clone – an organism that is genetically identical to the organism from which it was produced
chromosome – rod-shaped structures made of condensed DNA that are located in the nucleus of every cell in an organism
dominant –a trait that always shows up in the organism or covers up another trait
double helix- shaped like a twisted ladder
DNA – (deoxyribonucleic acid): molecule that is the master copy of an organism’s information code
gene – section of DNA on a chromosome that contains instructions for making specific proteins
genetic engineering – biological and chemical methods to change the arrangement of a gene’s DNA to improve crop production, produce large volumes of medicine, and change how cells perform their normal function
gene therapy – insertion of working copies of a gene into the cells of a person with a genetic disorder in an attempt to correct the disorder
genetics – the study of how traits are inherited through the actions of alleles
genome – all of the DNA in one cell of an organism
genotype – the genetic makeup of an organism or allele combinations
heredity – passing of traits from parents to offspring
heterozygous – an organism with two different alleles for a trait
homozygous – an organism with two alleles for a trait that are exactly the same
mutation – any permanent change in an organism’s genetic material
phenotype – the physical trait of an organism (ex. tall pea plant, eye color, )
Punnett squares – special charts used to show possible combinations of the cross between two sets of alleles
recessive – weaker trait in genetics; a trait that seems to disappear because it is “hidden” by the dominant trait or the alleles must be homozygous for the recessive trait to appear
selective breeding – process of selecting a few organisms with desired traits to serve as parents of next generation
Gregor Mendel – (1822-1844) was an Augustinian priest and scientist, who gained posthumous fame as the figurehead of the new science of genetics for his study of the inheritance of certain traits in pea plants. Mendel showed that the inheritance of these traits follows particular laws, which were later named after him.
Rosalind Franklin – (1920-1958) was a British biophysicist, physicist, chemist, biologist and X-ray crystallographer who made important contributions to the understanding of the fine molecular structures of DNA, RNA, viruses, coal and graphite. Franklin is still best known for her work on the X-ray diffraction images of DNA. Her data, according to Francis Crick, was "the data we actually used" to formulate the famous 1953 hypothesis regarding the structure of DNA.
James Watson and Francis Crick – using x-ray diffraction data collected by Rosalind Franklin, proposed the double helix or spiral staircase structure of the DNA molecule in 1953.