Just for fun, imagine that "shirt-striping" is a phenotypic character caused by a single gene. Construct a genetic explanation for the appearance of the family in the above photograph, consistent with their "shirt phenotypes." Include in your answer the presumed allele combinations for "shirt-striping" in each family member. Identify the inheritance pattern shown by the child.

Model building can be an important part of the scientific process. The illustration here is a computer generated model of a DNA replication complex. The parental and newly synthesized DNA strands are color-coded differently, as are each of the following three proteins: DNA pol III, the sliding clamp, and single-strand binding protein. Using what you've learned to clarify this model, label each DNA strand and each protein.

You are handed a mystery pea plant with tall stems and axial flowers and asked to determine its genotype as quickly as possible. You know that the allele for tall stems (7) is dominant to that for dwarf stems (t) and that the allele for axial flowers (A) is dominant to that for terminal flowers (a). Identify ALL the possible genotypes for your mystery plant.

A wild-type fruit fly (heterozygous for gray body color and normal wings) is mated with a black fly with vestigial wings. The offspring have the following phenotypic distribution: wild-type, 778; black vestigial, 785; black-normal, 158; grayvestigial, 162. What is the recombination frequency between these genes for body color and wing size? Is this consistent with the results of the experiment with a recombination frequency of 17%?

The continuity of life is based on heritable information in the form of DNA. In a short essay (100-150 words), explain how the passage of genes from parents to offspring, in the form of particular alleles, ensures perpetuation of parental traits in offspring and, at the same time, genetic variation among offspring. Use genetic terms in your explanation.

Two pea plants heterozygous for the characters of pod color and pod shape are crossed. Draw a Punnett square to determine the phenotypic ratios of the offspring.

Determine what the problem is asking. If asked to do a cross, write it out in the form [genotype] x [genotype], using the alleles you've decided on.

The pedigree traces the inheritance of alkaptonuria, a biochemical disorder. Affected individuals, indicated here by the colored circles and squares, are unable to metabolize a substance called alkapton, which colors the urine and stains body tissues. Does alkaptonuria appear to be caused by a dominant allele or by a recessive allele? Fill in the genotypes of the individuals whose genotypes can be deduced. What genotypes are possible for each of the other individuals?

Density-dependent inhibition is explained by which of the following?

a) As cells become more numerous, the amount of required growth factors and nutrients per cell becomes insufficient to allow cell growth.

b) As cells become more numerous, the protein kinase they produce begin to compete with each other, such that proteins produced by one cell essentially cancel those produced by its neighbour.

c) As cells become more numerous, more and more of them enter the S phase of the cell cycle.

d) As cells become more numerous, the level of waste products increases, eventually slowing down metabolism.

e) As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce control factors.

The pedigree below traces the inheritance of alkaptonuria, a biochemical disorder. Affected individuals, indicated here by the colored circles and squares, are unable to metabolize a substance called alkapton, which colors the urine and stains body tissues. Does alkaptonuria appear to be caused by a dominant allele or by a recessive allele? Fill in the genotypes of the individuals whose genotypes can be deduced. What genotypes are possible for each of the other individuals?

A histogram is a bar graph that shows the distribution of numeric data (here, the number of dark-skin alleles). To make a histogram of the allele distribution, put skin color (as the number of dark-skin alleles) along the $x$-axis and the predicted number of offspring (out of $64$) with each phenotype on the $y$-axis. There are no gaps in these allele data, so draw the bars next to each other with no space in between.

When aqueous KI is added gradually to mercury(II) nitrate, an orange precipitate forms. Continued addition of KI causes the precipitate to dissolve. Write balanced equations to explain these observations. $(Hint: Hg^{2+}$ reacts with $\mathrm { I } ^ { - }$ to form $\mathrm { Hg } \mathrm { I } _ { 4 } ^ { 2 - }.)$

Two circles that have one point in common are tangent circles. Given any triangle, explain how to draw three circles that are centered at each vertex of the triangle and are tangent to each other.

Work the following applied problem.

Bill Poole wants to have $20,000 available in 5 years for a down payment on a house. He has inherited$16,000. How much of the inheritance should he invest now to accumulate the $20,000 if he can get an interest rate of 5.5% compounded quarterly?