Construct a genetic diagram to predict the offspring genotypes and phenotypes when the cat in Fig. 5.1 is crossed with a cat heterozygous for the hair length gene and heterozygous for the coat pattern gene. Include: parent phenotypes; parent genotypes; gametes; $F_1$ genotypes; $F_1$ phenotypes.
Scientists isolated two DNA segments believed to correspond to the allele for full colour ($R$) and the allele for pointed ($r$). Sequencing of these two segments showed that the DNA sequence for full colour, $R$, contained a restriction site for the restriction enzyme $Hpa\text{II}$. That restriction site was absent from the DNA sequence $r$ because a single nucleotide substitution had occurred. The scientists next analysed three generations of cats. Each cat was examined for three characteristics: • coat pattern, full colour or pointed • whether the $Hpa\text{II}$ restriction site was present or absent • the pair of alleles at a variable marker locus thought to be close to the $R/r$ locus. The marker locus has seven different alleles labelled $1, 2, 3, 4, 5, 6,$ and $7$. Fig. 5.2 presents the pedigree of these cats and the outcomes of the assessment.
Use evidence from Fig. 5.2 to support the claim that the pointed phenotype is caused by a recessive allele.
Use evidence from Fig. 5.2 to support the statement that the $R/r$ gene lies on an autosome.
Use evidence from Fig. 5.2 to support the statement that the marker locus and $R/r$ are closely linked.