Describe two types of DNA mutations Homework: Study for Final Exam!!! EOC Review Questions Due 6/1 (Friday)

DNA to Protein Video https://youtu.be/gG7uCskUOrA

DNA Structure DNA is double stranded and stores genetic information Made of nucleotides Deoxyribose sugar Phosphate group Nitrogenous base (Adenine, thymine, guanine, cytosine) Bases are held together by hydrogen bonds A binds with T, G binds with C

Transcription 1st step of protein synthesis (making proteins) Transcription takes DNA and makes mRNA DNA: A, T, G, C mRNA: A, U, G, C RNA is single stranded and made of ribose sugar mRNA is a messenger that can leave the nucleus

Translation 2nd step of protein synthesis mRNA leaves the nucleus and binds with a ribosome The mRNA is read three letters at a time (codon) Each three letters codes for the appropriate tRNA strand to bind which is carrying the correct amino acids Amino acids are chained together by peptide bonds to make a protein This occurs in the cytoplasm on a ribosome

Prokaryotes vs. Eukaryotes Bacteria, cell wall, flagella, NO nucleus Transcription and translation both occur in the cytoplasm Eukaryotes Plants, animals, fungi, protists Nucleus, some have cell wall Transcription occurs in nucleus, translation occurs in cytoplasm ALL CELLS HAVE: cell membrane, DNA, ribosomes

Mutations Point mutation: one nucleotide is substituted for another Ex: Sickle cell Frameshift mutation: one (or more) nucleotide is added or deleted Ex: Huntington’s Disease Frameshift mutations cause the entire chain of letters to shift, changing every codon after the mutation Usually more harmful than point mutations

Meiosis The process of making egg and sperm cells (gametes, sex cells) The number of chromosomes is cut in half through TWO rounds of cell division This way, the egg and the sperm each carry 23 chromosomes so the zygote gets the proper number (46). Increases genetic variation through crossing over and independent assortment

Genetics Dominant- Trait that shows up, even with just 1 allele (T) Recessive- the trait that is masked by the dominant (t) Homozygous- Two of the same alleles (tt or TT) Heterozygous- Two different alleles (Tt) Genotype- The genetic make up (i.e. the letters like TT or tt) Phenotype- physical characteristics

Complex Genetics Co-dominance- when TWO traits show up as dominant Ex: Roan cattle Incomplete Dominance- When neither is completely dominant, so the heterozygous is a blending of traits Ex: white X red flower = pink flowers Multiple Alleles- traits controlled by more than 2 alleles Ex: blood types: A, B, and O