{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

05-Linkage-1 - Non-Mendelian Genetics segregation of linked...

Info icon This preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
Non-Mendelian Genetics segregation of linked alleles crossing over linkage in Drosophila two-point mapping in Drosophila three-point mapping in maize interference
Image of page 1

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

View Full Document Right Arrow Icon
Gamete formation when two heterozygous gene pairs are on different chromosomes: Mendel’s independent assortment Two metaphase 1 tetrads Four different types of gametes AaBb
Image of page 2
Gamete formation when two heterozygous gene pairs are on the same chromosomes but no exchange of chromosomal segments occurs between them: linkage All gametes produced are noncrossover ( parental , P) One metaphase 1 tetrad Two types of gametes
Image of page 3

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

View Full Document Right Arrow Icon
Crossing over Crossing over is the exchange of chromosomal material between homologous chromosomes by breakage and reunion . occurs during prophase I of meiosis ( pachytene ) Result : parental gametes are still produced, but some non parental ( recombinant ) gametes are generated at a lower frequency
Image of page 4
Gamete formation when two heterozygous gene pairs are on the same chromosomes and exchange of chromosomal segments occurs: linkage and recombination Gametes produced: noncrossover ( parental , P) and crossover ( non parental , NP) Four different types of gametes
Image of page 5

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

View Full Document Right Arrow Icon
Single crossover event between two nonsister chromatids outside the area of the two genes: no recombination of alleles only parental gametes are produced result : two types of gametes
Image of page 6
parental and recombinant gametes are produced result : four types of gametes; parentals in higher proportion hypothetical limit for recombinant percentage: 50% Single crossover event between two nonsister chromatids in between the two genes: recombination of alleles
Image of page 7

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

View Full Document Right Arrow Icon
brown locus: bw + : red eye ( dominant ) bw : brown eye ( recessive mutant ) heavy wing vein locus: hv + : thin wing vein ( dominant ) hv : heavy wing vein ( recessive mutant ) Alleles in two autosomal Drosophila loci P 1 cross bwbw hv + hv + X bw + bw + hvhv
Image of page 8
F 1 gametes Complete linkage no recombination occurs •F 1 individuals can only produce parental gametes ( theoretical )
Image of page 9

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

View Full Document Right Arrow Icon
F 1 cross: bw + bw hv + hv X bw + bw hv + hv a non-Mendelian dihybrid cross
Image of page 10
Complete linkage Notice : in the P 1 generation, the parents were both homzygous dominant for one character and homozygous recessive for the other character •as a result, all the F 1 individuals were heterozygous for both
Image of page 11

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

View Full Document Right Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern