?
They split very early in life, long before animals and plants evolved
How many kingdoms are in the domain Eukarya?
Four: Animalia, Plantae, Fungi, and Protists
When/How do classifications change?
They change when new info is discovered. They are frequent changes at the species level. Rarely are there changes in the domain and kingdom level.
Ex: African (Savannah and Forest) and Indian Elephant
Biodiversity
Total number of species in an ecosystem
Currently: 1.5 million most are animals. there is believed to be a high multitude of prokaryotes and protists that aren’t discovered yet
How many species exist?
7-10 million
7,000-10,000 are identified/yr
Where is the home to two thirds of the world’s existing species, most of which have yet to be named?
Tropical Rainforests
What was the purpose of the recently completed Human Genome Project?
to determine the nucleotide sequence in human DNA
In the five-kingdom system, prokaryotes are placed in the kingdom _____.
Monera
In the two-kingdom system, why were fungi classified in the kingdom Plantae?
They are sedentary
When did the “tree of life” split into three parts, Bacteria, Archaea, and Eukarya
before the appearance of plants, animals, and fungi
From a classification viewpoint, how are plants associated with animals?
They both belong in the Domain Eukarya.
Why is it particularly difficult for the systematist to classify asexually reproducing organisms as a species?
Asexually reproducing organisms do not interbreed.
HIV-1 has not always been found in humans, where could it have originated?
in non-human primates
How can an understanding of the evolutionary origin of HIV help researchers devise better ways to treat and control the spread of AIDS?
It may be possible to use an animal model, such as the chimpanzee, to study treatment and spread of the disease.
What were Earth’s first organisms?
Prokaryotes, single celled microbes that lacked organelles
What forms 2/3 of life’s domains?
Bacteria and Archaea (P)
What are Bacteria and Archaea’s similarities?
They are both prokaryotic, single celled organisms.
What are the structural differences between Bacteria and Archaea?
They have different cell walls, plasma membrane composition, ribosomes, and RNA polymerases. There is also differences in transcription and translation processes.
What is a polysaccharide that strengthens the cell wall of bacteria and is not found in Archaea?
Peptidoglyan
Prokaryotic Classification
Shape, Means of Locomotion, Pigments, Nutrient requirements, colony appearance, gram staining characteristics, and nucleotide sequences.
Prokaryotic Shape and Structure
They differ. Some are extremely small. They have three different shapes: spherical, rod like, and corkscrew.
Prokaryotic Locomotion
Flagella: singly in pairs or scattered over the cell surface.
Bacteria Flagella
Wheel and Axle: within cell wall and plasma membrane, rapid rotation.
Archael flagella
Thinner and constructed from proteins
Bacteria forms ___ on surfaces
Film, of carb/ protein slime
Biofilms
Slime secreting bacteria, ex dental plague.
Bacteria embedded in biofilms…
Protected from disenfectants and antibiotics. ex- plague physically removed.
Bacterial Endospores
Protective endospores allow some bacteria to withstand adverse conditions. they are thickly wrapped particles of genetic material and few enzymes.
What can endospores endure?
Boiling for an hour, being sealed within a rock for 250 million years.
Practically, harsh conditions
What are prokaryotes’ environment?
High pressure, cold, high salt, acidic, alkaline, moderate, and hot
Describe prokaryotic metabolism
Anaerobic/aerobic
Give an example of aerobic/anaerobic
Both: E Coli
Anaerobic: Tetanus
How do prokaryotes extract energy?
organic compounds like carbs, fats, and proteins
poisonous compounds to humans like methane, petroleum, benzene
inorganic molecules, like hydrogen, sulfur, ammonia, and iron
sunlight- cyanobacteria
How do they reproduce (Pro)?
binary fission, occuring as fast as 20 minutes, and causes rapid spreading mutations and rapid evolution
What is conjugation?
It is the exchange of genetic materials without reproduction, utilizing sex pili. It can ever occur with different species
How does conjugation occur?
