The genotype of F1 individuals in a tetrahybrid cross is AaBbCcDd. Assuming independent assortment of these four genes, what are the probabilities that F2 offspring will have the following genotypes?

(a) aabbccdd

(b) AaBbCcDd

(c) AABBCCDD

(d) AaBBccDd

(e) AaBBCCdd

When researchers compared gene expression in normal breast cells and cells from breast cancers, they found that the genes showing the most significant differences in expression encoded signal receptors. Explain why this result is not surprising.

Match the terms with the definitions. Some terms may not be used.

a. codicil

b. estate

c. estate tax

d. gift tax

e. inheritance $\operatorname{tax}$

f. power of attorney

g. probate

h. reverse mortgage

i. trust

j. will

__ A federal tax on property transferred from an estate to its heirs

In some bird species, the female chooses a mate that is most similar to her in size. This supports a. the good genes hypothesis.b. the runaway hypothesis.c. the sexual dimorphism hypothesis.d. All of these hypotheses could be true.e. None of these hypotheses are true.

Two diploid species of closely related frogs, which we will call species A and species B, were analyzed with regard to genes that encode an enzyme called hexokinase. Species A has two distinct copies of this gene: $A 1$ and $A 2$. In other words, this diploid species is A1A1 A2A2. The other species has three copies of the hexokinase gene, which we will call $B 1, B 2$, and $B 3$. A diploid individual of species $\mathrm{B}$ would be $B 1 B 1 B 2 B 2 B 3 B 3$. These hexokinase genes from the two species were subjected to DNA sequencing, and the percentage of sequence identity was compared among these genes. The results are shown here:

$$\begin{aligned} &\text { Percentage of DNA Sequence Identity }\\ &\begin{array}{rrrrrr} & A 1 & A 2 & B 1 & B 2 & B 3 \\ \hline A 1 & 100 & 62 & 54 & 94 & 53 \\ \text { A2 } & 62 & 100 & 91 & 49 & 92 \\ \text { B1 } & 54 & 91 & 100 & 67 & 90 \\ \text { B2 } & 94 & 49 & 67 & 100 & 64 \\ \text { B3 } & 53 & 92 & 90 & 64 & 100 \end{array} \end{aligned}$$

If we assume that hexokinase genes were never lost in the evolution of these frog species, how many distinct hexokinase genes do you think there were in the most recent ancestor that preceded the divergence of these two species? Explain your answer. Also explain why species $B$ has three distinct copies of this gene, whereas species A has only two.

A eukaryotic donor gene is likely to be expressed in a prokaryotic host organism if (a) the donor gene is a promoter gene (b) the donor gene is transferred along with the genes that turn it on $(c)$ the donor gene is placed beside a gene that is not expressed (d) all of these.

The model of globin gene evolution suggests that an ancestral gene duplicated and mutated to become $\alpha$ - and $\beta$-globin genes, and then each one was further duplicated and mutated. What features of the data set support the model?

The genes encoding the red- and green-color-detecting proteins of the human eye are located next to one another on the X chromosome and probably evolved from a common ancestral pigment gene. The two proteins demonstrate 76 percent homology in their amino acid sequences. A normal-visioned woman (with both genes present on each of her two X chromosomes) has a red color-blind son who was shown to have one copy of the green-detecting gene and no copies of the red-detecting gene. Devise an explanation for these observations at the chromosomal level (involving meiosis).

A spadefoot toad tadpole that develops in a rapidly drying pond is likely to eat many of its brothers and sisters. How can eating its siblings, which share half of an individual's genes, be favored by natural selection?

When Mendel conducted his famous hybridization experiments, he used peas with green pods and yellow pods. One experiment involved crossing peas in such a way that 25% (or 145) of the 580 offspring peas were expected to have yellow pods. Instead of getting 145 peas with yellow pods, he obtained 152. Assume that Mendel’s 25% rate is correct. Is there strong evidence to suggest that Mendel’s rate of 25% is incorrect?

A DNA library is a. an orderly array of all the genes within an organism. b. a collection of vectors. c. the collection of plasmids found within a single E. coli. d. a collection of DNA fragments representing the entire genome of an organism.

A pink-flowering plant is of genotype RW. If two such plants are crossed, we obtain a red plant (RR) with probability .25, a pink plant (RW or WR) with probability .50, and a white plant (WW) with probability .25, as shown in the table. What is the expected number of W genes present in a crossing of this type?

$$\begin{matrix} \text{Number of W Genes Present} & \text{}\\ \text{}{x_{i}} & \text{}{p_{i}}\\ \text{0} & \text{.25}\\ \text{1} & \text{.50}\\ \text{2} & \text{.25}\\ \end{matrix}$$

With two pairs of genes involved ( $P / p$ and $Z / z)$, a testcross (ppzz) with an organism of unknown genotype indicated that the gametes produced were in the following proportions:

$$P Z, 42.4 \% ; P_z, 6.9 \% ; p Z, 7.1 \% ; p z, 43.6 \%$$

Draw all possible conclusions from these data.

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?