<span>The correct answer is b. will have a one-quarter chance of being a sickle-cell-free homozygote.</span> <span>Sickle-cell disease is an autosomal recessive disease, which means that <span>if two individuals who are heterozygous for the sickle-cell disease have child, there is a 25% chance of sickle-cell disease, 25% that the child will not carry any sickle-cell alleles, and 50% that it will have the heterozygous condition (will have an allele for disease).</span></span>
The sporophyte generation of a moss dependent on the gametophyte generation is that it is used for support and most of its nutrients.A sporophyte is the diploid multicellular stage in the life cycle of a plant or alga and it<span> develops from the zygote produced.</span>
Crossing over – often, the sister homologous chromosomes of a cell exchange genetic material through recombination of genes.
Independent assortment/random fertilization – there are numerous variety of ways that the chromosomes of the gametes can combine, after meiosis, through fertilization to form a zygote
Mutation – on rare occasion, there is a slight and random change in the genes of a gametic cell caused by environmental factors.
