Genetics Flashcards
(20 cards)
Allele
variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution.
Homozygous
both alleles for the gene are the same
Heterozygous
having two different alleles of a particular gene or genes
DNA (deoxyribonucleic acid)
Thread-like chain of nucleotides carrying the genetic instructions in a double-helix of anti-parrallel strands.
RNA (ribonucleic acid)
Singular strand, thread-like chain of nucleotides carrying genetic instructions for forming a protein
Genes
Composed of sections of DNA and control the way an organism develops, grows and functions. They are tightly coiled into x-shaped structures (chromosomes)
Dominant allele
dominant allele produces a dominant phenotype in individuals who have one copy of the allele, which can come from just one parent.
Recessive allele
A recessive allele does not produce a trait at all when only one copy is present.
Polygenic
multiple gene inheritance
Monohybrid x
A monohybrid cross is one in which both parents are heterozygous (or a hybrid) for a single (mono) trait.
Dihybrid x
A dihybrid cross describes a mating experiment between two organisms that are identically hybrid for two traits.
Phenotype
the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.
Genotype
the genetic constitution of an individual organism.
Wild-type allele
A term used to describe a gene when it is found in its natural, non-mutated (unchanged) form.
pure bred
not mixed or adulterated with any other substance or material.
Sex linked
Sex-linked, as related to genetics, refers to characteristics (or traits) that are influenced by genes carried on the sex chromosomes.
Law of segregation
Genes for a characteristic occur in pairs in an individual. One inherited from each parent
Law of independent assortment
When two or more characteristics are inherited, individual heredity factors assort independently giving different traits an equal opportunity to occur together
Codominance
a type of inheritance in which two versions (alleles) of the same gene are expressed separately to yield different traits in an individual.
Incomplete dominance (intermediate/partial)
a form of Gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype.
