The Science of Animal Agriculture Ch. 4 The Science of Genetics.
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Transcript of The Science of Animal Agriculture Ch. 4 The Science of Genetics.
![Page 1: The Science of Animal Agriculture Ch. 4 The Science of Genetics.](https://reader035.fdocuments.net/reader035/viewer/2022072017/56649f085503460f94c1d4db/html5/thumbnails/1.jpg)
The Science of Animal Agriculture
Ch. 4
The Science of Genetics
![Page 2: The Science of Animal Agriculture Ch. 4 The Science of Genetics.](https://reader035.fdocuments.net/reader035/viewer/2022072017/56649f085503460f94c1d4db/html5/thumbnails/2.jpg)
Genetic Basics
• Gregor Mendel (1822-1884)– first person to develop workable theory
• transfer of traits
– used garden peas
– based on purebred strains
![Page 3: The Science of Animal Agriculture Ch. 4 The Science of Genetics.](https://reader035.fdocuments.net/reader035/viewer/2022072017/56649f085503460f94c1d4db/html5/thumbnails/3.jpg)
Law of Dominance
• overriding or dominant factors make certain recessive traits disappear
![Page 4: The Science of Animal Agriculture Ch. 4 The Science of Genetics.](https://reader035.fdocuments.net/reader035/viewer/2022072017/56649f085503460f94c1d4db/html5/thumbnails/4.jpg)
Law of Segregation
• the alleles responsible for the traits from each parent are separated and then combined with factors from the other parent at fertilization
![Page 5: The Science of Animal Agriculture Ch. 4 The Science of Genetics.](https://reader035.fdocuments.net/reader035/viewer/2022072017/56649f085503460f94c1d4db/html5/thumbnails/5.jpg)
Law of Independent Assortment
• Factors for certain characteristics are passed from parents to the next generation separate from the other factors or genes that transmit other traits
![Page 6: The Science of Animal Agriculture Ch. 4 The Science of Genetics.](https://reader035.fdocuments.net/reader035/viewer/2022072017/56649f085503460f94c1d4db/html5/thumbnails/6.jpg)
Punnett Square
• Developed by R.C. Punnett
• illustrates the possible combinations for a particular trait
RRR
R
rrrr
Rr
Rr
Rr
Rr
![Page 7: The Science of Animal Agriculture Ch. 4 The Science of Genetics.](https://reader035.fdocuments.net/reader035/viewer/2022072017/56649f085503460f94c1d4db/html5/thumbnails/7.jpg)
Punnett Square
• Developed by R.C. Punnett
• illustrates the possible combinations for a particular trait
RrR
r
RrrR
RR
Rr
Rr
rr
![Page 8: The Science of Animal Agriculture Ch. 4 The Science of Genetics.](https://reader035.fdocuments.net/reader035/viewer/2022072017/56649f085503460f94c1d4db/html5/thumbnails/8.jpg)
Genetics Basics
• genes are in chromosomes– different animals have different chromosome
#’s• cattle = 30 pairs• horses = 32 pairs• apples = 34 pairs
• each allele contains two genes– one by each parent
![Page 9: The Science of Animal Agriculture Ch. 4 The Science of Genetics.](https://reader035.fdocuments.net/reader035/viewer/2022072017/56649f085503460f94c1d4db/html5/thumbnails/9.jpg)
Selective Breeding
• the choosing of individuals of a single strain and species
• artificial selection
• need to avoid inbreeding
![Page 10: The Science of Animal Agriculture Ch. 4 The Science of Genetics.](https://reader035.fdocuments.net/reader035/viewer/2022072017/56649f085503460f94c1d4db/html5/thumbnails/10.jpg)
Hybridization
• the crossing of different species
• hybrid vigor– the ability of hybrids or strain crosses to
exceed the parents in performance
• most hybrids are sterile
![Page 11: The Science of Animal Agriculture Ch. 4 The Science of Genetics.](https://reader035.fdocuments.net/reader035/viewer/2022072017/56649f085503460f94c1d4db/html5/thumbnails/11.jpg)
Crossbreeding
• the mating of unrelated strains of the same species to avoid inbreeding