| A | B |
|---|
| Anticodon | three nucleotides in transfer RNA that bind to a codon in mRNA |
| Chromatin | material of chromosomes that consists of DNA and proteins |
| Codon | group of three nucleotides in mRNA that specifies an amino acid |
| DNA | (Deoxyribonucleic acid)-nucleic acid that transmits genetic information from one generation to the next and codes for the production of proteins |
| DNA replication | process in which DNA is copied |
| Exon | expressed sequence of mRNA; a region that remains in mRNA after the introns are removed |
| Genetic code | language of the instrucitons in DNA and RNA that code for the amino acid sequence of a polypeptide |
| Intron | intervening sequence that is removed from mRNA and thus not expressed |
| Messenger RNA (mRNA) | form of RNA that carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm |
| Nucleotide | compound made of a phosphate group, a nitrogenous base, and a 5-carbon sugar; forms the basic structural unit of DNA |
| Operator | special region of DNA to which the repressor binds |
| Promoter | special region of DNA to which RNA polymerase binds at the beginning of the process of transcription |
| Repressor | protein the blocks a gene's transcription by binding to the operator |
| Ribosomal RNA (rRNA) | form of RNA that is an important component of ribosomes |
| RNA (Ribonucleic acid) | prinicpal molecule that carries out the instructions coded in DNA |
| Transcription | process in which the nucleotide sequence of a DNA molecule is copied into RNA |
| Transger RNA (tRNA) | form of RNA that carries an amino acid to the ribosome during the assemble of a protein |
| Transformation | process of reproduciton in which genetic material is added to or replaces portions of a bacteria's DNA |
| Translation | process by which the nucleotides in mRNA are decoded into a sequence of amino acids in a polypeptide |
| Nucleic acid in eukaryotes and prokaryotes | in eukaryotes it is double-stranded or DNA; in prokaryotes it is single-stranded or RNA |
| Frederick Griffith (1928) | did pnemonia experiment-some molecule or group of molecules had changed the harmless rough bacteria into deadly smooth bacteria, he named this process transformation |
| Avery (1944) | furthered Griffith's idea-treated bacteria-transformation was blocked when DNA was-concluded that genes are made of DNA |
| Hershey and Chase (1952) | did bacteriophage experiment- concluded by treating a bacteriophage with radioactive isotopes that the genetic material in a bacteriophge was DNA not protein |
| DNA Replication is... | enzymes separate the two strands, new strands are synthesized that base-pair to the original strands-DNA is duplicated and the cell is ready for division |
| Chargaff (1950) | established Chargaff's rule- in DNA in almost every organism, the amount of adenine is equal to the amount of thymine, and the amount of cytosine is equal to the amount of guanine |
| Watson and Crick | discovered shape of DNA-double helix-weak hydrogen bonds held together paired sequences of nucleotides to explain Chargaff's rule |
| Franklin and Wilson (1953) | Used a technique called x-ray diffraction to study the structure of DNA |
| Transcription is... | when part of the nulceotide sequence of a DNA molecule is copied into RNA-carried out by RNA polymerase, an enzyme the binds directly to DNA-RNA polymerase produces a strand of RNA, one nulceotide at a time, by matching base pairs with the nucleotides in DNA (Uracil replacing thymine) |
| Translation is... | nucleotides in mRNNA are decoded into a sequence of amino acids in a polypeptide-mRNA is transcribed in the nucleus, then enters the cytoplasm and attaches to a ribosome-begins at AUG-start codon, each tRNA contains and anticodon(three nucleotides that base pair to a specific codon in mRNA)-tRNA brings amino acid and the ribosome binds them to form a polypeptide |
| Lac genes do what? | code for a protein that must be expressed for the cell to use lactose -genes are expressed only when lactose is present -a protein called a lac repressor is a DNA-binding protein the blocks that gene's transcription -repressor binds to the operator so that the RNA polymerase cannot move past the operator to reach the lac genes -when lactose binds to the repressor, the repressor changes shape and fgalls off the DNA, making the lac genes ready to be transcribed |
| What are Introns and Exons? | Introns are the discarded parts of DNA after editing, Exons are the remaining pieces that are used and spliced together |
| Adaptation | evolution of physical and behavioral traits that make organisms better suited to survive in their environment |
| Artificial selection | method of selective breeding of organisms to produce offspring with desirable characterisitics |
| Common Descent | priniciple that species have descended from common ancestors |
| Evolution | process of change over a period of time |
| Fitness | an organisms ability to successfully pass on its genes to its offspring |
| Fossil | preserved bone or other trace of an ancient organism |
| Homologous structure | structures that have a common origin but not necessarily a common function |
| Natural selection | process in nature that over time results in the survival of the fittest |
| Vestigial Organ | structure in an organism that seems to have little or no obvious purpose |
| Artificial selection | when humans pick out animals to breed because of desirable characteristics |
| Charles Darwin | traveld on the HMS Beagle around the world-found fossils of organisms no longer in existence-noticed adaptations in animals that were similar but not quite the same-used the term fitness to describe how well an animal could survive-was fascinated by Galapagos |
