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Introduction to Genetics Ch. 11. Write the information on the slides that show this symbol or that is this color.

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Presentation on theme: "Introduction to Genetics Ch. 11. Write the information on the slides that show this symbol or that is this color."— Presentation transcript:

1 Introduction to Genetics Ch. 11

2 Write the information on the slides that show this symbol or that is this color.

3 Genetics The scientific study of heredity

4 Gregor Mendel Father of modern genetics Combined plant breeding, statistics, careful record keeping

5 Mendel studied pea plants traits (characteristics)

6 Genetic Information Gene – basic unit of genetic information Allele – one form of a gene

7 Principle of Dominance Some alleles are dominant and others are recessive

8 Dominant vs. Recessive Dominant alleles express a trait. (capital letter) Recessive alleles are only visible when paired with another recessive allele. (lower case letter)

9 Segregation Gamete Separation of alleles during gamete formation Sex cells

10 Punnett Square Diagram used to predict and compare variations resulting from a genetic cross

11 Homozygous vs. Heterozygous Homozygous - having two dominant or two recessive alleles. (BB or bb) Heterozygous - having both a dominant and recessive allele. (Bb)

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13 Genotypes Phenotypes Genotype - genetic make up Phenotype – physical characteristics

14 Genotypes Phenotypes (example) genotypes phenotypes

15 Hybrid Offspring of crosses between parents with different traits

16 Principle of Independent Assortment Genes for different traits can segregate independently during the formation of gametes. Example: genes for seed shape segregate independently of those for seed color

17 Incomplete Dominance One allele is not completely dominant over another

18 Incomplete Dominance A flower has genes for white petals (w) and red petals (r). When you mix white flowers with red flowers you get pink flowers. How is this possible? The w gene does not dominate over the r gene and vice versa. Both genes express themselves equally so you get a pink color in the petals. ww rwr r

19 Codominance Both alleles contribute to the phenotype

20 Polygenetic Traits Traits controlled by two or more genes

21 Meiosis reproduction of gametes (Similar to mitosis, but there are 2 divisions, ending with ½ the number of chromosomes of the parent cell.)

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23 Diploid vs. Haploid Diploid – contains both sets of homologous chromosomes Haploid – contains a single set of chromosomes

24 Crossing-over is the process in which homologous chromosomes exchange portions of their chromatids during meiosis.

25 Gene Map Diagram showing the relative locations of each known gene on a particular chromosome


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