[Campbell Biology P.511] According to the results presented for both Experiment 1 and Experi... | Practice Question
According to the results presented for both Experiment 1 and Experiment 2, how do the phenotypic effects of FOXP2 disruption differ between heterozygous and homozygous mice?
A: Homozygous mice showed severe brain abnormalities and complete absence of vocalization, while heterozygous mice had less severe brain effects and only a slight reduction in vocalization.
B: Both homozygous and heterozygous mice exhibited severe brain abnormalities and a complete absence of vocalization, with no significant difference between the two genotypes.
C: Homozygous mice displayed complete absence of vocalization but no brain abnormalities, whereas heterozygous mice showed severe brain abnormalities but normal vocalization.
D: Homozygous mice had severe brain abnormalities and complete absence of vocalization, and heterozygous mice also showed extreme effects on vocalization and less severe but still present brain abnormalities.
Explanation
Experiment 1 results state that disruption of both FOXP2 copies homozygous led to disorganized brain cells, and effects on heterozygotes were less severe. Experiment 2 results show that disruption of both copies led to an absence of vocalization homozygous , and the effect on vocalization in heterozygotes was 'extreme.' Option D accurately combines these findings, showing that homozygous mice have severe effects in both aspects, while heterozygous mice have less severe brain abnormalities but still extreme vocalization issues.