Bio 80 Exam 1

Briefly describe 5-6 of the characteristics of life.

• All cells use DNA to produce mRNA molecules which orders the production of polypeptides that are modified into proteins

• Share common chemical composition in that they consist of organic molecules (have carbon bonded to carbon, contain proteins, lipids, carbohydrates, and nuclei acids), mostly made of water, and run off of ATP

• Cells are the basic units of life (single celled/unicellular organisms, multicellular organisms)

• Convert energy and matter in complex enzyme-driven pathways (**EVERYTHING obtains and converts energy, NOTHING destroys energy)

• Living things are highly organized; matter made up of subatomic particles (protons, neutrons, electrons) — subatomic particles<atoms<molecules<organelle<cells<tissue<organs<individual organisms<populations/colonies<community<ecosystems<biosphere

• Living things grow and develop in specific predictable patterns

• Organisms reproduce (completely/partially)

• Living things maintain relatively constant internal conditions – homeostasis (temp, mass, water, salt, nutrients)

• All organisms, as populations, change genetically over time (mutations/evolution)

• Living things are dependent on each other and their non-living environment (ex: bacteria in soil & nitrogen cycle)

Autotrophs vs Heterotophs

Autotrophs (producers) manufacture their own food while heterotrophs (consumers) feed on other organisms (ex: plants vs decomposers)

Asexual vs Sexual Reproduction

Asexual — only one parent, offspring genetically identical, can have duplication error, successful strategy in unchanging environments, complete reproduction (ex: bacteria, cactus); Sexual — two parents, offspring genetically different, partial reproduction, successful in changing environment

Homeostasis

Organisms maintain an optimal balance on temp, mass, nutrients, salt, water, etc.

Mutation

Alterations to DNA programming

Evolution

Changes in gene frequencies in populations over time

Scientific method

• Empirical observations

• Hypothesis formation

• Experimentation

• Conclusions

• Publication

• More testing

• Theory building

Meaning and purpose of a “control”

Experimental feature used to account for effects of nonexperimental variables

Experiment

A set of controlled experiences used to test a hypothesis

Empirical

Relating to the sense

Variable

Unstable or changeable factors that can influence an outcome

Senses that human beings possess (at least 6)

• Vestibular 1 - linear

• Vestibular 2 - rotational

• Balance

• Tensile (weight) 1

• Tensile (weight) 2

• Propioception

• Thermal (hotter/cooler)

• Pressure

• Humidity

• Magnetic

Hypothesis

An idea that can be scientifically tested

Theory

A set of statements based on tested scientific facts that acts to describe, explain, or predict aspects of a given phenomenon

Probability

The numerical calculation of the extent to which an event is likely to occur or the extent to which a given proposition is likely to be true; NOT absolute certainty, any scientific finding is subject to being rejected in the future based on further testing

Continual testing vs Final Proof

Evaluating project throughout the entire development lifecycle vs singular decision review conducted before final release

Formation of the Universe

13.8 bya

Formation of th Earth

4.5 bya

Earth begins to cool

3.6 bya

Life definitely recorded around

3.5 bya

Multicellular forms show up

2-1.6 bya

Animals show up at about

600-500 mya

Plants show up

550 mya

Colonization of land by fungus and plants

450-500 mya

Colonization of land by animals

450 mya

Human beings in their modern form

250-200 tya

Isotope

Atoms of the same element that have a different number of neutrons

Half-life

Time needed for half of a radioactive isotope to decay to a stable isotope

Potassium-Argon Radiometric Dating

dating igneous volcanic rocks ~100 tyo-byo

Uranium-Lead Radiometric Dating

Measuring the amount of lead-206 daughter isotopes in a sample, determine age of igneous rocks ~100 myo-4 byo

Carbon-14 Radiometric Dating

Dating organic matter (woods, bones, shells, other ogranismic remains), constant ratio of C-14 and C-12, C-14 undergoes radioactive decay and C-12 doesn’t, organisms lived in last 45,000 years

Ribozyme

an RNA molecule capable of acting as an enzyme, joins with amino acids to form polypeptides, typically no ability to self replicate

Radioactivity

Emission of sub-atomic particles from unstable atomic nuclei

Oparin-Haldane Hypothesis

Chemicals in the early Earth atmosphere were fueled by sunlight and could have spontaneously created small organic molecules that would’ve infiltrated the early sea

Urey-Miller Experiments

Tested the Oparin-Haldane hypothesis with lightning, filled glass flask with water + heated for water vapor (sea/atmosphere), added methane and ammonia vapor to second flask (early atmosphere), sparks was energy source, below second flask water vapor cooled and recycled (rain and sea), all experiments produced complex organic molecules

Where on Earth modern researchers think life began

Deep-sea alkaline vents/Abyssal hot springs

Which type of molecule is thought to be OG genetic material and why

RNA — simpler than DNA, ahs catalytic properties, ribozyme ; would’ve been produced spontaneously partially/completely, replicated faster w/ less errors, copying errors introduce mutations (successful molecules produced)

Symbiogenesis (endosymbiosis)

Merging of two separate organisms to form a single new organism; eukaryotes arise by symbiogenesis, merging increases survival changes of each genome from bacteria that eventually transformed into mitochondria and chloroplasts

Diploid

Containing 2 sets of DNA molecules, one set from each parent (having 2 members of each homologous DNA molecule pair)

Haploid

Containing 1 set of DNA molecules (having 1 member of each homologous DNA molecule pair)