Circular DNA molecules called plasmids carry genes to the donor, through the sex pili (connect a cytoplasmic bridge)
How are the plasmids resistant to antibiotics?
They contains alleles conferring mutations or evolutionary resistance
Can conjugations produce new genetic combinations?
Yes
How are prokaryotes beneficial?
They play important roles in animal nutrition, human nutrition, recyclers, and clean up pollution.
How do prokaryotes play a role in animal/human nutrition?
Herbivores depend on them to break down cellulose in the cell walls of plants, many foods are produced by bacterial action, and they produce vitamins (vitamin K and b12)
How do prokaryotes recycle?
CATABOLISM. They obtain energy from breaking waste products and the dead bodies of plants and animals into simpler molecules, which provides the basis for continued life on Earth.
How do prokaryotes clean up pollution?
Nearly all human made susbstances are biodegradable by some sort of bacterial species, specifically oil in the case of the Exxon Valdez clean up.
How are prokaryotes harmful for health?
Disease producing (pathogenic), anaerobic bacteria (poisons), common bacterial species can be harmful
Do pathogenic archaea exist?
No, they have yet to be discovered.
Name harmful anaerobic bacteria
Clostridium tentani: tetanis
How does clostridium tentani work?
It enters through the body through a puncture wound and if its lodged deeply enough, it produces a paralyzing poison (lockjaw)
What can pathogenic bacteria cause?
Bubonic plague, Staph, Meningitis, food poisoning, STDs, tuberculosis, and others
Describe Bubonic plague
It is spread by rat fleas, and killed 100 million people in the 1300s, a third of the population
Tuberculosis
caused by Pathogenic bacteria.
Ghonorrhea and syphilis
STDs caused by pathogenic bacteria
Cholera
Caused by pathogenic bacteria. It is water transmitted.
Name harmful common bacterial species
Strep and E Coli
Describe Strep
Caused by bacteria, and includes tooth decay, pneumonia, and flesh eating infection
Describe E Coli
Caused by bacteria. It commonly inhabits the digestive system. Some are pathogenic. It is transmitted through infected cattle/ undercooked.
Define a virus
It consists of a molecule of DNA or RNA surrounded by a protein cote. They have no cells. They need a host to reproduce. Small. Variety of shapes.
Is a virus, viroid, or prion considered to be living?
NO
Name different virus (diff shapes)
Rabies virus, bacteriophage, tobacco mosaic virus, and influenza
Whats the function of the virus protein coat?
It enables entry into a host cell
How does our immune system respond to viruses?
Destroys it immediately. When you get sick, its the virus your immune system wasn’t able to destroy.
T/F: Each viral type is specialized to attack specific host cells, and is only capable of invading the host cells it is specific for
True. For example, bacteria are infected by bacteriophage viruses. A good virus attacks a bacteria. HIV binds with cell receptors.
Describe bacteriophages
They are a type of virus, specified to attack bacteria. It can be used to treat bacterial diseases. (Hand santitizer). However, it makes it less effective.
Describe the specified virus types that attack human cells
Cold (Respiratory), rabies (Nerve), herpes ( Genitals, mouth)
HIV (Human Deficiency Syndrome)
It is virus, which attacks a specific white blood cell type. It causes AIDS
Cervical Cancer
10% of women. HPV remains in the cells of the cervix and increases the chance of cancer.
HPV
90-98% causes cervical cancers. Factors also increase the risk of cervical cancer: age, smoking, and lowered immunity.
Vaccine: gardasil, not a cure.
Hep B and C
Cause liver infections, viral infections. It is spread through unprotected sexual contact or exchange of blood.
Why do viruses have high mutation rates?
They lack the mechanisms to correct errors. They cause resistance to an antiviral drug, and these render drugs ineffective.
Define a viroid
They are some infectious agents that are even simpler than viruses. They are simple infectious particles with short RNA strands. They enter a host cell nucleus and direct new viroid synthesis.
Define a prion
It is a misfolded, infected protein.
