genetics review 1.docx

1. [How can Mendel's law of inheritance be observed in meiosis 1 and 2? And discuss the Mechanisms that increase genetic variation for cells]? Mendel\'s law of inheritance, specifically the \"Law of Segregation\" is directly observed during Meiosis 1, where homologous chromosomes se...

1. [How can Mendel's law of inheritance be observed in meiosis 1 and 2? And discuss the Mechanisms that increase genetic variation for cells]? Mendel\'s law of inheritance, specifically the \"Law of Segregation\" is directly observed during Meiosis 1, where homologous chromosomes separate, ensuring each gamete receives only one allele for a particular gene, while the \"Law of Independent Assortment\" is seen in the random alignment of different chromosome pairs during Metaphase 1, allowing for independent segregation of alleles from different genes; both processes contribute to the genetic diversity observed in offspring. 2. Hox genes are a family of transcription factors that help regulate physical development in a multitude of animals. a. [If a scientist removes a gene in Drosophila, resulting in a different Morphology, what is this an example of?] homeotic transformation b. [In mice removal of the hoxA3 gene (expressed in the neck vertebrae region. Has no effect on the development of this region Why might this be possible?] functional redundancy with other Hox genes 3. [What are the three mechanisms by which heterozygotes have an increased fitness via overdominance? Describe?] 1. Functional complementation (different alleles providing different functions), 2. Improved protein function due to allelic diversity, and 3. Resistance to multiple pathogens due to diverse immune response; essentially, the heterozygous state allows for a broader range of phenotypic expression, often leading to greater adaptability compared to homozygotes. 4. [Discuss the four levels of complexity of nucleic acids?] primary structure (nucleotide sequence), secondary structure (local folding patterns), tertiary structure (3D conformation), and quaternary structure (interactions between multiple nucleic acid molecules or with proteins) 5. [Compare and contrast prokaryotic and eukaryotic chromosomes?] prokaryotic chromosomes are simpler and smaller, with a single circular structure, while eukaryotic chromosomes are complex, linear, and organized with histone proteins within the nucleus. 6. [A gene that codes for tail length has recessive allele that leads to decreased tail lengths in heterozygous cats and is lethal when homozygous (recessive). If two cats with decreased tail length mate, what will be the genotypic and phenotypic frequencies of their offspring.] 7. [What are the four criteria that must be met by genetic material?] stability, ability to replicate accurately, capacity for expression when needed, and transmission from parent to offspring without significant change. 8. [Compare and contrast meiosis 1 and meiosis 2]. Meiosis 1 separates homologous chromosomes, reducing the chromosome number by half, while meiosis 2 separates sister chromatids within each daughter cell, resulting in four haploid gametes 9. [What mechanisms are utilized by eukaryotes.] Transcriptional control, Rna processing, Alternative Splicing, Epigenetic modifications, chromatin structure, Cell Division. 10. [Define a gene a locus and an allele? How are these related to the genotype, phenotype and karyotype of an organism?] A gene is a specific sequence of DNA on a chromosome that codes for a particular trait, a locus is the fixed position on a chromosome where a specific gene is located, and an allele is one of the different versions of a gene that can exist at a given locus; essentially, different variations of the same gene, with the combination of alleles at a locus determining an organism\'s genotype, which in turn influences its observable characteristics or phenotype; a karyotype represents the complete set of chromosomes in an organism, including the arrangement and number of chromosomes, providing information about potential genetic abnormalities. 11. [What are similarities and difference between human somatic cells and gametes?] Both human somatic cells and gametes are cells within the human body, but the key difference is that somatic cells are any regular body cell, making up the majority of the body\'s tissues, while gametes are sex cells (sperm and egg) specifically involved in reproduction 12. [Discuss the composition, shape and polarity of a DNA double helix?] A DNA double helix is composed of two polynucleotide strands twisted around each other, forming a helical shape, where each strand consists of a sugar-phosphate backbone with attached nitrogenous bases (adenine, thymine, cytosine, and guanine) that pair with complementary bases on the opposite strand, creating \"rungs\" within the helix; the key feature of polarity is that the two strands run in opposite directions, with one strand having a 5\' end and the other a 3\' end, referred to as antiparallel arrangement. 13. Draw and label a eukaryotic chromatid and list the function of each part? (Think of what role it plays in the cell cycles. 14. A true breeding white mouse was bred with a true breeding black mouse. Somehow all of their offspring were brown. When these brown mice were self-breeding, the resulting offspring posed three different pigment options black white or brown. How many genes are involved in this inheritance? What were the genotypes/phenotypes of the parent, F1 and F2 generations? What inheritance pattern does this represent?