| Gene pool | all the alleles of all the genes of the members of a population that interbreed |
| Genetic Drift | random change in allele frequency, often producing offspring that will be different from the original population by chance |
| Gradualism | theory that evolutionary change occurs slowly and streadily over long periods of time |
| Mutation | abrupt alteration in the genetic information of a cell |
| Puctuated equilibrium | patteren of long periods of stability that are interrupted by episodes of rapid change |
| Reproductive Isolation | separation of different species that cannot interbreed |
| Speciation | formation of a new species brought about by genetic changes that prevent breeding between the new, genetically different groups |
| Inheritable variation | random changes in DNA or mutation-gene shuffling that occurs when the egg and sperm are produced-single gene traits;there are three possible phenotypes-polygenic traits are controlled by two or more genes there are a large number of phenotypes possible-polygenic traits make a bell shaped curve |
| stabilizing selection | organisms near the center of the bell curve are more fit than the organisms at either end |
| directional selection | organisms near the center of the bell curve are more fit than the organisms in the middle or at the other end-will cause the bell curve to shift |
| disruptive selection | organisms at either end of the bell curve are more fit than the organisms in the center of the bell curve-natural selection acts strongly agains organisms in the center-bell curve will split into two and speciation may or may not occur |
| Adaptive radiation | pattern of evolution in which selection and adaptation lead to the formation of a new species in a relatively short period of time |
| Analogous structures | similar in appearance and function but dissimilar in anatomical development and origin |
| Biodiversity | variety of organisms, their genetic imformation and biological communities in which they live |
| Ecosystem | collection of organisms-producers, consumers, and decomposers-interacting with each other and with their physical environment |
| Convergent evolution | process by which unrelated species independently evolve superficial similarities when adapting to similar environments |
| Ecosystem deversity | variety of habitats, living communities and ecological processes in the living world |
| Genetic Diversity | genetic material in the gene pool of a species, variety of different forms of genes present in a population |
| Molecular Clock | theory that mutations in DNA occur at a constant rate, used to estimate time frames of departure from common ancestry |
| Species Diversity | number and variety of different life forms |
| Molecular unity | many genes are shared by a wide range of organisms-genes that carry instructions to build ribosomes in yeasts and in humans-both myosine, muscle protein used in multicellular organisms that helps contract muscles-found in yeast, yet yeast has no muslces nor does it move-it moves cell parts |
| Autotroph | organism that uses energy from the sun to chage simple nonliving chemical nutrients in its environment into living tissue |
| Consumer | organism that eats other organisms to obtain energy and nutrients |
| Decomposer | organism that feeds on the dead bodies of animals and plants or on their waste products |
| Ecological pyramid | diagram showing the decreasing amounts of energy, living tissure, or number of organisms at successive trophic levels |
| Ecology | scientific study of interactions between different kinds of living things and the environments in which they live |
| Food chain | sequence of organisms related to one another as food and consumer |
| Food web | interconnecting food chains in an ecological community |
| Heterotroph | organism that cannot manufacture its own food |
| Nutrient cycle | path along which nutrients that are available in fixed quantities on earth are passed from one organism to another and from one part of the biosphere to another |
| Primary producer | organism that uses energy from the sun to change simple nonliving chemical nutrients in its environment into living tissue |
| Trophic level | feeding level in the flow of food energy and nutrients from primary producers to highest level consumers |
| Porifera | porebearing-lice in sea and fresh water, no symmetry, lacks tissures and organs; sponges |
| Cnidaria | Stinging cells-live in sea and fresh water, long tentacles with stinging cells to catch prey, radial symmetry; jellyfish, corals, sea anemones, hydras |
| Platyhelminthes | flat worms-cephalization-head, sensory organs located in the anterior end; bilateral symmetry with left and right mirror images; Planarians, flukes, tapeworms |
| Nematoda | roundworms-Many are parasitic, tubelike digestive systems with a mouth and anus, first phylum to develop that digestive system-Hookworms, pin worms, heat worms, intestinal roundworms, trichina |
| Mollusca | soft bodied-Univalves have one shell(snail) bivalves have two hinged shells (clams) some have no shell (slugs); octopi and squid release ink as a defense; Clams, mussels, oysters, scallops, snails, slugs, octopi, squid |
| Annelida | segemented worms- all members have segmented bodies; Earthworms-recycle organic matter; leeches-feed on blood; feather dusters-have feathery gills |
| Echinodermata | spiny skin-no cephalization, five part radial symmetry; starfish, urchins, sea lilies |
| Arthropoda | jointed legs, external skeleton, and segmented body; subphylum chelicerates(spiders and scopians); subphylum crustacea(crabs, crayfish, pill bugs) insecta(insects) |
| Chordata | chordates-have an endoskeleton with a stiff rod called a notochord-sea squirt |
