DNA/Genetics vocabulary

DNA/Genetics Vocabulary

Trait-A characteristic that an organism can pass on to its offspring through its genes

Heredity-The passing of traits from parents to offspring

Genetics-The scientific study of heredity

Purebred-An organism that always produces offspring with the same form of a trait as the parent

Gene-A segment of DNA on a chromosome that codes for a specific trait

Alleles-The different forms of a gene

dominant allele-An allele whose trait always shows up in the organism when the allele is present

recessive allele-An allele that is masked when a dominant allele is present

Hybrid-An organism that has two different alleles for a trait; an organism that is heterozygous for a particular trait

Probability-The likelihood that a particular event will occur

Punnett square-A chart that shows all the possible combinations of alleles that can result from a genetic cross

Phenotype-An organism’s physical appearance, or visible traits

Genotype-An organism’s genetic makeup, or allele combinations

Homozygous-Having two identical alleles for a trait

Heterozygous-Having two different alleles for a trait

Codominance-A condition in which neither of two alleles of a gene is dominant or recessive

Sperm-A male sex cell                                           Egg-A female sex cell

Meiosis-The process that occurs in sex cells (sperm and egg) by which the number of chromosomes is reduced by half

messenger RNA-RNA that copies the coded message from DNA in the nucleus and carries the message into the cytoplasm

transfer RNA-RNA in the cytoplasm that carries an amino acid to the ribosome and adds it to the growing protein chain

Mutation-A change in a gene or chromosome