Assume That a and B Are Two Linked Genes on an Autosome

question 63

Multiple Choice

Assume that A and B are two linked genes on an autosome in Drosophila. A testcross is made where AB/ab flies are crossed to ab/ab flies and the progeny are counted and shown below. However, it is known that the Aa/bb genotype is lethal before the flies hatch and does not appear among the testcross progeny counted. What is the most precise map distance between the two genes that can be calculated from these data? Aa Bb = 235
Aa bb = 225
Aa Bb = 20

• A) 4.2 m.u.
• B) 4.0 m.u.
• C) 16.4 m.u.
• D) 8.0 m.u.
• E) 50 m.u.

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Definitions:

Repressed Memories

Memories unintentionally hidden from consciousness due to their connection with significant trauma or stress.

Memory Malleability

The concept that human memory is not static and can be influenced or changed by various factors, including suggestion, misinformation, and misattribution.

Retroactive Interference

A phenomenon in cognitive psychology where new information interferes with the ability to recall old information.

Proactive Interference

A phenomenon where older memories interfere with the recall of newer memories.