Replication DNA will duplicate itself by separating the two strands and pairing new bases to the old strands This process is called semi-conservative because the new DNA is made of one strand that was “old” and one new strand

Protein Synthesis 1.Transcription – DNA unwinds – mRNA base pairs with DNA – mRNA moves out of nucleus 2. Translation – Ribosome attaches to mRNA – tRNA, that contains an amino acid (anticodon), base pairs with mRNA strand (codon). Amino acids are linked together. – Stop codon reached and amino acid sequence is released to fold (protein)

Mutations During either of these processes, the copying of the DNA can result in mistakes (mutations) Types of Mutations Point – one base is changed Substitution – one letter replaces another Insertion – one letter is added Deletion – one letter is removed

Biotechnology Genes can be manipulated through several techniques: – PCR: one copy of DNA is made into many copies – DNA can be cut using restriction enzymes and inserted into a new cell – Gel Electrophoresis: cutting DNA with restriction enzymes and separating the DNA based on size – Cloning: using DNA from an organism and inserting it into a new cell and promoting growth

Punnett Squares Dihybrid Crosses: two traits are examined and how they are passed to offspring Steps (for unlinked traits): – Write the cross – Write all possible gamete combinations – Use gamete combinations to create Punnett square

In horses, black is dependent upon a dominant gene, B, and chestnut upon its recessive allele, b. The trotting gait is due to a dominant gene, T, the pacing gait to its recessive allele, t. If a heterozygous black pacer is mated to a chestnut trotter (heterozygous), what will be the appearance of the F1 generation?

Linked Traits Some dihybrid crosses will have traits that are linked, meaning the alleles do not separate from each other. For Example: If someone has the genotype BbTt and the traits are linked, instead of having four gamete combinations, now there are only two: BT, and bt

Let's say Mr. and Mrs. Smiley both have the genotype EeTt. That means they are both hybrids, BUT the dominant alleles are linked. What are the possible outcomes for offspring?

Punnett Squares Sex-Linked Traits: show how a trait is passed on that is linked to an X or Y chromosome Steps: – Show cross using XX for females, XY for males – Use exponents for the particular trait – Create Punnett square to see outcomes

Hemophilia is a recessive sex-linked disease carried on the X chromosome in humans. A woman who is a carrier for hemophilia marries a man with hemophilia. Could any of their children have hemophilia? If so, would the child be male or female?

Punnett Squares Co-dominance: When the heterozygous individual has a both the dominant and recessive trait – Example: A white and red spotted flower Incomplete Dominance: When the heterozygous individual has a blending of the dominant and recessive trait – Example: A pink flower

A pink-flowered plant is crossed with a white- flowered plant. What is the probability of producing a pink-flowered plant?

In some chickens, the gene for feather color is controlled by co- dominance. The allele for black is B and the allele for white is W. The heterozygous phenotype is known as erminette. A black chicken and a white chicken are crossed. What is the probability that they will have erminette chicks?

Pedigrees A pedigree is a diagram of family relationships that uses symbols to represent people and lines to represent genetic relationships A pedigree can also help determine how a trait is passed on through generations

What are the genotypes of the individuals if this pedigree is showing how tongue rolling (a recessive trait) was passed through a family?

Chi-Square