Drosophila Mutations Such as Bcd, If Homozygous in the Mother

question 34

Multiple Choice

Drosophila mutations such as bcd, if homozygous in the mother, produce offspring with lethal defects, no matter what the genotype of the offspring. For some other genes, the mutant phenotype can be "rescued" by introducing a wild-type allele. What is the reason for these different outcomes?

• A)Non-rescuable mutations are of paternal origin.
• B)Rescuable mutations act as dominants.
• C)bcd is a maternal effect mutation.
• D)Rescue requires recombination between the maternal and introduced alleles.
• E)bcd is a Hox gene.

---

Definitions:

Lower Explosion Limit (LEL)

The lowest concentration of a particular gas or vapor in air that can produce a flash of fire in presence of an ignition source.

Propagate

To reproduce, spread, or increase in number, often used in the context of plants (via seeds or cuttings) and ideas or information.

Upper Explosion Limit (UEL)

The highest concentration of vapor in air above which propagation of flame does not occur on contact with a source of ignition.

Thermobaric Bomb

A type of explosive weapon that uses oxygen from the surrounding air to generate a high-temperature explosion, producing a blast wave of significant duration.