BIOL 205 Midterm 1

reductionism

the reduction of complex systems to simpler components that are more manageable to study. easier to determine what each part does

emergent properties

New properties that arise with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases. new functions become possible as smaller parts work together

key features of life

1. cells are the basic unit of life, 2. atp is the basic unit of energy, 3.dna is the basic unit of heredity, 4.evolution explains the unity and diversity of life, 5.all life is interconnected

Aristotle

one the the first written forms of categorizing life in order of complexity (Scala naturae/great chain of being)

Carolus Linnaeus

Father of taxonomy. categorized based on physical similarities/differences.

kingdom

First and largest category used to classify organisms

genus species

Scientific names of organisms. most specific , each species is unique

science is an attempt to understand...

natural (physical world)

science involves what we can...

perceive with our senses/instruments that can extend our senses

science cannot...

explain the supernatural

science gathers...

evidence/data (conduct experiments)

science is...

falsifiable, able to challenge ideas.

hypothesis

proposed explanation for a natural phenomenon

2 components of scientific theory

a pattern, and a process

does biology have laws?

no because life is unpredictable and dynamic

Robert hooke

first to observe "small chambers" in cork and call them cells.

Anton van Leeuwenhoek

made first simple microscope, first to describe single celled organisms

cell theory

idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells (Virchow)

if all cells come from pre-existing cells...

1. all individuals in a pop. of single celled organisms have a common ancestor

2. all cells from a multicellular organism originate from a single cell (zygote)

3. zygotes arise from the division of pre-existing cells

spontaneous generation

Hypothesis stating that life could arise from nonliving matter.

Louis Pasteur

swan flask experiment to disprove spontaneous generation

What did Louis Pasteur conclude about bacteria?

they are environmental microbes that contaminate material and grow until observed

evolution by natural selection

suggests all species are related by a common ancestor

what is natural selection

a species characteristics are traits that became modified over time

plato's thoughts surrounding life

every organism is a perfect essence created by supreme being. variations can be ignored due to them being distortions from our brain.

Aristotle's beliefs on life

all life is created perfectly, independently, and permanently. humans are special and separate from the rest of nature

what does special creation say?

1. earth and life were created ~6000 years ago

2. all species created individually

3. all organisms created perfectly

4. species are immutable

Lamarck

French naturalist who proposed that evolution resulted from the inheritance of acquired characteristics (1744-1829). traits that you acquire in your lifetime can be passed on to your offspring.

Darwin

natural selection and selective pressure

Lyell

'Father of uniformitarianism' - belief that the earth was old, and catastrophism happened slowly

Malthus

said human population cannot continue to increase exponentially; consequences will be war, famine & disease. pops. produce more offspring than the environ. can support

artificial selection

Breeding organisms with specific traits in order to produce offspring with identical traits.

if a trait is beneficial...

increase fitness

if a trait is detrimental...

decrease fitness

if a trait is neutral...

not affect fitness, may become vestigial structure (used to be helpful but as the world changed it was not needed anymore)

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

descent with modification

throughout long periods of time, the characteristics of a population may change compared to the ancestral population

natural selection does not...

create traits. only changes the proportion of traits.

all organisms alive today...

1. cellular organisms

2. dna stores genetic info

3. atp as primary energy source

homologous structures

Structures in different species that are similar because of common ancestry. modified over time due to selective advantage. descent w/ modification.

molecular biology

1. dna sequences of closely related species are similar (diverged more frequently)

2. dna sequences of distantly related species are less similar (diverged long time ago)

what do mutations result in

in evolution/speciation

big bang theory

origin of the universe, 12-14 billion years ago

condensation theory

-subatomic particles condense to form larger things

when was the earth formed

about 4.5 billion years ago

fireball earth

molten rock heated by collisions. earth cooled down and a crust formed

the atmosphere has

greenhouse gasses

conditions of early earth (3)

1. anaerobic, 2. mostly water, atmosphere of inorganic molecules

sources of energy in early earth

solar energy, radioactivity, UV radiation, lightning, volcanoes, underwater volcanoes, thermal energy

abiogenesis

very simple life forms spontaneously appeared through chemical reactions and became increasing complex. led to the first cellular organisms

when did life appear

3.5 billion years ago

what is the panspermia theory

a theory that life did not originate on Earth but arrived in the form of bacterial spores or viruses from an extraterrestrial source

could simple organic molecules been rained down on earth from space?

amino acids from asteroids

primordial soup

a solution rich in organic compounds in the primitive oceans of the earth, from which life is hypothesized to have originated.

polymerization

small molecules chemically combined into a big chain of molecules.

