In genetic crosses, the observed phenotypic ratios obtained in the offspring are often not the same as the expected ratios.

Suggest two reasons why.

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In tomato plants, the genes for height and for the type of leaf are on the same homologous pair of chromosomes. The allele T, for a tall plant, is dominant to the allele t, for a dwarf plant. The allele M, for normal leaves, is dominant to the allele m, for mottled leaves.

A biologist carried out crosses between parent plants heterozygous for both genes and examined the offspring produced. The position of the two alleles for both genes was the same in each parent plant as shown in Figure 7. The phenotypes and number of offspring produced are shown in Table 3.

What would be the genotype of the offspring with dwarf plants and mottled leaves?

Use the information provided to explain the results in Table 3.

Complete Table 4 to show the expected ratio of phenotypes if the same cross had been carried out but the genes for height of plant and for the type of leaf were on different homologous pairs of chromosomes.