Question

1. Complete a Punnett square representing the mating between a purple- flowered pea plant (Pp) and a white-flowered pea plant (pp). (6 pts) 2. What is the phenotypic ratio of the potential offspring? (2 pts) 3. What is the genotypic ratio of the potential offspring? (2 pts)

Answer 1

The genotype of a purple flowered pea plant is represented by Pp.

The genotype of a white flowered pea plant is represented by pp.

This mating represents a monohybrid cross. A single trait, that is pea flower colour is being examined. The dominant allele is purple represented by P and the recessive allele is white represented by p. Thus, a Punnette square representing this cross is as follows.

This gives us a list of the allelic combinations of the potential offspring of this cross which is 2 Pp and 2 pp.

Since P is the dominant allele, Pp will give purple flowered pea plant. Since p is recessive and in pp there is no dominant allele, pp will give white flowered pea plant.

The phenotypic ratio of the potential offspring is purple : white :: 1:1 which means that 50% of the offspring will give purple colored flowers and 50% will give white colored flowers.

The genotypic ratio of the potential offspring is Pp:pp :: 1:1, which means that 50% of the offspring will have the genotype Pp and 50% will have pp.

Second Page -

Q1. The precancerous cells are similar to cancer cells and these do not spread and remain at the original site. Even Benign tumors are cells that remain at the original site but these are not cancerous.

Q2. On the other hand, metastatic cancer cells spread to other parts of the body.

Q3, The process is called metastasis.

Q4. Sex chromosomes or allosomes determine an individual's sex.

Q5. Autosomes are any chromosomes other than those from Q4.