In Drosophila, the Genes Y, F, and V Are All

question 36

Multiple Choice

In Drosophila, the genes y, f, and v are all X-linked. Females who are homozygous for recessive alleles of all three genes (y f v / y f v) are crossed to wild-type males. The resulting trihybrid F1 females are testcrossed. The F2 are distributed as follows:

$$\begin{array} { | l | r | } \hline y f v & 3210 \\\hline y f v ^ { + } & 72 \\\hline y f ^ { + } v & 1024 \\\hline y f ^ { + } v^ + & 678 \\\hline y ^ { + } f v & 690 \\\hline y ^ { + } f v ^+ & 1044 \\\hline y ^ { + } f ^+ v & 60 \\\hline y ^ { + } f ^+ v^ + & 3222 \\\hline & 10,000 \\\hline\end{array}$$

-Which of the following linkage maps correctly shows the order and distance between the y, f, and v genes?

• A)f--35 m.u.--y--15 m.u.--v
• B)f--22 m.u.--y--15 m.u.--v
• C)y--35 m.u.--f--22 m.u.--v
• D)y--22 m.u.--v--15 m.u.--f
• E)y--15 m.u.--v--22 m.u.--f

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Definitions:

Alcohol Consumption

The intake of beverages containing ethanol, which can have various effects on health and behavior depending on the amount and frequency of use.

Independent Variables

Factors in an experiment that are intentionally manipulated to observe their effect on dependent variables.

Dependent Variables

Variables in an experiment that are expected to change as a result of manipulations in the independent variables.

Confounding Variables

Factors other than the independent variable that may cause a change in the dependent variable, potentially skewing results in an experiment.