Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.
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Transcript of Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.
![Page 1: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/1.jpg)
Chapter 14 – Mendel and the Gene Idea
![Page 2: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/2.jpg)
Gregor Mendel
• Mid 19th century Austrian monk
![Page 3: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/3.jpg)
Garden pea
• Self fertilize or cross fertilize
• True breeding or hybrids
![Page 4: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/4.jpg)
Garden pea traits
![Page 5: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/5.jpg)
Experimental design – monohybrid cross
![Page 6: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/6.jpg)
Terminology • “factors” = genes
– Alleles
• Dominant
• Recessive
![Page 7: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/7.jpg)
Terminology cont
• Phenotype
• Genotype – Homozygous
– Heterozygous
![Page 8: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/8.jpg)
Interpretation of monohybrid cross
• Law of Segregation
![Page 9: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/9.jpg)
Testcross
• To determine genotype of dominant individual
![Page 10: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/10.jpg)
Experimental design – dihybrid cross
• Law of independent assortment
![Page 11: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/11.jpg)
Extensions of Mendelian inheritance
• All of Mendel’s traits were coded for by a single gene and had only two alleles – with one being completely dominant over the other
• Not all traits are that simple
![Page 12: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/12.jpg)
Incomplete dominance
• Heterozygote has an intermediate phenotype
![Page 13: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/13.jpg)
Epistasis
• One gene masks the effects of another gene
![Page 14: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/14.jpg)
Environmental effects
• Phenotype is affected by environmental influence of gene expression
![Page 15: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/15.jpg)
Multiple alleles & Codominance
• Some genes have more than two alleles present in a population
• Codominance – heterozygote expresses both alleles
![Page 16: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/16.jpg)
Blood type cont
• Rh factor – Mendelian inheritance
• “+” completely dominant over “-”
– Erythroblastosis fetalis
![Page 17: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/17.jpg)
Polygenic inheritance
• Continous traits
![Page 18: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/18.jpg)
Pleiotropy
• One gene having multiple effects
![Page 19: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/19.jpg)
Pedigree analysis
![Page 20: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/20.jpg)
Recessive – albinism Dominant – Achondroplasia
![Page 21: Chapter 14 – Mendel and the Gene Idea. Gregor Mendel Mid 19 th century Austrian monk.](https://reader033.fdocuments.us/reader033/viewer/2022051114/56649f065503460f94c1b9b7/html5/thumbnails/21.jpg)
Prenatal testing