1. Chapter 5 Notes
Heredity

2. Section 5-1: Genetics genetics: the study of how traits are inherited
heredity: the passing of traits from a parent to an offspring
alleles: different forms of a trait that a gene may have
ex: AA, Aa, aa

3. Gregor Mendel: “The Father of Genetics” discovered that experiments he carried out on pea plants, provided an understanding of how traits are inherited
hybrid: an offspring that was given different genetic information for a trait from each parent
purebred: an offspring that was given similar genetic information for a trait from each parent

5. Dominant vs. Recessive
dominant: describes a trait that dominates another form of that trait
ex: tall, brown hair
recessive: describes a trait that is dominated by another form of that trait and seems to disappear
ex: short, red hair

6. Punnett Squares
punnett square: a tool used to predict the probability of certain traits in offspring that shows the different ways alleles (genes) can combine
ex: black lab x yellow lab
Bb x bb

7. Homozygous vs. Heterozygous
homozygous: an organism with two of the same alleles or genes
ex: BB, bb
heterozygous: an organism with two different alleles or genes
ex: Bb

8. Genotype vs. Phenotype
genotype: code for genetic make-up, types of genes
ex: BB, Bb, bb
phenotype: code for physical make-up, characteristics
ex: hair color, eye color

10. Section 5-2: Genetics Since Mendel
incomplete dominance: produces a phenotype that is in between the two homozygous pairs
ex: Red carnation x White carnation=Pink carnation
RR x R’R’ = RR’

11. multiple alleles: controls traits that require more than 2 alleles (genes)
ex: AO x BO (blood types)
Blood types: A, B, AB, O
Blood genotypes:
1. AB 4. BB
2. AA 5. BO
3. AO 6. OO

12. polygenic inheritance: occurs when a group of gene pairs acts together to produce a trait
ex: height, skin color, eye color

13. Types of Disorders 1. Chromosome disorders ex: Down’s Syndrome
2. Recessive Genetic Disorders
ex: Albinism
3. Sex-linked Disorders
ex: hemophilia, colorblindness

14. sex-linked gene: an allele inherited on a sex chromosome
ex: colorblindness, hemophilia

15. pedigree chart: shows the family history of genetic traits passed from one generation to the next

16. Section 5-3: Advances in Genetics
genetic engineering: experimenting with biological and chemical methods to change the arrangement of DNA that makes up a gene
Types of Genetic Engineering:
1. Recombinant DNA
2. Gene Therapy
3. Genetically Engineered Plants