Mendelian Genetics Flashcards
Define the term: Gene
A gene is a sequence of DNA that encodes for a specific trait/phenotype within an organism.
Define the term: Locus
A locus refers specific point on a chromosome where a particular gene is located.
Define the term: Allele
An allele is one copy of a specific DNA sequence (a gene) that exists as two or more copies of the same gene.
Define the term: Genotype
In a broad sense, the term “genotype” refers to the genetic makeup of an organism; in other words, it describes an organism’s complete set of genes. In a more narrow sense, the term can be used to refer to the alleles, or variant forms of a gene, that are carried by an organism.
https://www.nature.com/scitable/definition/genotype-234/#:~:text=In%20a%20broad%20sense%2C%20the,are%20carried%20by%20an%20organism.
Define the term: Phenotype
the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.
Define the term: Homozygous
Refers to a genotype where boh alleles are either dominant or recessive. We typically refer to a homozygous genotype as either homozgous dominant (TT) or homozygous recessive (tt).
Define the term: Heterozygous
Refers to a genotype where there are mixed alleles (one copy of the recessive allele and one copy of the dominant allele).
Define the term: Dominant Allele
An allele that expresses its phenotypic effect even when heterozygous with a recessive allele; thus if A is dominant over a, then AA and Aa have the same phenotype.
https://groups.molbiosci.northwestern.edu/holmgren/Glossary/Definitions/Def-D/dominant_allele.html
Define the term: Recessive Allele
A type of allele that when present on its own will not affect the individual. Two copies of the allele need to be present for the phenotype to be expressed.
https://www.genomicseducation.hee.nhs.uk/glossary/recessive-allele/#:~:text=Definition,the%20phenotype%20to%20be%20expressed.
