Lab 2 FINAL PDF

MEIOSIS: Meiosis (4 haploid cells non-identical) ▪​ Requires two nuclear divisions ▪​ Chromosomes synapse and cross over ▪​ Centromeres Survive Anaphase I ▪​ Halves chromosome number ▪​ Produces four daughter nuclei ▪​ Produces daughter cells genetically diff...

MEIOSIS: Meiosis (4 haploid cells non-identical) ▪​ Requires two nuclear divisions ▪​ Chromosomes synapse and cross over ▪​ Centromeres Survive Anaphase I ▪​ Halves chromosome number ▪​ Produces four daughter nuclei ▪​ Produces daughter cells genetically different from the parent and each other ▪​ Used only for sexual reproduction MITOSIS: DIPLOID ▪​ Requires one nuclear division ▪​ Chromosomes do not synapse nor cross over ▪​ Centromeres dissolve in mitotic anaphase ▪​ Preserves chromosome number ▪​ Produces two daughter nuclei ▪​ Produces daughter cells genetically identical to the parent and each other ▪​ Used for asexual reproduction and growth ​ Stem Cells ▪​ mammalian organs ​ Retain ability to divide ​ Red bone marrow ​ produce various types of blood cells  ▪​ Therapeutic cloning = produce human tissues (adult or embryonic stem cells) ▪​ Embryonic stem cells (reproductive cloning) CELL CYCLE AND CHECKPOINTS: Interphase ▪​ Cell performs usual functions ▪​ Time varies by cell type ▪​ Interphase consists of: G1, S, & G2 phases G1 checkpoint Cell cycle main checkpoint. Mitosis checkpoint. Mitosis will occur if DNA has replicated properly. Apoptosis will occur if the DNA is damaged and cannot be repaired. Mitosis checkpoint. G2 checkpoint Mitosis will occur if DNA has replicated properly. Apoptosis will occur if the DNA is damaged and cannot be repaired. If DNA is damaged M checkpoint Spindle assembly checkpoint. Mitosis will not continue if chromosomes are not properly aligned.  ​ M (Mitotic) Stage ▪​ http://www.viddler.com/embed/ffe7e7f ▪​ http://www.viddler.com/embed/7f895890 ▪​Includes: ​Mitosis –​ Nuclear division –​ Daughter chromosomes are distributed by mitotic spindle to 2 daughter nuclei ​Cytokinesis –​ Division of cytoplasm ▪​Results in 2 genetically identical daughter cells ​ Incomplete Dominance: ▪​ Heterozygote, phenotype intermediate between either homozygote ​ Homozygous red = red phenotype ​ Homozygous white = white phenotype ▪​ Phenotype reveals genotype without a test cross ▪​ A dihybrid cross uses true-breeding plants differing in two traits ▪​Multiple alleles occur when there are more than two versions of a gene, or alleles, for a trait in a population ▪​ Each trait is controlled by two alleles  ▪​ Dominant allele masks expression of recessive allele ▪​ Alleles occur on a homologous pair of chromosomes at a particular gene locus ​ Homozygous = identical alleles ​ Heterozygous = different alleles ▪​ Used “true-breeding” (homozygous) plants ▪​ Chose varieties that differed in only 1 trait (monohybrid cross) ▪​ A monohybrid cross is defined as the cross happening in the F1 generation offspring of parents differing in one trait only ​ Codominance is a genetic phenomenon where two versions of a gene (alleles) are expressed equally, resulting in the appearance of both traits ​ Sex Linkage: Traits influenced by the sex chromosomes influenced by X or Y LAB SETUP Introduction: Discuss the problem/topic,Why is it important?, State Hypothesis, A statement, not a question,Describe your procedures Methods: Detailed/“Repeatable”Paragraph form, NO outline Written in past tense Avoid words like I, He, She, Results: Strictly results, statistics, graphs, tables NO explanations Need at least 1 graph, 1 table labeled,Paragraph format, P-value Discussion: Accept or reject hypothesisCan’t prove a hypothesisIf rejected, provide alternative,If results did not come out as expected, what happened? Explain your results Literature Cited:  ​ What are antibiotics? Antibiotics (e. g. penicillin, streptomycin) are natural or synthetic molecules that stop the growth and survival of bacteria. They act by inhibiting enzymes in metabolic pathways, cell wall synthesis, protein synthesis, or DNA synthesis. Which one(s) did we test? ampicillin. What is B-lactam? How do B-lactam antibiotics work? They work by inhibiting the bacteria and covalently bonding to Pencilin Binding Proteins ​ Why are β-lactamases important? β-lactamases are enzymes produced by bacteria that deactivate β-lactam antibiotics. ​ β-lactamases break a bond in the β-lactam ring found in β-lactam antibiotics, rendering the antibiotic nonfunctional. What genes are we looking for in our soil samples? BLA 1, BLA-TEM, Bla SHV How to properly label an agar plate? Label around the edge of the