Unit 5- Vocabulary Flashcards
Gene
A linear sequence of nucleotides along a segment of DNA on a chromosome; the basic unit of heredity.
Trait
An inherited characteristic or condition.
Chromosome
Structure made of DNA that carried the units of heredity.
Allele
Different form of a gene for a particular trait.
Dominant
The trait that is expressed if it is present; denoted with a capital letter.
Recessive
Trait that is only expressed when the dominant trait is not present; do noted with a lowercase letter.
Genotype
The actual combination of alleles for a trait.
Autosome
Chromosomes that determine characteristics other than gender of an organism.
Sex Chromosome
Chromosome that determines the gender of an individual; the 23rd pair of chromosomes in humans.
Karyotype
A picture of homologous chromosome pairs; used to do chromosomal studies of organisms.
Polygenic Inheritance
When traits are controlled by more than one gene.
Multiple Alleles
A gene that has more than one allele.
Sex Linked Trait
A trait controlled by a gene located on the sex chromosome.
Pedigree
A family record that shows which members inherit a specific trait over several generations.
Homozygous
When there are two of the same alleles for a trait; AA or aa.
Heterozygous
When there are two different alleles for a trait; Aa.
Complete Dominance
Type of dominance in which the heterozygote expresses the dominant trait.
Incomplete Dominance
Type of dominance in which the heterozygote expresses a blend of the dominant and recessive trait.
Codominance
Type of dominance in which they heterozygote expresses both the dominant & recessive trait.
Crossing Over
The exchange of corresponding sections between homologous chromosomes during meiosis.
Nondisjunction
Failure of homologous chromosomes to separate properly during meiosis; results in gametes with too many or too few chromosomes.
Law of Segregation
States that the members of a pair of homologous chromosomes separate during meiosis and are distributed to different gametes.
Law of Independent Assortment
When gametes are made, the genes for traits found on different chromosomes separate independently of each other.
Gel Electrophoresis
Laboratory method used to separate mixtures of DNA, RNA or proteins according to the size of the molecules.