HONR 1034 Chapter Notes - Chapter 10: Frederick Griffith, Streptococcus Pneumoniae, Dnainfo.Com

What is a genome? What is a genome made of? Describe the bacterial genome. How do bacteria reproduce? What is binary fission? Distinguish between a chromosome and chromatin. Where are chromosomes located in eukaryotic cells? What is the chromosome made of? What is a centromere? What is the centromere's role? What are sister chromatids and how do they arise? Distinguish between somatic cells and germ (gametes) cells. Describe the cell cycle. What are the different phases? What occurs during S phase? What is interphase? How is the cell cycle controlled?

Describe mitosis. What are the phases of mitosis? What occurs in each of the phases of mitosis? What is cytokinesis? How does this differ between plant and animal cells? What is a kinetochore? Where does it form? What is its role? What is the role of microtubules in mitosis? What is a centriole and what is it composed of? What is a centrosome and what is its role in mitosis? What is the metaphase plate and why is this important? What is the mitotic spindle, its role and its makeup? What defines a diploid cell? How many copies of each chromosome is in a diploid cell? What about a haploid cell? Why do the daughter cells of mitosis always have the same complement of chromosomes?

Describe meiosis. What are the phases of meiosis? What occurs in each of the phases of meiosis? Distinguish between meiosis I and meiosis II and describe how each of these processes compare to mitosis. Why do animal cells undergo meiosis? What is a gamete? What is a zygote? What are recombination, crossing-over, and chiasma? When and why does this occur? What is meant by 'homologous pair of chromosomes'? Why don't the daughter cells of meiosis have the same genetic makeup? What controls the segregation of chromosomes into the gametes?

What are genetic characters? What are genetic traits? What is an allele? What is a locus? How many alleles at each locus would a human cell have and why? Distinguish between genotype and phenotype. What is meant by a dominant gene? What is meant by a recessive gene? How do these differ? What is the genotype of a homozygous dominant organism? What is its phenotype? What is the genotype of a homozygous recessive organism? What is its phenotype? What is the genotype of a heterozygous organism? What is its phenotype? What is a genetic cross? Distinguish between the P, F1, and F2 generations. What is a true-breeding line? What is the genotype and phenotype of a cross between homozygous dominant and homozygous recessive parents? If the F1 progeny are crossed, what would be the genotype and phenotype of the F2 generation? What would be the phenotypic ratio? What would be the genotypic ratio? Be ready to generate Punnet square tests or probability analyses of crosses involving more than one genetic locus. Describe a dihybrid cross where two alleles are homozygous dominant in one parent and homozygous recessive in the other. What would be the phenotypic ratio of the F2 generation from this dihybrid cross? What is meant by independent assortment? Be prepared to calculate probabilities resulting from different crosses.

Distinguish between complete and incomplete dominance. How would incomplete dominance alter the results of a hybrid cross? What would the resulting F2 generation phenotype and genotype ratios be? What is codominance? How does this affect the results of crosses? Be prepared to determine likely blood types of parents based on the blood types of their offspring. What is a polygenic trait? What is a carrier state for a genetic disease? What is meant by linked genes? How does this affect expected outcomes of genetic crosses? How is gene linkage used for chromosomal mapping? Distinguish between autosomes and sex chromosomes. What sex chromosomes are found in women? What sex chromosomes are found in men? What are sex-linked traits? Be prepared to give the results of crosses that involve sex-linked recessive traits. What is the process of nondisjunction? What are the likely results? Why is this important? What is a Barr body? Recognize the genetic abnormality of Downs Syndrome, Turner's Syndrome, and Klinefelter's Syndrome.

Scientists have been studying the effects of Starkagaren Disease, which is regulated by the stgn gene, in cultured normal and breast cancer cell lines. They have fused a yellow fluorescent probe to the end of the stgn gene to study the disease more closely. By adding a probe, it will create a hybrid protein that emits a yellow color under a blue laser. This hybrid protein is known as a fluorescent –tagged protein, meaning that the protein itself will function and fold normally but it will be tagged with a yellow fluorescent probe (YFP) at the end. This allows the scientists to follow the protein through the cell cycle. They find that the Stgn protein normally binds to centromeres in normal cells. After looking at cells at various stages of the cell cycle, they find that compared to normal cells, the breast cancer cells that express the Starkagaren Disease display abnormal nuclei, some appear very large, some have tiny nuclei, and some cells do not have a nucleus at all.

Scientists found out that Starkagaren Disease is passed on through a mutation in the germ cells. The mutation is found on the chromosome 12 so either the mother or father can pass on the gene. But in order for the disease to express, both parents need to have the mutation. You are a genetic counselor talking to two individuals that have familial history of either a grandparent or aunt or uncle with the disease, they would like you to explain their chances of having a child that could possible inherit the disease.

Scientists have been studying the effects of Starkagaren Disease, which is regulated by the stgn gene, in cultured normal and breast cancer cell lines. They have fused a yellow fluorescent probe to the end of the stgn gene to study the disease more closely. By adding a probe, it will create a hybrid protein that emits a yellow color under a blue laser. This hybrid protein is known as a fluorescent–tagged protein, meaning that the protein itself will function and fold normally but it will be tagged with a yellow fluorescent probe (YFP) at the end. This allows the scientists to follow the protein through the cell cycle. They find that the stgn protein normally binds to centromeres in normal cells. After looking at cells at various stages of the cell cycle, they find that compared to normal cells, the breast cancer cells that express the Starkagaren Disease display abnormal nuclei, some appear very large, some have tiny nuclei, and some cells do not have a nucleus at all.

Scientists have figured out that Starkagaren Disease is passed on through a mutation in the germ cells. The mutation is found on the chromosome 12 so either the mother or father can pass on the gene. But in order for the disease to express, both parents need to have the mutation. You are a genetic counselor talking to two individuals that have familial history of either a grandparent or aunt or uncle with the disease, they would like you to explain their chances of having a child that could possible inherit the disease.

a) Would the defect be found in homologous chromosomes or sister chromatids, or both? Explain.

b) If the location of the gene with the defect is found near the tip of the chromosome, how likely would that defect transfer to a homologous chromosome? Explain how it may or may no occur.