Discussion:
Phenotypic and genotypic ratios
Solve all of these problems using a Punnett Square. If you cannot reproduce the square using software, then you may do them by hand and scan in the image of your solution and submit all images in the one document.
In summer squash, white fruit color (W) is dominant over yellow fruit color (w). If a squash plant homozygous for white is crossed with a plant homozygous for yellow, what will the phenotypic and genotypic ratios be for:
the F1 generation?
the F2 generation?
Suppose that you purchased a well-shaped white summer squash plant and wished to use its seeds in a breeding experiment. However, you do not know its genotype. Describe a breeding experiment (referred to as a testcross) that you could carry out to determine the genotype of your white squash? (Hint: a testcross is usually performed between a known genotype and an unknown genotype.)
In roses, red petal colour is dominant over white. Use R for the red gene. Use r for the white gene. If we cross two heterozygous red roses, use a Punnett square to describe the phenotypes and genotypes of the offspring.
In certain trees, smooth bark (use A) is dominant over wrinkled (use a). If you cross two trees that are heterozygous for smooth bark and there are 100 offspring produced, use the Punnett square to predict how many will have wrinkled bark?