What is the definition of a reciprocal cross? 1. a cross wherein self-fertilization or mating with another organism of the same genotype occurs 2. a set of two crosses wherein a wild-type male is mated with a mutant female and a mutant male is mated with a wild-type female 3. a cross wherein a dominant phenotype individual is mated with a recessive phenotype individual 4. cross wherein a hybrid is crossed with a parental genotype individual Genetics often involves calculating the probability of events, such as the probability of being born with a genetic disorder. To address many types of genetics problems, the multiplication and addition rules of probability are applied depending on the situation When do you use the multiplication rule? mutually exclusive events events with infinite possible outcomes dependent events independent events When do you use the addition rule? 1. independent events 2. dependent events 3. events with infinite possible outcomes 4. mutually exclusive events

Proteins are the workhorses of the cell, controlling virtually every reaction within as well as providing structure and serving as signals to other cells. proteins are long chains of  amino acids  , and the exact sequence of the amino acids determines the final structure and function of the protein. instructions for that sequence are encoded in  genes  . to make a particular protein, a messenger ribonucleic acid (mrna) copy is made from the gene (in the process called  transcription  ), and the mrna is transported to the  ribosome  . protein synthesis, also called  translation  , begins when the two ribosomal subunits link onto the mrna. this step, called initiation, is followed by elongation, in which successive amino acids are added to the growing chain, brought in by transfer rnas (trnas). in this step, the ribosome reads the  nucleotides  of mrna three by three, in units called  codons  , and matches each to three nucleotides on the trna, called the anticodon. finally, during termination, the ribosome unbinds from the mrna, and the  amino acid  chain goes on to be processed and folded to make the final, functional protein