Biology 30 questions (need help!)?

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anna

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Straight wings in flies are dominant over curly wings. Explain how you would determine whether a straight-winged fly is heterozygous or homozygous for this trait.

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In a species of plant, one variety produces a broad leaf and another variety produces a narrow leaf. When these varieties are crossed, all offspring have intermediate-sized leaves. What fraction of a cross between two of the F1 offspring would have intermediate sized leaves? What is the name given to this process of blending?

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Thank you in advance for all help! It is very much appreciated!!
 
1. Using a cross between the fly that you want to determine the genotype of and a curly-winged fly (which you know would be homozygous recessive, since only two recessive genes produce a recessive trait).

2. Two would. One would have broad leaves, and the other would have narrow leaves. The phenomenon of intermediate leaves is called 'incomplete dominance' and it is a result of both alleles having an effect on the phenotype (as opposed to complete dominance like in the first question, where the dominant allele completely overshadows the recessive one).
 
because straight wings is dominant over curly wings ...means one has to be homozygous and the other has to be recessive

assume AA= homozygous for straight wings
aa= curly wings

A A
a Aa Aa
a Aa Aa

how to determine ...when its dominant for the trait ., its simply saying its homozygous dominant AA ...

2 . Intermediate crosing
A a
A AA Aa
a Aa aa number of Aa= 2/4
=.5
 
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