Genetics Flashcards
What are alternate forms of genes at each locus called?
ALLELES
Alleles are variations of a specific gene that occupy the same locus on a chromosome.
When allelic genes are identical, what are they called?
HOMOZYGOUS
Homozygous examples include KK, CC, EE, cc.
What term describes different alleles at a given locus on a pair of chromosomes?
HETEROZYGOUS
Heterozygous examples include Kk, Cc, Ee.
What is the full complement of genes in an organism called?
GENOME
What does POLYMORPHIC mean in genetics?
2 or more alleles at a given locus
Some blood group systems, like the Rh system, exhibit more polymorphism than others.
What is meant by ANTITHETICAL in genetics?
Opposite antigens encoded at the same locus
Examples include Fy(a) and Fy(b) or K and k.
What inheritance pattern is characterized by equal expression of both inherited alleles?
CO-DOMINANT
For instance, if one parent passes the A gene and the other passes the B gene, both A and B will be expressed on red blood cells.
What does Independent Segregation refer to in Mendelian laws?
Passing of one gene from each parent to the offspring.
What does DOSAGE EFFECT mean in relation to antigens?
Certain antigens demonstrate stronger agglutination when expressed homozygously.
Which antigens demonstrate dosage effects?
- Duffy (Fy(a), Fy(b))
- Rh (except D)
- MNSs
- Kidd (Jk(a), Jk(b))
What is LINKAGE in genetics?
When genes are inherited together by being very close on a chromosome.
What are HAPLOTYPES?
Gene units that are very close together on a chromosome and often inherited as a unit.
What are SILENT GENES also known as?
AMORPHS
Silent genes have no detectable antigen product.
What role do SUPPRESSOR GENES play in genetics?
They suppress the expression of another gene to produce a NULL expression.
What is the difference between CIS and TRANS in genetic interaction?
- CIS: Genes on the same chromosome
- TRANS: Genes on opposite chromosomes
How can paternity be excluded in relationship testing?
- Direct exclusion
- Indirect exclusion
What is an OBLIGATORY GENE?
A gene that SHOULD be passed on by the alleged father to prove/disprove paternity.
What is DIRECT EXCLUSION?
A genetic marker inherited by the child but NOT found in mother or alleged father.
What is INDIRECT EXCLUSION?
Child lacks a genetic marker that should have been inherited.
What is the calculation for determining the frequency of blood phenotype?
Subtracting each frequency from 100 gives the percent of blood negative for each antigen.
What is the frequency of antigen K?
9%
What is the frequency of antigen c?
80%
What is the frequency of antigen Jk(a)?
77%
What is a Positive Control in antigen selection?
Heterozygous cell (single dose) for appropriate antigen.
What is a Negative Control in antigen selection?
A cell negative for the appropriate antigen.
