heredity Flashcards
heredity
the passing of genetic traits from parent to offspring
dominant trait
the trait observed in the first generation when parents that have different traits are bred.
recessive trait
a trait that is apparent only when two recessive alleles for the same characteristic are inherited.
genes
one set of instructions for an inherited trait.
alleles
one of the alternative forms of a gene that governs a characteristic, such as hair color.
phenotype
an organism’s appearance or other detectable characteristic.
genotype
the entire genetic makeup of an organism; also the combination of genes for one or more specific traits.
probability
the likelihood that a possible future event will occur in any given instance of the event.
meiosis
a process in cell division during which the number of chromosomes decreases to half the original number by two
sex chromosomes
one of the pair of chromosomes that determine the sex of an individual.
pedigree
a diagram that shows the occurrance of a genetic trait in several generations of a family.
DNA
Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses.
nucleotide
in a nucleic-acid chain, a subunit that consists of a sugar, a phosphlate, and a nitrogenous base.
mutations
a change in the nucleotide-base sequence of a gene or DNA molecule.
RNA
ribonucleic acid, a nucleic acid present in all living cells.
