[Campbell Biology P.7] According to Figure 17.1 and its caption, what is the most accurate... | Practice Question
According to Figure 17.1 and its caption, what is the most accurate description of the genetic basis of albinism in the Asinara donkeys?
A: Albinism is caused by a dominant mutation that enhances pigment synthesis, and inbreeding has led to a decrease in its prevalence.
B: The albinism is due to a recessive mutation that disables pigment synthesis, and inbreeding on the island has increased the number of homozygous albino donkeys.
C: The mutation affects mRNA directly, preventing the transcription of the pigment gene, resulting in albinism.
D: Albinism results from an environmental factor, not a genetic mutation, affecting pigment production.
Explanation
Figure 17.1's caption directly states: 'a recessive mutation that disables pigment synthesis arose in the DNA of one donkey and was passed down through the generations. Inbreeding has resulted in a large number of homozygous albino donkeys living on the island today.' This information directly supports option B.