Chapter 5 Notes Heredity

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

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

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

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

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

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

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’

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

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

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

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

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

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