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.

What structure is responsible for forming the mitotic spindle during prophase?

What occurs during the latter stages of mitotic prophase except?

Consider two hypothetical recessive autosomal genes $a$ and $b$, where a heterozygote is a test crossed to a double homozygous mutant. Predict the phenotypic ratios under the following conditions:
(a) $a$ and $b$ are located on separate autosomes.
(b) $a$ and $b$ are linked on the same autosome but are so far apart that a crossover always occurs between them.
(c) $a$ and $b$ are linked on the same autosome but are so close together that a crossover almost never occurs.

In a cotransformation experiment (see solved problem S4), DNA was isolated from a donor strain that was pro $A^{+}$and $\operatorname{str} \mathrm{C}^{+}$and sensitive to tetracycline. (The proA and str $C$ genes confer the ability to synthesize proline and confer streptomycin resistance, respectively.) A recipient strain is a proA- and $\operatorname{str} \mathrm{C}^{-}$and is resistant to tetracycline. After transformation, the bacteria were first streaked on a medium containing proline, streptomycin, and tetracycline. Colonies were then restreaked on a medium containing streptomycin and tetracycline. (Note: Both types of media had carbon and nitrogen sources for growth.) The following results were obtained:
70 colonies grew on the medium containing proline, streptomycin, and tetracycline, but only 2 of these 70 colonies grew when restreaked on the medium containing streptomycin and tetracycline but lacking proline.
A. If we assume the average size of the DNA fragments is 2 minutes, how far apart are these two genes?
B. What would you expect the cotransformation frequency to be if the average size of the DNA fragments was 4 minutes and the two genes are $1.4$ minutes apart?

In a cotransduction experiment, the transfer of one gene is selected and the presence of the second gene is then determined. If 0 out of 1000 P1 transductants that carry the first gene also carry the second gene, what would you conclude about the minimum distance between the two genes?

If two bacterial genes are $0.6$ minutes apart on the bacterial chromosome, what frequency of cotransductants would you expect to observe in a P1 transduction experiment?

Identify the mistakes in the incorrect formulas and formula names, and design a flowchart to prevent the mistakes. copper acetate

Identify the mistakes in the incorrect formulas and formula names, and design a flowchart to prevent the mistakes. disodium oxide

Identify the mistakes in the incorrect formulas and formula names, and design a flowchart to prevent the mistakes. a. copper acetate b. $\mathrm{Mg}_{\mathrm{2}} \mathrm{O}_{3}$ c. $Pb _3 O _5$ d. disodium oxide e. $\mathrm{Mg}_{3}\left(\mathrm{PO}_{4}\right)_{2}$

Describe the function of each part of a seed.

A 4.5-g- nugget of pure gold absorbed 276 J of heat. The initial temperature was $25.0^{\circ} \mathrm{C}$. What was the final temperature?

A 50-cm-long spring is suspended from the ceiling. A 250 g mass is connected to the end and held at rest with the spring unstretched. The mass is released and falls, stretching the spring by 20 cm before coming to rest at its lowest point. It then continues to oscillate vertically. a. What is the spring constant? b. What is the amplitude of the oscillation? c. What is the frequency of the oscillation?

Which part of the seed grows and develops? Circle the correct answer. (a). seed coat (b). embryo