Dihybrid inheritance Flashcards
1
Q
what are dihybrid crosses used for?
A
show inheritance of 2 different characteristics, caused by 2 genes, which may be located on different pairs of homologous chromosome
each of these genes can have 2 or more alleles
all first generation offspring, will be heterozygous genotype
2
Q
how do you do a dihybrid cross for heterozygous genotypes (generation 2)?
A
3
Q
why do offspring sometimes differ from the expected ratio?
A
fertilisation of gametes= random process, in a small sample, a few chance events can cause a skewed ratio
the genes being studied are both on the same chromosome- known as linked genes, if no crossing over occurs the allele for the 2 characteristics will always be inherited together
