Lect 18 - Gene Linkage and Recombination Bio Sci 97 Lecture...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
©2003 C. Brachmann 1 Gene Linkage and Recombination Bio Sci 97 Lecture 18 Dr. Carrie Brachmann Department of Developmental and Cell Biology cbrachma@uci.edu Reading for lect 19: H&J Ch 4.1-4.3 Gist Ch 9 D &E
Background image of page 1

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

View Full DocumentRight Arrow Icon
©2003 C. Brachmann 2 Meiosis error leads to nondisjunction From “An Introduction to Genetic Analysis” W.H. Freeman and Company, publ Chromosomes fail to disjoin during Meiosis I 2 gametes have 2 copies of chrm 21 2 gametes have 0 copies of chrm 21 chrm 21 (dad) chrm 21 (mom) chrm 21 (dad) chrm 21 (mom) Chromosomes disjoin properly in Meiosis I BUT chromatids fail to disjoin in Meiosis II 2 normal gametes, 1 copy chrm 21 1 gamete with 2 copies chrm 21 1 gamete with 0 copies chrm 21
Background image of page 2
©2003 C. Brachmann 3 Problems 1. A flowering plant has 5 complete sets of chromosomes. Is this plant fertile? 1pt 1. A calico female cat mates with a black male cat. There are 3 female calico kittens in the litter. Is the calico pattern of each female identical to its sisters? Explain your answer. 1pt No Each kitten looks different. X-inactivation is random and will never be the same between individuals.
Background image of page 3

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

View Full DocumentRight Arrow Icon
©2003 C. Brachmann 4 3. Dogs, like humans are diploids, but they are clearly smarter (!) than humans because their chromosome complement is 78 chromosomes, compared to our measly 46 chromosomes. The XX genotype in dogs is female and the XY genotype is male. a. Is the dog genome aneuploid or euploid? Give the number of dog chromosomes that are found in each type of cell or are described by each term. a. Somatic cell b. Gamete c. Autosome d. monoploid number Euploid 78 39 76 39
Background image of page 4
5 A boy with Klinefelters syndrome (47XXY) is found to also have the X-linked recessive trait green hair (gr). Both the mother and father have normal colored hair. 3pts a. Give the genotypes of the mother, father and the son with Klinefelters. Be sure to include the recessive trait, green hair (gr). mom: dad: son: a. In whose genome did nondisjunction occur and at which meiosis (I or II or both or not determinable)? X
Background image of page 5

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

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 29

Lect 18 - Gene Linkage and Recombination Bio Sci 97 Lecture...

This preview shows document pages 1 - 6. Sign up to view the full document.

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