Dihybridism, polyhybridism and branching method

TASK 1:

Complete Punnett square for dihybridism and deduce phenotype ratio for offspring of two guinea-pigs with the same genotype RrBb (R - rough coat, r - smooth coat, B - black coat, b - white coat). There is the relation of complete dominance between the two alleles of both genes.

What offspring results from the back crossing?

TASK 2:

    Use the branching method for setting of genotypes of gametes produced by individuals with the following genotypes:
  1. RrssTtUU
  2. AaBBCcddEe
  3. KkllmmNnOOppQq

TASK 3:

Use the branching method for setting of genotype and phenotype ratios in offspring of parents with these genotypes: RrssTtUU x RrSsTTuu (between alleles of all genes is complete dominance).

TASK 4:

Use the method of branching for setting of genotype and phenotype ratio in offspring of parents with these genotypes: AaBBCcddEe x aaBBCcDdee (There is the relation of incomplete dominance between the two alleles of all genes).

TASK 5:

    Black rough and white rough guinea-pigs had 32 black rough, 33 white rough, 12 black smooth and 9 white smooth offspring (see task 1).
  1. What were genotypes of both parents?
  2. Use the branching method for determination of genotype frequencies of offspring.
  3. Use χ2 test for determination of significance of variation between obtained (empiric) and expected (theoretic) phenotype ratios (table values are here).

TASK 6:

    In pumpkins, white color (W) is dominant over yellow (w) and disk shape (D) is dominant over round shape (d). What are the genotypes of parents and offspring in the following crossings?
  1. White disk x yellow round (offspring: 1/2 white disk and 1/2 white round).
  2. White disk x yellow round (offspring: 1/4 white disk, 1/4 white round, 1/4 yellow disk and 1/4 yellow round).
  3. White disk x white disk (offspring: 28 white disk, 9 white round, 10 yellow disk and 3 yellow round).

TASK 7:

In hen, feathery legs (F) are dominant over featherless legs (f) and pea comb (P) is dominant over simple comb (p).

Two cocks (A and B) were mated with two hens (C a D). All of them had feathery legs and pea combs. Cock A mated with hens C and D had all offspring with feathery legs and pea combs. Cock B mated with hen C had offspring with feathery or featherless legs and only pea combs, while mated with hen D offspring had only feathery legs and pea or simple combs. What are the genotypes of parents (cocks and hens) and their offspring?