Biol 105 Final Lab Exam IVY Tech with 100- correct answers (graded A+)

Biol 105 Final Lab Exam IVY Tech with 100- correct answers (graded A+) G1 phase - ANSWER -metabolic activities, building up and breaking down macro molecules, this also the phase that initiates mitosis S phase - ANSWER -The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated. Centromere - ANSWER -Region of a chromosome where the two sister chromatids attach G2 phase - ANSWER -Growth and preparation for cell division M-phase - ANSWER -The phase of the cell cycle that includes mitosis and cytokinesis. crossing over - ANSWER -exchange of genetic material between homologous chromosomes during prophase I of meiosis synapsis - ANSWER -the fusion of chromosome pairs at the start of meiosis. Heterozygous - ANSWER -An organism that has two different alleles for a trait Homozygous - ANSWER -An organism that has two identical alleles for a trait Dominant - ANSWER -An allele that is always expressed Recessive - ANSWER -An allele that is masked when a dominant allele is present Trait - ANSWER -A characteristic that an organism can pass on to its offspring through its genes. Phenotype - ANSWER -An organism's physical appearance, or visible traits. Genotype - ANSWER -An organism's genetic makeup, or allele combinations. Allele - ANSWER -Different forms of a gene Gene - ANSWER -A segment of DNA on a chromosome that codes for a specific trait spontaneous generation - ANSWER -the mistaken idea that living things can arise from nonliving sources Biogenesis - ANSWER -the production of living organisms from other living organisms normal flora - ANSWER -bacteria which are found in or on our bodies on a semi-permanent basis without causing disease nutrient broth - ANSWER -commonly used liquid complex medium for culture growth Agar - ANSWER -solidifying agent for nutrient broth fastidious - ANSWER -Will not grown well in unsupplemented broth or agar heat fixing - ANSWER -kills the bacteria, makes them adhere to the slide, and coagulates cytoplasmic proteins to make them more visible Gram-positive bacteria - ANSWER -Bacteria that have a thick peptido glycan cell wall, and no outer membrane. They stain very darkly (purple) in Gram stain. Gram-negative bacteria - ANSWER -Bacteria that have a thin peptidoglycan cell wall covered by an outer plasma membrane. They stain very lightly (pink) in Gram stain. Gram-negative bacteria are typically more resistant to antibiotics than Gram-positive bacteria. What is the primary stain in gram staining ? - ANSWER -crystal violet Gram's iodine does what? - ANSWER -It is a mordant meaning it helps the stain attach to the cell better. What is the purpose of the ethanol in gram staining? - ANSWER -It is a decolorizing agent. In Gram negative cells the thinner layer of peptidogylcan has larger pores to allow for alcohol to penetrate and remove the aggregated crystal violet. The color remains in the Gram positive. The ethanol What is the secondary stain in gram staining? - ANSWER -Safranin which is trapped in the thin layer or peptidogylcan