Genetics Test Flashcards
Genotype
the genetic makeup or set of alleles on a chromosome (AA or Cc)
Phenotype
The physical appearance of the genotype such as hair color (Bb=brown hair)
All uppercase or lowercase letters as genotype
Homozygous (dominant for upper or recessive for lower)
One upper and one lowercase letter as genotype
Heterozygous (the upper letter always takes dominance)
If two homozygous dominant parents have children, what are the genotypic and phenotypic ratios of the offspring? (#:#:# and %:%:%)? Include the genotype (Ex: Aa)
100% will be HH (homozygous dominant)
If two homozygous recessive parents have children, what are the genotypic and phenotypic ratios of the offspring? (#:#:# and %:%:%)? Include the genotype (Ex: Aa)
100% will be hh (homozygous recessive)
If a homozygous dominant and a homozygous recessive have children, what are the ratios (include the genotype).
100% heterozygous
If there are two dihybrid, heterozygous parents, what are the genotypic and phenotypic ratios of the offspring? (#:#:# and %:%:%)? Include the genotype (Ex: Aa)
9:3:3:1
If two monohybrid heterozygous parents have children, what are the genotypic and phenotypic ratios (#:#:# and %:%:%)? Include the genotype (Ex: Aa)
Genotypic-1:2:1 (25% HH:50% Hh:25% hh)
Phenotypic- 3 (dominant - Hh or HH) : 1 (recessive - hh)
Complete Dominance
The presence of a dominant allele overshadows the other recessive allele - red OR white (RR or rr or Rr)
Incomplete Dominance
Both alleles “blend” together to form a new genotype and phenotype - pink
Co-dominance
both alleles play a role - red and white stripes or AB blood type
Aa or AB (hybrid-heterozygous or purebred-homozygous?)
hybrid-heterozygous
AA or bb (hybrid-heterozygous or purebred-homozygous)
purebred-homozygous
What are sex-linked traits? (X-linked traits)
diseases that are more likely for males to have since they only need one of the trait to show up in the X chromosome to have it (as the Y chromosome is too short to ‘hide’ the trait) females need to have two of the trait to show up due to having two X chromosomes
What is polygenic inheritance?
two or more genes that affect one trait (skin color, etc)
What is the Law of Segregation?
The separation of alleles during gamete separation.
Monohybrid
When there is one trait being differed on (brown or black hair)
Dihybrid
When there are two traits being differed on (brown or black and curly or straight hair)
Autosomal Trait (pedigree)
Trait that is located on an autosome (non-sex chromosome)
XY
male
XX
female
Pedigree Chart: Square
Male
Pedigree Chart: Circle
Female
Pedigree Chart: Filled-in
Affected
Pedigree Chart: Not filled-in
Not affected
