| A | B |
|---|
| What did scientists discover about the relationship between genes and DNA? | DNA is the nucleic acid that stores and transmits the genetic information from one generation of an organism to the next |
| Hershey and Chase concluded that the genetic material of the bacteriophage was | DNA, not protein |
| transformation | when one strain of bacteria is changed into another form of bacteria |
| bacteriophage | one type of virus that infects and kills bacteria, it means bacteria eater |
| nucleotide | units that make up the long molecule known as DNA |
| base pairing | hydrogen bonds can only form between certain base pairs |
| Watson and Crick's model of DNA | was a double helix, in which two strands were wound around each other |
| During DNA replication the DNA molecule | separates into two strands, then produces two new complimentary strands following the rules of base pairing |
| Each strand of the double helix of DNA serves | as a template, or model, for the new strand |
| chromatin | is a substance made up of Eukaryotic chromosomes that contain both DNA and protein |
| histone | proteins that have that is tightly wrapped around by DNA |
| replication | a copying process in which a cell duplicates its DNA before is divides |
| DNA polymerase | the principal enzyme in DNA replication |
| What are the tree main types of RNA | messenger RNA, ribosomal RNA and transfer RNA |
| During transcription RNA polymerase binds to DNA and separates the DNA strands. | RNA polymerase then uses one strand of DNA as a template from which nucleotides are assembled into a strand of RNA |
| during translation | the cell uses information from messenger RNA to produce proteins |
| messenger RNA | this molecule carries copies of the instructions for assembling amino acids into proteins |
| ribosomal RNA | a protein that is assembled on the ribosomes |
| transfer RNA | this is a third type of RNA molecule that transfers each amino acid to the ribosome |
| transcription | a process whereby RNA molecules are produced by copying part of the nucleotide sequence of DNA into a complementary sequence in RNA |
| RNA polymerase | transcription requires this enzyme |
| promotor | RNA polymerase doesn't just bind to DNA anywhere, the enzyme will only bind to this region |
| intron | large pieces that are cut out of the RNA molecules while they are still in the cell nucleus |
| exon | the remaining portions of the RNA moleculesafter the introns are cut out of the RNA molecules |
| codon | consists of three consecutive nucleotides that specify a single amino acide that is to be added to the polypeptide |
| translation | the decoding of an mRNA message into a polypeptide chain |
| anticodon | the three bases on the tRNA molecule that are complementary to one of the mRNA codons |
| mutations | are changes in the DNA sequence that affect genetic information |
| point mutation | mutations that affect one nucleotide that occur at a single point in the DNA sequence |
| frameshift mutation | changes that shift the "reading frame" of the genetic message |
| gene mutations result from changes in | a single gene |
| chromosomal mutations involve | changes in whole chromosomes |
| operon | a group of genes that operate together |
| operator | region of chromosome in an operon to which the reporessor binds when the operon is "turned off" |
| hox gene | a series of genes that controls the organs and tissues that develop in various parts of the embryo |
| the lac genes are turned off | by repressors and turned on by the presence of lactose |
| most eukaryotic genes are controlled individually and have | regulatory sequences that are much more complex than those of the lac operon. |
