Unit 5 Flashcards
A pair of chromosomes bearin similar sets of genes, genes coding for the same trait will be at identical locations but may code for different forms of the trait, each chromosome is reffered to as a homologue
Homologous pair
A filamentous structure in the nucleus of the cell composed of DNA and protein, genes are located along the DNA
Chromosome
A region of a chromosome that can be identified as having a role in the development of a trait, the sequence of nucleotides in a DNA molecule that codes for the synthesis of a protein of RNA, the location of a gene on a chromosome is its “locus”
Gene
One of the various forms of a gene at a particular locus on a chromosome, widows peak and straight are two alleles of the gene for type of hairline, a stigmatism and normal are two alleles for a gene that controls vision
Allele
The allele that masks the expression of other alleles, the dominant allele is represented by an uppercase letter, the allele that is expressed, if present, astigmatism is dominant over normal vision
Dominant allele
The allele that can have its expression masked by the expression of the dominant allele, represented by a lower case letter, normal vision is recessive to astigmatism
Recessive allele
Having a pair of identical alleles
Homozygous
Having two different alleles
Heterozygous
The genetic makeup of an individual
Genotype
The manifestation of a trait having an astigmatism
Phenotype
Parental generation
P
First, second, filial generation
F1, F2
A grid used to show all of the possible genotypes of the offspring and to determine the probable phenotypic ratios
Punnet square