4 Genetics - types of inheritance (by Lizzy)
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The document defines key genetic terms like genotype, phenotype, dominant and recessive alleles. It describes different inheritance patterns such as dominant-recessive, sex-linked, and codominance. As an example of codominance, it explains ABO blood groups which have three alleles - IA, IB, and i - where IA and IB are codominant so people can have blood type A, B, or AB if they contain both alleles.
4 Genetics - types of inheritance (by Lizzy)
- 1. Types of Inheritance Lizzy Kim Tuesday, 22 November 11 1
- 2. Assessment Statements 4.3.1: Define genotype, phenotype, dominant allele, recessive allele, codominant alleles, locus, homozygous, heterozygous, carrier and test cross 4.3.4: Describe ABO blood groups as an example of codominance and multiple alleles 4.3.5-10 Tuesday, 22 November 11 2
- 3. Basic definitions Genotype: the alleles of an organism phenotype: the characteristics of an organism Dominant allele: an allele that has the same effect on the phenotype whether it is present in the homozygous or heterozygous state Recessive allele: an allele that only has an effect on the phenotype when present in the homozygous state Tuesday, 22 November 11 3
- 4. Dominant - Recessive Phenotype of dominant alleles will show when one or more allele is dominant For recessive characters to show, both alleles must be recessive Tuesday, 22 November 11 4
- 5. Sex-linked Some characteristics are linked on to the sex chromosomes Mostly, X chromosomes carry specific alleles There could be sex-linked dominant and recessive characteristics Hemophiliac and color-blindness are the commonly used examples of sex-linked characteristics Tuesday, 22 November 11 5
- 6. Codominant There are two types of alleles at once Both characters are shown when both dominant alleles are present Cows: When both black and white alleles are shown they could be dotted Flowers: When both red and white alleles are shown they could be pink Tuesday, 22 November 11 6
- 7. As: 4.3.4 Describe ABO blood groups as an example of codominance and multiple alleles There are three types of alleles: I^A, I^B, i A and B alleles are dominant, i allele is recessive (represents blood type O) Tuesday, 22 November 11 7
- 8. THANK YOU TYPES OF INHERIT- ANCE FYI, THEY ARE CODOMINANT! DATE CREATOR 11.22.2011 LIZZY KIM Tuesday, 22 November 11 8