chapter 3 heredity Flashcards
heredity
the passing of genetic trains from parent to offspring
dominant trait
the trait in the first generation when parents that have different traits are bred
recessive trait
a trait that reappears in the second generation after disappearing in the first generation when parents with different traits are bred
gene
one set of instructions for an inherited trait
allele
one of the alternative forms of a gene that governs a characteristic, such as hair color
phenotyoe
an organisms appearance or other detectable characteristics
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
homologous chromosomes
chromosomes that have the same sequence of genes and the same structure
meiosis
a process in cell division during which the number of chromosomes decreases to half the original number by two divisions of the nucleus, which results in the production of sex cells
sex chromosome
one of the pair of chromosomes that determine the sex of an individual
pedigree
a diagram that shows the occurrence of a genetic trait in several generations of a family