Kuru
Prion. Degenerative disease in New Guinea. Transmitted by ritual cannibalism of the dead, affected the nervous system
Other degenerative diseases (Prions)
Kuru, CJD, Scrapie, Mad Cow/ BSE, etc.
Stanley Prusiner
1982, demonstrated that diseases were caused by an infectious protein particle devoid of any nucleic acids. They are heritable and transmitted.
How are prions inherited?
Point mutations, may be linked to Alzheimers and Parkinsons
How are prions destroyed?
Clorox Bleach. Normal proteins would unfold and denature. Nothing else works, they are trying to find stem cell research for replacing the dead neurons.
How much does bacteria replicate in one hour?
Binary Fission, 20 mins/ 6x
What are protists?
any eukaryote that is not a plant, animal, or fungus. Most protists are microscopic in size
Some are large aggregations or colonies of single-celled individuals; others are multicellular organisms
How do protists obtain nutrition?
Ingestion, Absorption, and Photosynthesis
Protists (Ingestion)
Predators, using the extensions of the cell membrane called psuedopods to surround and engulf prey.
Protists (Absorb)
They absorb directly from the environment. They have two types, either free living types in the soil that decompose organic matter or parasites that live inside the bodies of a host organism.
Photosynthetic protists
Oceans, lakes, ponds. ALGAE
What is algae?
ALL photosynthethic protists
What are protozoa?
Non photosynthethic protists
How do protists reproduce?
Asexually: Mitotic cell division
Sexually: genetically diverse
How do protists affect humans/ organisms?
The ecological role of algae is positive; they capture solar energy and make it available to other organisms in the ecosystem, and also release oxygen gas into the water, allowing fish to breathe
What are protists’ negative impact?
They cause deadly diseases, destroy crops, and release toxins that can accumulate to harmful levels in coastal areas
What are the major groups of protozoans?
Excavates, Euglenozoans, Stramenopiles, Alveolates, Rhizarians, Amoebozoans. Red and Green Algae..
Define Excavates
They are protozoan group. They have a feeding groove and lack mitochondria.
Giardia
Excavate: gastrointestinal diseases
Euglenozoans
Distinctive mitchondria. Live mostly in freshwater and swim with a flagella.
Euglena
Euglenozoan. Contains a photoreceptor that detects the direction of light and allows the organism to move towards light to perform photosynthesis.
Stramenopiles
Includes photo and non photosynthetic organisms. All have thin, hair like flagella. Can be unicellular or multicellular. Includes mold, diatoms, and brown algae
Alveolates
Parasites, predators, and phytoplankton. Single celled. Can caused red tide/malaria.
Rhizarians
foraminiferans and radiolarians. Pseudopods are think and threadlike +shells. Foraminiferans: chalky shells. Radiolarians: shells, silica.
Amoebozoans
Inhabit aquatic and terrestrial environments, feed and move by pseudopods. Predatory/ Parasitic. Some causes dysentery.
Red Algae
Clear tropical oceans. Multicellular, photosynthetic seaweeds. Pigments range from red to black, where they absorb the deeply penetrating blue green light and transfer this light energy to chlorophyll.
Green Algae
Ponds and lakes, photosynthetic, multicellular and unicellular.
Whats the process of alternations of generations?
A diploid generation alternates with a haploid generations
Sporophyte
A diploid sporophyte plant produces haploid spores through meiosis
Gemetophyte
After the sporophyte plant produces haploid spores by meiosis, mitosis occurs. The spores divide into haploid gametophyte plants.
End result of alternation of generation
Haploid gametophyes produces haploid male and female gametes through mitosis. the gametes fuse and form diploid zygotes
How do plants play a crucial ecological role?
Plants capture energy that other organisms use, through photosynthesis, plans build soil, prevent erosion and flooding, plants help keep ecosystems moist and help maintain the atmosphere by the release of oxygen.
Where do plants originate from?
green algae, called stonewarts. They have similar DNA and use the same type of chlorophyll and accessory pigments in photosynthesis. BOth use starch and have cellulose in cell walls.
Did land help plants?
It gave them direct access to sunlight, access to nutrient rich soil

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