Amino acid monomers are linked together

protein

nucleic acid monomers linked together

dna/rna

carbon monomers linked together

lipids

sugar monomers linked together

polysaccharides

3 essential things in order for life to prosper

stability/order, metabolism, replication

central dogma

DNA -> RNA -> Protein

"Protein World" Hypothesis

Protein molecules were the first information storage.

problem with protein world hypothesis

proteins don't self replicate by themselves

evidence for protein world

probiotic soup full of nucleic acids, efficient catalysts

evidence for dna world hypothesis

probiotic soup full of nucleic acids, dna stores info accurately

problem with dna world hypothesis

dna requires protein to replicate, not catalytic

evidence for rna world hypothesis

probiotic soup full of nucleic acids, can self replicate, catalytic

problem with rna world hypothesis

no known catalytic rna today that can self replicate

examples of simple metabolism

glycosis and fermentation

complex metabolic processes

photosynthesis, and respiration

how were protocells able to be stable?

used lipids in form of membranes, stable lipids - survive and reproduce

why is dna a more efficient information storage

more stable, more resistant to mutation

why were catalytic reactions carried out by proteins rather than rna

more efficient catalysts, synthesized form rna templates

what is Luca?

'last universal common ancestor', the first real cell

Great Oxygenation Event

due to oxygenic photosynthesis, cells would excrete oxygen - oxygen would accumulate in the ocean - too much oxygen in the ocean would escape into the atmosphere

how did the great oxygenation event affect current life on earth

species that couldn't handle the oxygen died off and the species that could remove the oxygen were selected for

2 things that occurred that signified the beginning of our world

aerobic respiration, ozone layer (terrestrial life emerged)

What are prokaryotes

A cell without a nucleus, and no membrane bound organelles

What are the types of prokaryotes

divided into bacteria and archaea

endosymbiotic theory

a theory that states that aerobic bacteria started living inside archaea due to the archaea's protective nature and could provide nutrients. the bacteria would take the unwanted oxygen and produce atp. symbiotic relationship that became permanent. now called eukaryotes.

what organelle did the bacteria from the endosymbiotic theory become (2)

mitochondria and chloroplasts (plants)

difference between bacteria and archaea?

bacteria has a cell wall of peptidoglycan, archaea has a cell wall of murein

what features does a eukarya have (5)

eukaryotes, uni or multicellular, multiple linear DNA molecules, cell walls of cellulose, chitin and pectin large

monosaccharide examples

glucose, fructose and sucrose

what is the function of monosaccharides

used in metabolism

polysaccharide examples

glycogen, cellulose, starch

What is the function of a polysaccharide?

long term energy store and structural support

dna function

helical structure used to store genetic information

rna function

turn genetic info into protein, monomers used as cell energy molecules

what pairs with adenine?

thymine

what pairs with cytosine?

guanine

what do nucleotides consist of? (3)

pentose sugar, phosphate group, nitrogenous base

what are the two pentose sugars?

deoxyribose and ribose

what are lipids?

water-insoluble molecules composed of mostly hydrocarbons

saturated fats

fats that are solid at room temperature and have no double bonds

unsaturated fats

fats that remain liquid at room temperature and have a double bond

function of fats

long term energy storage and insulation

what is a triglyceride composed of and its function

an energy-rich compound made up of a single molecule of glycerol and three molecules of fatty acid.

phospholipids

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

ogliopeptides

proteins with less than 10 amino acid groups and are used for cell signalling and food sources