AAMC 5 Biology - Genetics

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Feb 25, 2012
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In a mating of 2 strains that are homozygous in their macronuclei and heterozygous in their micronuclei for a recessive gene, what percentage of the F1 generation will express the recessive phenotype?"

A) 0
B) 25
C) 50
D) 100

The answer was "B"
I do not understand where in the passage that states macronuclei are not accounted for in meiosis. Maybe I'm missing an obvious detail.
Where from the passage could we assume we could ignore the homozygous macronuclei?


On a side note on a different passage, why isn't Benzylamine aromatic?


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The macronucleus is described as "amitotic". On the other hand, the micronucleus is described as "germ-line" that implies it gives rise to gametes. At the end of the process, the micronucleus is clearly replicated as each daughter cell gets a whole copy of the micronucleus, but just a portion of the macronucleus.
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Their reasoning is correct. It's just a matter of semantics. I would have missed that question, too.
The overall structure has aromaticity. But its a primary, not aromatic, amine. If an aromatic ring was attached directly to nitrogen then it would be an aromatic amine.