Pre AP Biology -GEN 5.2 Predicting Inheritance- FRQ Exam Style Questions -New Syllabus

(a)

• Mendel used a technique called artificial pollination (or manual cross-pollination).
• To perform this, he carefully opened the flower buds of the female parent plant before they matured.
• He removed the anthers (the male reproductive parts) to prevent the plant from self-pollinating. This process is known as emasculation.
• He then collected pollen from the anthers of a selected male parent plant.
• Finally, he dusted this pollen onto the stigma (the female reproductive part) of the emasculated flower to ensure cross-fertilization occurred.

(b)

• The two yellow pea plants from the first generation have a heterozygous genotype (Yg).
• This means they carry one dominant allele for yellow colour (Y) and one recessive allele for green colour (g).
• Even though their phenotype is yellow (because Y is dominant over g), they still carry the genetic information for green peas.
• During gamete formation, these alleles segregate, meaning each parent has a 50% chance of passing on the recessive g allele.
• If an offspring receives a recessive g allele from both parents, its genotype will be homozygous recessive (gg).
• Because there is no dominant yellow allele to mask it, this gg offspring will express the green phenotype.
• Therefore, two yellow parents can produce a green offspring due to the inheritance of recessive alleles from both sides.