Heredity Flashcards
What is a gene?
A gene represents the genetic material on a chromosome that contains the instructions for creating a particular trait.
What is an allele?
It is one of several varieties of a gene.
What is a locus?
This refers to the location on a chromosome where a gene is located. Every gene has a unique locus on a particular chromosome.
What term describes the expression of an allele?
Phenotype
What term represents the actual alleles?
Genotype
Who is credited with the discovery of LAWS of SEGREGATION and INDEPENDENT ASSORTMENT?
Gregory Mendel
Describe the Law of Segregation
Separation of alleles and chromosomes to individual gametes (meiosis)
What is independent assortment?
The independent assortment of homologs in metaphase I as they are separated into opposite poles. This assortment is independent because the migration of homologues within one pair of homologous chromosomes does not influence the migration of other homologues.
When do you utilize a monohybrid cross?
Investigation of ONE trait
When do you utilize a dihybrid cross?
Ingestivation of TWO traits.
Inheritance pattern in which one allele is expressed as dominant to a second allele.
Complete (or full) dominance
Describe the genotypic frequencies resulting from the cross (TT x tt)
4/4 Tt
Describe the genotypic frequencies resulting from a monohybrid cross of two heterozygotes.
(Tt x Tt), we see 1/4 TT + 1/2 Tt + 1/4 tt
In a dihybrid cross of homozygous dominant and homozygous recessive plants with two traits, what are the genotypes of F1 generation? (YYRR x yyrr)
16/16 heterozygous YyRr
Describe the genotypic frequencies of the F2 generation (F1: YyRr)
1: YYRR
2: YYRr
2: YyRR
4: YyRr
1: yyRR
2: yyRr
1: YYrr
2: YyRr
1: yyrr