Two Haploid Yeast Cells,one Wild Type and One Having a Mutation

question 15

Essay

Two haploid yeast cells,one wild type and one having a mutation blocking the synthesis of adenine,were mated to produce a diploid zygote.Through asexual reproduction (mitosis),this zygote gave rise to hundreds of identical cells,and all were wild type in phenotype.These (diploid)cells were then induced to undergo meiosis,and the progeny (a random sample of haploid meiotic products)consisted of 214 cells able to grow without adenine and 203 unable to grow without adenine.
a)Diagram the cross,picturing the chromosomes of the parents,the zygote,metaphase I,and the meiotic products.
b)How many genes are involved?
c)What are the dominance relationships of the alleles of the gene or genes?

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Definitions:

Increased Pressure

A condition where the force exerted by a fluid against a surface is higher than normal.

Pupillary Light Reflex

A reflex that controls the diameter of the pupil in response to the intensity of light to protect the retina by constricting or dilating the pupil.

Penlight

A small, portable flashlight, often used in medical examinations to observe pupils' reaction to light or to inspect areas of the mouth and throat.

Pupillary Constriction

The narrowing or tightening of the pupils, which can occur in response to light exposure or during focusing on objects.