The cross of a heterozygous fly with a homozygous fly can be shown as follows:
r r
R Rr Rr
r rr rr
The results show that there is a 50% probability that the flies produced will have red eyes. Their genotypes will be heterozygous.
The results of the punnet square show that there will be a 50% probability that the offsprings will have brown eyes. Their genotype will be homozygous recessive.
A homozygous trait can be described as a trait which has same alleles for the gene which encodes the trait. Heterozygous means that both the alleles for the trait will be different.
Answer: The vulnerable embryo must be sheltered from desiccation and other environmental hazards. In both seedless and seed plants, the female gametophyte provides protection and nutrients to the embryo as it develops into the new generation of sporophyte.