Page 10 20. In the fruit fly Drosophila melanogaster the gene for eye colour is sex-linked. The allele for red eye (R) is dominant to the allele for white eye (r). A cross between two flies produced the offspring shown in the table below. Sex of offspring Number with white eyes Number with red eyes female 23 22 male 21 22 The genotypes of the parents in this cross were A XrXr and XRY B XRXr and XrY C XRXr and XRY D XRXR and XrY. 21. Which row in the table best describes r-selected species? Number of offspring Offspring survival rate Parental care A many low little B few high extensive C many high extensive D few low little