knowt.exam 1 bio

Taxonomy

The science of classifying organisms.

Three Domains

Bacteria, Archaea, Eukarya.

Linnaeus

Developed the first classification system.

Organizational Levels

Eight levels from least inclusive to most inclusive: species, genus, family, order, class, phylum, kingdom, domain.

Binomial Nomenclature

Scientific name given to each species; for example, Humans: Genus= Homo, Species= Sapiens.

Classification Criteria

Anatomy, embryological development, habitat, energy source, reproduction, biochemistry.

Microevolution

Changes on a small scale at the level of gene pools alleles.

Macroevolution

Evolution at a large scale as species originate, adapt to their environment, and possibly become extinct.

Speciation

Gives rise to new species when members of the population can no longer interbreed.

Biological Species Concept

A group of organisms that interbreed and share the same gene pool, producing fertile offspring.

Allopatric Speciation

Speciation that occurs when populations have no contact.

Sympatric Speciation

Speciation that occurs when populations live in continuous contact.

Pre-mating Reproductive Barriers

Include habitat isolation, temporal isolation, behavioral isolation, mechanical isolation, gametic isolation.

Post-mating Reproductive Barriers

Include hybrid inviability and hybrid sterility.

Habitat Isolation

Occurs when organisms cannot reproduce because they live in different habitats.

Temporal Isolation

Occurs if the reproduction of organisms happens at different times.

Behavioral Isolation

Occurs when organisms display unique courtship patterns.

Mechanical Isolation

Occurs if animal genitalia or plant floral structures are incompatible.

Gametic Isolation

Occurs when sperm cannot fertilize the egg due to matching surface proteins.

Hybrid Inviability

Two species mate but exhibit early death or non-viable embryos.

Hybrid Sterility

Two species mate but produce sterile offspring.

Domain Bacteria

Prokaryotic, smallest of all living organisms, most biologically successful.

Cyanobacteria

Also known as blue-green algae.

Bacteria Structure

Prokaryotic; includes cell wall (peptidoglycan), nucleoid, plasmids, flagella, ribosomes.

Coccus

Spherical shaped bacteria.

Bacillus

Rod shaped bacteria.

Spirillum

Spiral shaped bacteria.

Strepto

Cellular arrangement forming a chain.

Staphylo

Cellular arrangement forming a cluster.

Gram Positive

Bacteria with thick peptidoglycan layer.

Gram Negative

Bacteria with thin peptidoglycan layer.

Autotrophs

Organisms that are "self-feeders."

Photoautotrophs

Organisms that use sunlight as an energy source.

Chemoautotrophs

Organisms that use chemicals as their energy source.

Heterotrophs

Organisms that are "other feeders."

Aerobes

Bacteria that require oxygen to grow.

Anaerobes

Bacteria that do not require oxygen to grow.

Decomposers

Organisms that recycle nutrients and degrade pollutants.

Economic Importance of Bacteria

Used in alcoholic beverages, cheese, vitamins, antibiotics, and yogurt.

Horizontal Gene Transfer

Includes conjugation, transformation, and transduction.

Conjugation

A method of sexual recombination where genetic material is exchanged between bacteria.

Transformation

When bacteria incorporate DNA from a dead bacterium.

Transduction

Occurs when a bacteriophage carries DNA from one bacteria cell to another.

Vertical Gene Transfer

DNA passes from one generation to the next through binary fission.

Antibiotics

Substances that rupture bacterial cell walls and interfere with bacterial metabolism.

Antibiotic Resistance

Bacteria that are resistant to antibiotics due to overuse and mutations.

Bacterial STD/STI

Includes chlamydia, gonorrhea, syphilis.

Nitrogen-Fixing

The process in which prokaryotes convert atmospheric nitrogen into absorbable forms.

Domain Archaea

Organisms with cellular modifications that allow survival in extreme conditions.

Non-pathogenic

Bacteria that are not harmful.

Halophiles

Archaea that require high salt concentrations for growth.

Thermoacidophiles

Archaea that live in hot acidic environments.

Methanogens

Methane-synthesizing Archaea found in anaerobic environments.

Endosymbiotic Theory

Suggests that early eukaryotes obtained mitochondria and chloroplasts by engulfing bacterial cells.

Protista Structure

Eukaryotic, unicellular, filamentous, colonial, can be autotrophic or heterotrophic.

Algae

"Plant-like" organisms containing different photosynthetic pigments.

Green Algae

Ancestors of plants, containing chlorophyll a and b.

Unicellular

Made of a single cell.

Filamentous

Thread-like bacteria.

Multicellular

Made of many cells.

Sexual Reproduction in Protista

Performed through conjugation.

Asexual Reproduction in Protista

Includes transformation and transduction.

Symbiotic Relationship with Fungi

Lichen.

Symbiotic Relationship with Animals

Coral.

Brown Algae

Seaweeds, source of algin, and iodine.

Golden Algae

Diatoms, source of oxygen and silica.

Red Algae

Source of agar and carrageenan, known to live at greater depths.

Dinoflagellates

Characterized by two flagella, associated with red tide.

Euglenoids

Most animal-like protists with flagella and eyespot.

Protozoans

"Animal-like" organisms classified by movement.

Amoeboids

Class of protozoans including amoeba, foraminiferans, radiolarians.

Pseudopods

"False feet" used by amoeboids for movement.

Contractile Vacuoles

Membranous sacs that move excess water out of the cell.

Amoeba

Single-celled organisms in kingdom Protista that can move by themselves.

Phagocytosis

The process of a cell eating.

Foraminiferans

Protozoans with skeletons of calcium carbonate.

Radiolarians

Amoeboids with cell walls made of silica.

Ciliates

Protozoans with cilia for movement.

Paramecium

Free-living, motile ciliate.

Cilia

Hairlike projections used for movement in protozoans.

Zooflagellates

Flagellates including Trypanosoma, Trichonympha, Giardia, Trichomonas.

Trypanosoma

Causes African sleeping sickness.

Trichonympha

Symbiotic in termites.

Giardia

A human pathogen.

Sporozoans

Parasitic protozoans such as Plasmodium vivax and Cryptosporidium.

Plasmodium vivax

Causes malaria.

Cryptosporidium

A parasitic organism.

Slime Molds

"Fungi-like" organisms that are heterotrophic and spore-producing.

Water Molds

"Fungi-like" organisms that live in water and are saprotrophic decomposers.