Monad

DNA molecule in unreplicated state

Dyad

DNA molecule in duplicated state

Tetrad

Cluster of four sister chromatids in meiosis

Homologous pair

DNA molecules of the same shape, size, and code for the same polypeptides at the same sites (loci)

Mitosis

Eukaryotic process where cell’s DNA is duplicated and duplicates separate into two new, identical cells (Interphase, Prophase, Prometaphase, Metaphase, ANaphase, Telophase, Cytokinesis)

Meiosis

Eukaryotic process the produces haploid cells (gametes -- egg/sperm) from diploid cells

Transcription

Nucleus of eukaryotic cells, occurs first, produces mRNA, RNA polymerase used exclusively to build mRNA strand from DNA template

Translation

Cytoplasm on ribosome, happens second to transcription, cells read mRNA to build protein & produces polypeptide, used exclusively to read mRNA and link amino acids together

Gene

A sequence of DNA molecules that encodes for a specific polypeptide or mRNA sequence

Four functions of mitosis

• One organism grows from one to many cells

• Allows for the repair of damaged tissue (NOT repair of damaged cells!)

• Replenishment of cell types that die

• Complete reproduction of single-celled eukaryotes

3 sources of genetic variation within/from meiotic process

Crossing over in prophase 1 to create new genetic combination on chromosomes, random alignment creating new combinations of maternal/paternal chromosomes in gametes at metaphase 1, syngamy; the fusion of gametes to create a zygote creates new genetic combinations in organisms (recombination)

3 basic shapes of the bacteria

Cocci, bacilli, spirals (spirochetes, spirilla, vibrios)

Capsules

Disorganized sticky layer made of short-chain polysaccharides, used for adherence to hosts and other substrates, anti-desiccation, resist viruses

Fimbriae

Used to fasten bacteria to substrates

Pili

Fasten bacteria to other bacteria

Flagellum

Whip-like motility device

Plasmids

Small rings of original DNA, only few genes on them, may code for specific structural proteins

Endospores

Desiccated packages of bacterial DNA and ribosomes surrounded by protein coat, resist heat, radiation, and further desiccation

Cell wall

Made of peptidoglycan (carbohydrate/protein polymer)

Cytoplasm

Semi-fluid material inside the cell between plasma membrane and nuclear envelope in eukaryotic cells

Plasma Membrane

Flexible barrier that surrounds the cell, separates internal contents from outside

Nucleoid region

Irregularly shaped, non-membrane-bound region in prokaryotic cells housing cell’s genetic material

Binary Fission

Asexual reproduction, extremely rapid reproduction, rapid mutation rates, prokaryotic reproduction

Transformation

Cells scavenge and use loose bacterial DNA floating in environment

Transduction

Bacterial DNA transferred from one bacterium to another through an intermediary

Conjugation

Direct transfer of genetic material between bacterium, involves “sex pilus” and a gene called F-factor

F-factor

F stands for fertility, bacterial plasmid that allows bacteria to transfer genetic material in conjugation

Relaxosomes

Protein assemblage that unwinds plasmid DNA facilitating transfer of plasmid DNA during conjugation

Transferosomes

Protein assemblage that forms a pore connecting membranes of two conjugating bacterial

Obligate anaerobe

Organisms that use fermentation/anaerobic respiration, use NO₃-/SO₄^2- instead of oxygen (oxygen toxic to metabolism)

Obligate aerobe

Organisms that use aerobic (oxygen-based) cellular respiration

Facultative anaerobe

Use aerobic respiration if oxygen is present, fermentation if oxygen is not present

Chemolithoautotrophy

Organisms that obtain high-energy electrons for carbon fixation from inorganic compounds in rocks, obtain energy from nitrogen, sulfur, iron, or hydrogen

Nitrogen Fixation

Conversion/reduction of atmospheric nitrogen to ammonium ion by certain microbes due to biological and industrial processes as well as lightening

Heterocyst

Specialized cells that only fix nitrogen

Gram Staining

Stain allows you to see if bacteria are cocci (round) or bacilli (rod-shaped), illustrates how cells group together (pairs, chains, clusters), gram positive vs gram negative (thick layer of peptidoglycan or thin layer of peptidoglycan respectively)

Bacteria responsible for Oxygen Crisis

Cyanobacteria, first used H2O for photosynthesis, produced oxygen into the atmosphere — most prolific producers of atmospheric oxygen

Given rise to eukaryotic mitochonrdia?

Proteobacteria

Given rise to eukaryotic chloroplasts

Cyanobacteria

Most common STD and most deadly bacterium?

Chlamydia - Gram Positive (TB/Anthrax) most deadly

Extremiphile

Organism living in an extreme place

Halophile

Saline-loving organism

Thermophile

Heat-loving organism

Psychrophile

Cold-loving organism

Acidophile

Acid-loving organism

Alkaliphile

Alkali-loving organism

Methanogen

Archaea that produces methane instead of carbon dioxide as respiratory byproduct in low oxygen conditions

Producer

Organisms that form organic matter by taking energy from abiotic sources to make sugar or other organic compounds

Decomposer

Soil bacteria that break down decaying vegetation and animal flesh, retain nutrients and prevent the loss of nitrogen, phosphorus, and sulfur

Pathogen

Organisms that can cause disease

Mutualist

Organisms that interact with each other such that benefits are obtained by each organism

Symbiont

Organism that lives in close, long-term relationship with another organism of a different species, can be helpful/harmful/neutral

Host

Larger organisms that harbors, feeds, or supports a smaller organism

Substrate

Surface/base on which an organism lives, grows, or attaches itself

Desiccation

Process of extreme drying or completely removing moisture from something