Biology Basics and Evolution

flashcards covering taxonomy, domains, bacteria, protists, and plant evolution from the provided video notes.

What is speciation?

The process by which new species arise through genetic changes over time.

What does evolution mean in biology?

Genetic change in a population over time.

What is microevolution?

Small genetic changes within a population over time.

What is macroevolution?

Large-scale evolutionary changes over long time periods.

What is taxonomy?

The science of classifying organisms.

What did Linnaeus contribute to biology?

Developed an early system to organize living things in the 1700s and published on classification.

How many organizational levels did Linnaeus use, and how many are used today?

Seven originally; eight now.

Approximately how many species are estimated to exist on Earth?

7–10 million.

Who is the main cause of extinction on the planet?

Humans.

What is the purpose of taxonomic classification when you find a new organism?

To classify and name the organism.

What does the Greek word 'tax' mean?

Arrangement.

List the eight taxonomic ranks from highest to lowest.

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

What does 'hierarchy' mean in taxonomy?

From the most general to the least general.

Which is the largest taxonomic category?

Domain.

What is a Kingdom in taxonomy?

A grouping where organisms are more closely related within higher levels.

What is a Phylum in taxonomy?

A major category within a kingdom.

What is binomial nomenclature?

The two-name system using genus and species.

How should genus and species names be formatted?

Genus capitalized, species lowercase; italicized or underlined.

What is Felis catus?

The binomial name for the domestic cat.

What is Canis familiaris?

The binomial name for the domestic dog.

What is Domain in the three-domain system?

Largest group based on cellular characteristics.

Name the three domains.

Bacteria, Archaea, Eukarya.

Are bacteria prokaryotic or eukaryotic?

Prokaryotic.

Where is the bacterial chromosome located?

In the nucleoid (not a true nucleus).

What are plasmids?

Additional circular DNA molecules in bacteria.

What cellular features do bacteria have?

Cell membrane, ribosomes, circular chromosome, plasmids, and often an outer cell wall with peptidoglycan; some have flagella.

What are the main bacterial shapes?

Rod-shaped (bacillus), spherical (coccus), spiral-shaped (spirillum).

How do bacteria arrange in clusters?

Staphylococcus forms grape-like clusters.

How do bacteria arrange in chains?

Streptococcus forms a chain.

Gram-positive bacteria color in Gram staining?

Purple (thick cell wall).

Gram-negative bacteria color in Gram staining?

Pink (thin cell wall).

What energy sources do bacteria use?

Autotrophs and heterotrophs.

What is a photoautotroph? Provide an example.

Uses light energy; example: cyanobacteria.

What is a chemoautotroph? Energy source?

Uses chemicals as energy; electrons from minerals such as iron.

What is a heterotroph?

Obtains nutrition from outside sources; includes decomposers and saprotrophs.

What is an autotroph?

An organism that makes its own food.

What is an aerobe?

Requires oxygen.

What is an anaerobe?

Does not require oxygen.

How do bacteria reproduce?

Binary fission; chromosome duplicates and divides; vertical gene transfer.

What is transformation in bacteria?

Bacteria incorporate DNA from a dead bacterium.

What is conjugation?

DNA exchange between bacteria via a conjugation tube.

What is transduction?

DNA transfer via a bacteriophage.

Where can symbiotic bacteria be found?

In nodules of legumes, helping plants acquire nitrogen.

What is a pathogen?

Bacteria that cause disease.

How can pathogens cause disease?

By producing toxins and by adhering to surfaces and invading tissues.

How do antibiotics work?

Rupture cell walls, interfere with metabolism, or destroy enzymes.

Name some bacterial STIs.

Chlamydia, gonorrhea, syphilis; pelvic inflammatory disease.

What is antibiotic resistance?

Bacteria that have evolved to be resistant to antibiotics because of their exposure to them over time (aka ‘super bugs’)

What are 'superbugs'?

Antibiotic-resistant bacteria.

What are causes of antibiotic resistance?

Overuse of antibiotics, use in agriculture, and mutations.

What are halophiles?

Archaea that require high salt concentrations.

What is an endospore?

A durable dormant form allowing survival in harsh environments.

Examples of endospores surviving long periods?

Anthrax spores and botulism bacteria.

What ecological roles do bacteria play?

Decomposers; recycle nutrients; degrade pollutants (bioremediation).

Name some products produced by bacteria.