bottom (not the lid) of an agar plate with at least your name, the date, the type of growth medium, and the type of organism to be plated on the medium ​ What were the steps of extracting soil samples from campus? We use a sterile container and make it closed until you’re ready to collect. Then remove the lid and scoop up the sample with the lip of the container. While scooping up an inch of soil. How do you properly plate the bacteria? ​ How did we extract bacteria from agar plates? We extracted bacteria  from agar plates by breaking up the soil sample, using the tongue depressor, then adding twice the amount of distilled water, closing the cap tight, and suspending the soil in water, so that it becomes particles. Let it sit until two layers start forming. Then remove the lid and transfer 100 microliters of supernatant to the LB+ AMP plate. Use the yellow rod to spread the water evenly over the surface of the plate then let it stand upright and invert the places and put them into Tupperware they will be incubated. How was the “soil smoothie” made? The Soil smoothie was made by mixing distilled water and soil. ​ How to properly use a micropipette? Set the micropipette to the correct volume, by adjusting the dial, Place a clean tip over the micropipette, Press the plunger down and hold it down while having the tip beneath the liquid surface, and release the plunger to let the sample get into the pipette tip. Then deliver the sample by pressing the plunger to the first stop, then depress the plunger at the second stop to release any sample. Discard by pressing the ejector button. What is DNA Isolation & how is it done? DNA Isolation is a technique to remove cellular proteins, and RNA leaving the DNA by itself. ​ What is in the master mix? A master mix is a mixture containing precursors and enzymes used as an ingredient in polymerase chain reaction techniques in molecular biology. Such mixtures contain a mixture dNTPs (required as a substrate for the building of new DNA strands), MgCl2, Taq polymerase (an enzyme required to buildnew DNA strands), a pH buffer and come mixed in nuclease-free water. ​ Why do we specifically use Taq DNA polymerase? How does it work? We use the Taq DNA polymerase because of it’s ability to be heat resistant. It works by applying it to PCR applications and when an enzyme has double stranded region, the polymerase will kick out the nontemplate strand. ​ What is PCR? What does each step involve? Polymerase Chain Reaction,  Each step involves, double stranded dna going through the Denaturing stage, the Annealing Stage: Annealing of primers from the OG strand for a new strand synthesis, and Extending Stage: Extension of new DNA strands from primers. What is a PCR machine? A machine designed to replicate DNA, detecting DNA, DNA fingerprinting, forensic analysising, detecting pathogens. ​ How to load samples into gel electrophoresis wells. We load the samples into gel electrophoresis wells by loading meth blue dye into p20 micropipette, brace the wrist and position the tip of micropipette onto the wells, depress plunger and push sample out, should drop into pipette tip into to the bottom of the well, while doing this you must keep plunger depressed. ​ What is Gel Electrophoresis and how does it work? A technique separating dna fragments according to molecular size, It works by using an electric current to push DNA through the gel. ​ What is a DNA Ladder? Why have controls? A DNA ladder is used to determine the size of different dna molecules that got separated in the electrical field in the gel. ​ How do we interpret the gel electrophoresis results? By checking for bands, by comparing them and making sure it’s the right size. Thinner bands means there’s proteins present. If you get a band that’s the correct size then it has a certain resistance gene. ​ All precautions taken to keep sterile environments? ​ What enzymes were involved in the experiment? What do they do? B-Lactamase, breaks the antibiotic ring, which causes them to deactivate. Hunter Rose Did the work +10000000 aura ​ What is antibiotic resistance? How does it work? Antibiotic resistance is when a bacteria builds up resistance to an antibiotic drug. This happens when a bacteria has a change in its genes that allows it to build a resistance to the antibiotic. ​ What is the purpose of a control? If this is referring to a control group then the purpose is so that scientists can experiment on one group and still have the control group to reflect back on and see what  changes/lack of changes occur. ​ All Questions from lab handout are fair game