3. Ch5_Oct_21_ - 1 What is the map distance between sn and...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 10/21/09 1 What is the map distance between sn and ct ? A. 15 m.u. B. 18 m.u. C. 33 m.u. D. 49 m.u. E. 67 m.u. In Drosophila , singed bristles ( sn ) & cut wings ( ct ) are both caused by recessive, X‐linked alleles. The wild‐type alleles ( sn + and ct + ) are responsible for straight bristles and intact wings, respecPvely. A female homozygous for sn and ct + is crossed to a sn + ct male. The F 1 flies are interbred. The F 2 males are distributed as follows: sn ct 15 sn ct + 34 sn + ct 33 sn + ct + 18 ¡hysical ¡roof of RecombinaPon • Barbara McClintock & Harriet Creighton, 1931 • Corn chromosomes with di¢erent morphologies • Must have some way of disPnguishing b/w the 2 homologues. • IdenP£able markers present at both ends of chromosome • CC & Cc = coloured; cc = colourless • WxWx & Wxwx = starchy endosperm; wxwx = waxy endosperm They look happy because they have corn chromosomes that they can physically disPnguish. Not covered in class; however you are responsible for this material 10/21/09 2 • CC & Cc = coloured; • cc = colourless • WxWx & Wxwx = starchy endosperm; • wxwx = waxy endosperm 1. 2a. 3. 2b. • From the progeny, we can infer the genotypes of the gametes produced by the individual with the 2 morphologically dis?nct chromosomes • Can then back up phenotypic observa?ons by looking at the chromosomes themselves; with recombinant phenotypes, saw recombinant chromosomes Linked Genes Happen to Autosomes too… • Parental types (combina¡ons) > recombinant types genes are LINKED • Parental allele combina¡ons transmifed together > 50% oF ¡me...
View Full Document

{[ snackBarMessage ]}

Page1 / 10

3. Ch5_Oct_21_ - 1 What is the map distance between sn and...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online