Biology Chapters 8-11 Mendel, DNA, Portiens, Genes

Discovery of Heredity Mechanism Gregor Mendel is the “Father” of genetics Genetics is the study of how traits are transmitted from one generation to the next Mendel studied pea plant traits Punnett squares are used to determine the probable outcome of genetic crosses Blood type alleles can be used to predict offspring Blood Types (A, B, AB, O)

Chromosomes and Genes In living organisms Chromosmes come in pairs and genes for a trait come in pairs An allele is a form of a gene (example: T or t) An allele for a recessive trait is lower case (t) An allele for a dominant trait is capital (T) A dominant allele masks the effects of a recessive allel example: Ff is a person with freckles

Phenotype and Genotype Alleles that are the same are called homologous Alleles that are different are called heterozygous Phenotype is the appearance of a trait (black…) Genotype is the genetic makeup (Ff….) Examples: Bb is heterozygous for black fur Examples: FF is homozygous dominant for freckles

DNA DNA is made of long chains of nucleotides Nucleotides have 3 parts There are 4 different DNA nucleotides (A,T,G,C) DNA makes DNA (cell replication) DNA makes RNA (transcription of the DNA code) RNA makes Proteins (translation of the DNA code) therefore: DNA directs protein manufacturing

Genetic Engineering Genetic engineering is the Insertion of genes from one species into another species Human genes can be inserted into bacteria so the bacteria can make human proteins Genetic engineering is used to make plants resistant to destructive insects (GMO) Dairy cows produce more milk when genetically engineered growth hormones are put in their food

Blood Type There are 4 different Blood Types possible in people (A, AB, B, O) There are 3 alleles for the blood type gene (a, b, i) Genes are paired in people so they have only 2 alleles Example: AA = blood type A, AB = blood type AB, Ai = blood type A, ii = blood type O, Bi = type blood type B Question: if Mom is AB and Dad is Ai can they have a child that is blood type O ? A? B? AB?