Alcohol, cheese, yogurt, vitamins, antibiotics; biotechnology.

Which domain is ancestral to Eukarya?

Archaea.

What are archaea commonly known for?

Extremophiles; survive extreme conditions.

What allows archaeal membranes to function at high temperatures?

Unusual lipids in their membranes.

How are archaea classified?

By habitat.

Name two archaeal groups.

Methanogens, Halophiles, and Thermoacidophiles.

What is the Endosymbiotic Theory?

Explains the origin of eukaryotic cells, a eukaryotic cell arose when a host cell engulfed a smaller bacteria that became organelles.

What are Protists?

Organisms not fitting into Fungi, Plants, or Animals; mostly unicellular.

What criterion defines multicellularity for plants, animals, or fungi?

They must be multicellular.

How many groups are Protists organized into and what are they?

Plant-like (algae), animal-like (protozoans), fungus-like (slime molds and water molds).

What are Algae?

Plant-like protists that are autotrophs.

How are algae classified?

By pigment type and other features like chloroplasts and reproduction.

What pigment type characterizes Green Algae?

Chlorophylls a and b; starch and cellulose.

Name examples of Green Algae.

Chlamydomonas, Volvox, Spirogyra, Ulva.

What are Brown Algae and their features?

Temperate marine; chlorophylls a & c; fucoxanthin; holdfast; seaweeds; source of algin.

What is a holdfast?

Anchoring structure for brown algae.

Name examples of Brown Algae.

Fucus, Sargassum, Macrocystis.

What are Golden Algae?

Diatoms; aquatic; silica cell walls; major producers of atmospheric oxygen.

What is Diatoms' significance?

They contribute to a large portion of atmospheric oxygen; diatomaceous earth is used as abrasive.

What are Dinoflagellates?

Marine protists with two flagella; some cause red tides; important food source.

What are Red Algae?

Marine algae with phycobilin (light absorbing) pigments; can live in deeper waters; source of agar and carrageenan (both gel-like thickeners).

What are Euglenoids?

Have a flagellum and an eyespot; no cell wall; contain chlorophyll.

What are Protozoans?

Animal-like protists; unicellular and heterotrophic; aquatic plankton; some pathogens.

How can Protozoans move?

By Cilia, Flagella, or Pseudopods.

What are Amoeboids?

Pseudopods; contractile vacuoles; examples include Amoeba proteus and Entamoeba histolytica.

What are Foraminiferans and Radiolarians?

Foraminiferans have CaCO3 skeletons; Radiolarians have silica skeletons.

What are Ciliates?

Move with cilia; contractile vacuoles; have macro- and micro-nuclei.

What are Zooflagellates?

Move with long flagella; may be free-living or pathogenic; example Trypanosoma brucei.

What is Trypanosoma brucei?

Parasite causing African sleeping sickness; vector: tsetse fly.

What is Trichonympha?

Lives in termite gut; helps digest cellulose.

What are Giardia lamblia and Trichomonas vaginalis?

Giardia causes traveler's diarrhea; Trichomonas causes trichomoniasis.

What are Sporozoans?

Non-motile parasites that form spores; examples: Plasmodium vivax, Cryptosporidium.

What is the malaria vector?

Female Anopheles mosquito.

What are Water Molds?

Fungus-like protists; aquatic; saprotrophic; cause ick and potato blight.

What are Slime Molds?

Fungus-like protists; heterotrophic; plasmodial stage; cytoplasmic streaming; spore production.

What are the five events that helped land plants adapt to life on land?

Cuticle, vascular tissue, nourishment of multicellular embryo within female plant, seeds, flowers.

What is the function of a plant cuticle?

Water-conserving waxy coating on leaves.

What is the function of vascular tissue in plants?

Moves water, nutrients, and carbohydrates throughout the plant.

Why is nourishment of the multicellular embryo important?

Embryo develops within the female plant and is protected.

What is the significance of seeds in plant evolution?

Seed development enables dispersal and dormancy.

What is the significance of flowers in plants?

Reproductive structures enabling pollination and diversification.

What is alternation of generations?

Two plant forms: sporophyte (diploid) and gametophyte (haploid).

What is a sporophyte?

Diploid, spore-producing generation.

What is a gametophyte?

Haploid, gamete-producing generation.

How are spores produced in plants?

Meiosis produces haploid spores; spores grow by mitosis into the gametophyte.

Which generation is dominant in nonvascular plants?

Gametophyte.