History of Life--Exam 1

dark matter

Matter that does not give off electromagnetic radiation.

Cyanobacteria

Photosynthetic prokaryotes that began adding oxygen to the early atmosphere. UV-resistant. anaerobic (no oxygen needed)

Three domains of life

1. Eubacteria- single cell 2. archaea- single cell 3. eukarya-- single and multicellular

evolution of a star

1. begins as nebula of dust, hydrogen, and helium gas 2. gravitational contraction 3. Heating by friction 4.Thermonuclear ignition- nebula so hot 5. Heavy element synthesis 6.star death

Charles Darwin

1st to make coherent theory of evolution in his book "Origin of Species" (1859)

sexual selection

A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.

dark energy

A mysterious force that appears to be causing the expansion of the universe to accelerate.

neutron

A subatomic particle that has no charge and that is found in the nucleus of an atom

nucleobases

Adenine, Thymine, Cytosine, and Guanine.

photosynthesis

CO2+H2O---> (CH20)+O2 This process probably came after the creation of ozone layer

Characteristics of life

use if energy, reproduction, contain and transmit information, respond to stimulus, cellular/molecular

Photochemical disassociation of water

water (H20) disassociates (breaks up H2O to H2=O) little oxygen on earth. photosynthesis of early organisms bels produce more oxygen

disassociation with UV

Ultraviolet light breaks water molecule apart releasing hydrogen and oxygen. hydrogen leaves atmosphere to space while, oxygen stays on earth.

gene

a molecular unit of heredity of a living organism

Murchison meteorite

amino acids found in meteorite as well as lipids ((fatty acids) lipids make cell membrane)

supernova

an exploding star that collapses on itself. Heavy elements are produced by a supernova

nebula

an immense cloud of gas (mainly hydrogen) and dust in interstellar space

radioactive decay

an unstable chemical. A spontaneous process occurs when unstable nuclei lose energy by emitting radiation

six kingdoms of life

archaea, animalia, plantae, bacteria, protista, fungi

redshift

as source moves away the wavelength gets longer and lines in spectrum shift to the red, frequency decreases

genetic drift

chance that produces change in a population

mutation

change in nucleotide sequence of the genome of an organism

Alfred Russel Wallace

created theory of evolution similar to Darwin around the same time as Darwin.

neutron star

dense body only formed of neutrons

DNA

deoxyribonucleic acid, the material that contains the information that determines inherited characteristics. Double-helix structure

RNA world hypothesis

describes how the Earth may have been filled with RNA-based life before it became filled with the DNA-based life we see today (RNA+amino acids= chance to make proteins)

genome

entirety of an organisms hereditary information can be encoded on DNA sequence

Endosymbiosis

eucaryotic cell components (organelles) 1. nucleus 2. mitochondria 3. plastids and chloroplasts (plants and algae)

fossil

evidence of ancient organism

Dollo's law

evolution goes one direction in time. It does not go backwards and is unique in time and will be extinct forever.

Lateral gene transfer

genes can transfer from one branch to another (ex. bacteria, sickness)

genotype

genetic composition. Vary in little ways to make us individuals

electron

negatively charged particle; located outside the atomic nucleus

most abundant gases on Earth

nitrogen, oxygen, hydrogen

lipids

nonpolar molecules that include fats, oils, and cholesterol head and tail hydrophilic and hydrophobic.

nuclear fusion

nuclear reaction in which two or more atomic nuclei collide at a very high speed and join to form a new type of atomic nucleus

Absolute dating

numerically recorded time

isotope

one of two or more atoms with the same atomic number but with different numbers of neutrons

Common features of life

organic compounds, nucleic acids, (DNA/RNA), proteins (and ribosomes)

metabolism

organic process that runs system and uses energy

chromosomes

organized structure of DNA and protein found in cells. Single piece of coiled DNA containing many genes and other nucleotide sequences

proton

positively charged particle

Natural Selection

process by which individuals that are better suited to their environment survive and reproduce most successfully.

homeostasis

process by which organisms maintain a relatively stable internal environment

chemosynthesis

process by which some organisms, such as certain bacteria, use chemical energy to produce carbohydrates (ex. organisms living by volcanic hotspots)

convergent evolution

process by which unrelated organisms independently evolve similarities when adapting to similar environments (ex. Birds, bats, bugs)

cell membranes

protects cells, but must let in nutrients and release waste. Cell is a container for reactions independent of environment

Iron Catastrophe

protoearth got too hot, turned molten gravity pulled the heavy objects to the bottom (iron mostly (and nickel)) and the lighter objects on the outer parts creating the layers of the earth

hox genes

regulatory genes. control other genes (like a leg) and can turn on and off other genes (like skin, hair etc on that leg)

vestigial structure

remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species

Oort Cloud

remnants of sun's nebula, ice and dust particles

black hole

remnants of supernova, with huge gravitational pull (light can't escape)

RNA

ribonucleic acid; a nucleic acid that plays an important role in the production of proteins.

stromatolites

rocklike structures composed of many layers of bacteria (photosynthetic) and sediment

Big Whack Hypothesis

small planet crashed into earth. fragments rotate around earth (forming a ring) small planet pulled in by earth's gravitational pull. becomes moon!

Relative Time Scale

Created by James Hutton. Shows evolution in chronological order.

Principle of Uniformitarianism

Natural laws have remained constant and unchanging over time.

Big Bang Theory

Occurred 13.37 billion years ago. Start of time itself. Hydrogen is 70% of the visible universe. Helium 28% of visible universe. Everything else 2%

Lyn Margulis

Suggested that chloroplasts & mitochondria previously lived on their own. They were one day Phagocytized & remained in the cell.

Linnean Classification

System to classify life: Domain,Kingdom, Phylum, Class, Order, Family, Genus, Species

central dogma

how information transfers over generations. basis of inheritance

law of superposition

in undisturbed sedimentary rock layers, the oldest rocks are on the bottom and the youngest rocks are on the top

Relative dating

looking at events relative to each other in time

meiosis

making of sex cells (gametes--egg & sperm)