Polymorphic genes

TASK 1: Genetic determination of blood groups

Diagnostic kit for determination the ABO blood group system (monoclonal)

  • monoclonal Anti-A
  • monoclonal Anti-B
  • diagnostic cards
  • stick for mixing reagents with blood samples
fig.

Fig.: Diagnostic kit for determination the ABO blood group system (monoclonal).

Principle: agglutination technique, which is based on antigen / antibody reaction

Procedure:

  1. Place one drop of the monoclonal antiserum Anti-A within each of the blue circles
  2. Place one drop of the monoclonal antiserum Anti-B within each of the yellow circles
  3. Place one drop of blood within the each of the red circle (press on the bottom of the fingertip with the thumb of the same hand and quickly prick the fingertip with the help of a needle)
  4. Use a stick to mix the blood with monoclonal antiserum. Mix each sample with new edge of stick.

Evaluation:

  • The results are visible within 1 minute after mixing the diagnostic card with gentle rocking motion.
  • Positive reaction (agglutination) indicates the presence of the corresponding antigen on the red blood cells.
  • The negative reaction (no visible agglutination) indicates the absence of the corresponding antigen on the red blood cells.
  • The corresponding blood group is determined by the following table.
Reaction with diagnosticum Blood
group
Anti-A Anti-B
+ - A
- + B
+ + AB
- - 0

A - has on red blood cells agglutinogen A and produces anti-B antibodies

B - has on red blood cells agglutinogen B and produces anti-A antibodies

AB - has on red blood cells agglutinogens A and B and produces no antibodies

0 - have no agglutinogens and produces antibodies against both agglutinogens


The representation of blood groups in Czech Republic:

A = 45%

0 = 30-35%

B = 15-20%

AB = 5-7%

TASK 2:

    In rabbits, there is allele set with dominance in this order: colored fur C, Himalayan albinism ch, and albinism ca.
  1. What color of fur can be expected in offspring after crossing of two homozygotes one with colored fur and the second with Himalayan albinism?
  2. What are the genotypes of rabbits with colored fur and Himalayan albinism, if they had these offspring: 1/2 colored, 1/4 Himalayan albinism and 1/4 albinism?

Genetics of blood groups - examples

Humans:

  1. What blood groups are expected in offspring of parents with genotypes IAi and IBi ?
  2. What are the genotypes of parents, if father has blood group AB, mother B and their children 1/4 A, 1/4 AB and 1/2 B.
  3. Which of two men can be excluded as a father? Mother has blood group B, children 0, first man has A and second has AB.
  4. Parents are heterozygotes in blood groups B. What is the probability that their firstborn son will inherit the group B? And what is the probability, if the firstborn child is daughter?
  5. Parents are heterozygotes in blood groups A. What is the probability that their two children will inherit the group A?
  6. Mother has blood group B and her child A. Mother said, that father of child is man with blood group AB. Is this possible?
  7. During one night in one hospital four children with blood groups A, B, AB and 0 were born. Due to mistake of nurse we do not know which child was born to which mother. Therefore the blood groups of all four pairs of parents were examined. First parents have blood groups B x B, second have 0 x AB, third parents have groups A x B and fourth pair have groups 0 x 0. Is it possible to determine which parents have which children? If yes, which children belong to first parents, which to second parents, to third and fourth parents?
  8. What are the blood groups of men, which can't be fathers if we know blood groups of mother and child: a) mother 0, child A, b) mother 0, child 0, c) mother A, child B, d) mother AB, child B

Animals:

  1. A cat with blood group B has been mating with the tomcat with an unknown blood group. Four kittens have blood group A and three blood group B. What are the genotypes of parents and kittens?
  2. A cat with blood group A has been mating with the tomcat (male) with blood group B. What blood groups can have their kittens?
  3. A cat with blood group AB had gradually kittens with two tomcats. All kittens from the first cast had blood group A, kittens from the second cast had blood groups A, AB or B. What blood groups had both tomcats and what are genotypes of parents and offspring?