1. The correct answer is: all of the above.
When Mendel designed his experiment he choose a model system that makes it easy for a researcher to investigate and to physically control. He studied the inheritance of seven different features in pea lines, each with two different forms (e.g. tall vs. short). The pea lines were pure-breeding (offspring identical to the parent), he crossed them and observed how the traits were inherited.
2. The correct answer is: D. It is more of an advantage to the purple flower to be homozygous dominant.
The dominant form of a flower color (in this case purple) could mask the presence of the recessive form (blue). So, when both alleles are present in the genotype (Pp) only the dominant will be expressed (blue color will be expressed only when there are two alleles for its color-pp). pp is homozygous for the blue and PP is homozygous genotype for the purple color.
3. The correct answer is: D. Law of Segregation, because individuals have two forms for each trait and they must separate during the formation of eggs and sperm.
Each gene of an organism comes in two different forms - alleles. A dominant allele which can mask the presence of a recessive allele. Both of them together determine the organism's appearance (phenotype). When an organism makes gametes (during the meiosis), each gamete receives just one gene copy (one allele), selected randomly and that is the Law of segregation discovered by Mendel.
4. The correct answer is: C. Dimples are a dominant trait.
If Jesi has a Dd genotype, which is heterozygous and expresses dimples, this means that the allele D is dominant (d is recessive) and “responsible” for the formation of dimples. Tom has dd genotype, which is recessive homozygous and doesn’t express dimples.
5. The correct answer is: A. The recessive trait reappeared about 25% of the time.
Offspring of the first parental generation (P generation, pure-breed) are called F1 generation or first filial generation. Mendel let the F1 self-fertilize naturally and then collected and grew the seeds from them. That was the F2 generation. As a result, ¾ of F2 generation were those with dominant trait (e.g. tall plants) and ¼ were recessive ones (e.g. short plants).
