In Drosophila, singed bristles [sn] and cut wings [ct] are both caused by recessive X-linked alleles. The wild type alleles [sn+ and ct+] are responsible fro straight bristles and intact wings, respectively. A female homozygous for sn and ct+ is crossed to a sn+ ct male. The F1 flies are interbred. The F2 males are distributed as follows:

sn ct 13
sn ct+ 36
sn+ ct 39
sn+ ct+ 12

What is the map distance bwteen sn and ct?

Which supports the idea that birds and butterflies both have wings but they do not have a common ancestor with wings? the wings are analogous structures that evolved differently and do not have a similar internal structure. the wings are homologous structures that evolved differently and do not have a similar internal structure. wings of birds are vestigial structures, but the wing structures of bats are not vestigial. wings of bats are vestigial structures, but the wing structures of birds are not vestigial.

Which best describes a rhinovirus? o a. a virus that causes a common cold o b. a protective shell around a virus o c. a tube the comes off a virus o d. a piece of dna transferred by a virus

Cedric has a low fever and minor aches. yesterday, he went to the doctor for his booster shot and receive the flu shot. which best explains why he has this reaction?