Final answer:
Crossing a bicoid-null female with a wild type male in Drosophila leads to embryos with abnormal development, whereas a cross between a red-eyed female and a white-eyed male results in red-eyed F1 offspring due to X-linked inheritance patterns.
Step-by-step explanation:
Phenotypes Resulting from Crosses in Drosophila
When a bicoid-null female Drosophila is crossed with a wild type male Drosophila, the resulting embryo phenotype can be predicted based on Mendelian genetics and the understanding of Drosophila development. The bicoid gene is crucial for the early development of fruit flies and is a maternal effect gene, meaning the phenotype of the offspring is determined by the genotype of the mother. Because the bicoid-null females lack the functional product required for the proper head and thorax formation, embryos from this cross would show abnormal development, typically lacking the structures that would form from the anterior part of the embryo.
In studying the genetics of eye color in Drosophila - a well-known X-linked trait - we can utilize the information provided by past genetic crosses. A cross between a homozygous red-eyed female (XWXW) and a white-eyed male (XY) would result in all red-eyed F1 progeny, with the males being hemizygous for the red allele (XWY) and females being heterozygous carriers (XWXw). Mendelian laws and the concept of X-linkage provide the necessary framework to predict the outcomes of these types of genetic crosses accurately.