Suppose you discovered a new mutation in mice that causes a curved spine. You noticed that this mutant phenotype is present only in females. When curved-spine females are crossed with normal males, the progeny are always recovered in a 1:1:1 ratio of curved-spine females, normal females, and normal males. Explain the genetic basis for this ratio.
A) hemizygous or homozygous lethal autosomal allele
B) hemizygous or homozygous lethal sex-linked allele
C) recessive sex-linked allele
D) recessive autosomal allele
E) dominant sex-linked allele
B) hemizygous or homozygous lethal sex-linked allele
You might also like to view...
The high variability of the types of G protein-coupled receptors allows for:
A. different types of cells to respond to different types of signals. B. different types of signal-transduction pathways to respond to signals. C. a rapid response to cell signals. D. a sensitive response to cell signals. E. All of these choices are correct.
A strain that can grow in a minimal medium containing arginine, but NOT in minimal media containing citrulline nor in minimal media containing ornithine would have a mutation in the gene that encodes for _____.
Wild type bread mold can grow in a minimal medium without supplements, while certain mutated strains can only grow in a minimal medium that is supplemented with specific intermediates. See the figure below for an overview of the arginine biosynthetic pathway.
A. enzyme 1.
B. enzyme 2.
C. enzyme 3.
D. both enzymes 1 and 3.
E. both enzymes 2 and 3.
Which of the following did Mendel confirm with reciprocal crosses that generated an identical F 1 and F 2 offspring ratio of 3:1?
a. Traits are inherited independently. b. Dominant and recessive traits are blended. c. Recessive traits disappear at every cross. d. First-generation crosses produce hybrids.
Ethanol is an inhibitor of ADH. Therefore, a person
consuming a mixed drink excretes a. less water because ADH promotes reabsorption. b. the alcohol because ADH cannot degrade it. c. ketone bodies formed from the alcohol. d. more water because ADH normally promotes reabsorption. e. more water plus the alcohol due to the ADH inhibition.