In a dihybrid cross,when $F_1$ plants $(RrYy)$ are self-hybridized,what is the segregation ratio of yellow and green seeds in the $F_2$ generation?

Which one of the following crosses will have a $1:1:1:1$ ratio of progeny?

In Mendel's dihybrid cross,what percentage of the $F_2$ generation possesses the $RrYy$ genotype (in $,\%$)?

Which genotype represents a true dihybrid condition?

In Mendel's dihybrid cross,the number of genotypes and phenotypes obtained in the $F_2$ generation are $P$ and $Q$ respectively. Identify $P$ and $Q$.

In humans, brown eyes $(B)$ are dominant over blue $(b)$ and dark hair $(D)$ are dominant over red hair $(d)$. A man with brown eyes and red hair marries a woman with blue eyes and dark hair. They have two children; one resembles the man (brown eyes, red hair), and the other resembles the woman (blue eyes, dark hair). What are the genotypes of the man and the woman?