Mutations in DNA Gene Expression Protein Synthesis DNA Patterns of Inheritance

Who was Gregor Mendel and what was his model? Priest who studied traits in pea plants; model is that traits are passed from parent to offspring; traits can sometimes be different.

What are Mendel’s laws of inheritance? Law of Segregation- only receive one allele from each parent; Law of Independent Assortment- alleles assort independently of one another if on different chromosomes

Why are Mendelian genetics hard to analyze? Polygenes, incomplete dominance, codominance. epistasis, pleiotropic effects, environmental effects

What are Punnett squares and what are they used for? Punnett squares are diagrams used to visualize the probable outcome of a particular genetic cross.

What is aneuploidy? When the chromosome number is not the typical number for that species. Ex: one extra or one less

Who were the two scientists credited for finding the double helix? Watson & Crick

Describe the structure of DNA Composed of nucleotides (5 C sugar, phosphate and nitrogen base). Alternating sugar and phosphate make up the backbone; nitrogen bases make up interior by base pairing.

What is the law of base pairing in DNA? A-T and C-G

Describe the DNA replication process 1.DNA helicase attaches to helix and begins to unwind it. Double helix “unzips” down the middle. SSB’s proteins attach to stabilize strands. 2.RNA primer is added 3.DNA poly III add nucleotides in the 5 / to 3 / direction 4.DNA poly I removes primer and fills in missing nucleotides 5.DNA ligase fills in gaps left by Okazaki fragments

Why was the work of Beadle & Tatum, Sanger and Ingram important? Began to unravel the mystery of what DNA does…..holds instructions for production of proteins.

What is the structure and function of RNA? It is composed of nucleotides; single stranded; mRNA reads DNA code and takes it from nucleus to ribosome, tRNA transfer amino acids to ribosome; rRNA major constituent or ribosomes.

Define codon and anticodon Codon- set of 3 nucleotides on an mRNA molecule Anticodon- set of 3 nucleotides on a tRNA molecule

Discuss transcription RNA polymerase unwinds the target gene, DNA strands separate, complimentary base pairs of mRNA are added in the 5 / to 3 / direction until a stop sequence is reached.

Discuss translation mRNA leaves nucleus and attaches to a ribosome (P site), tRNA brings amino acid to ribosome (AUG), this exposes the adjacent codon (A site), tRNA brings second a.a. to ribosome; amino acids bond; complex moves to E site ejecting first tRNA and exposing A site again. Process continues until stop codon is reached.

What three modifications are made to primary transcripts? 1.Introns are removed, exons spliced together 2.5 / cap 3.Poly-A tail

Discuss the trp operon Cluster of five genes to manufacture tryptophan; if tryptophan is present in environment, repressor binds to the operator shutting off the gene

Discuss the lac operon Operon that possess two regulatory sites. The activator switch and the repressor switch. Helps cell produce what it needs only when it needs it.

Why is gene control essential to all organisms? In bacteria, it allows the cells to take advantage of the changing environment and in multicellular organisms, it is critical for development and homeostasis

What are enhancers? Distant sites where regulatory proteins bind in eukaryotic cells.

How can eukaryotes regulate genes after transcription? 1.Processing of primary transcript 2.Selecting which transcripts leave the nucleus 3.Selecting which transcripts are translated

Discuss different types of mutations 1.Point- single base substitution 2.Frame-shift- addition or deletion of a base 3.Inversion- chromosome or portion is flipped in the wrong direction 4.Translocation- a piece of one chromosome breaks off and switches location with another.

Define benign and malignant tumors Benign- reproduction of essentially normal cells Malignant- reproduction of cancer cells

What is metastases? The spreading for cancer cells from one location to another in the body.

How is cancer related to the cell cycle? The cell cycle has checkpoints to ensure process is occurring accurately. If checkpoints are not followed, cells could divide out of control.

What is genetic recombination? Combining two or more genomes for a desired result.