BackMendelian Genetics and Chromosomal Inheritance
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Terms in this set (20)
Mendel's Law of Segregation states that allele pairs separate during gamete formation, and each gamete receives only one allele of each gene.
Law of Independent Assortment states that alleles of different genes assort independently of one another during gamete formation.
A genotype is the genetic makeup of an organism, referring to the specific alleles present.
A phenotype is the observable physical or biochemical characteristics of an organism, determined by genotype and environment.
A test cross is used to determine an organism's genotype by crossing it with a homozygous recessive individual.
The F1 generation showed only the dominant trait, demonstrating dominance and segregation of alleles.
A dihybrid cross examines the inheritance of two different traits simultaneously.
Linked genes are located close together on the same chromosome and tend to be inherited together, violating independent assortment.
Recombination frequency measures how often crossing over occurs between two genes, used to map their distance on a chromosome.
The chromosomal theory of inheritance states that genes are located on chromosomes, which segregate and assort independently during meiosis.
Autosomes are chromosomes that do not determine sex; sex chromosomes determine the sex of an organism (e.g., X and Y in humans).
A sex-linked trait is a characteristic determined by a gene located on a sex chromosome, often the X chromosome.
Morgan provided evidence that genes are located on chromosomes by studying sex-linked traits in fruit flies.
Crossing over is the exchange of genetic material between homologous chromosomes during prophase I of meiosis.
Crossing over increases genetic variation by producing new combinations of alleles on chromosomes.
A pedigree chart tracks the inheritance of traits through generations in a family.
Incomplete dominance occurs when the heterozygote phenotype is intermediate between the two homozygotes.
Codominance occurs when both alleles in a heterozygote are fully expressed.
Pleiotropy is when one gene influences multiple phenotypic traits.
Polygenic inheritance involves multiple genes contributing to a single trait, resulting in continuous variation.