Weekly Homework - DNA, Chromosomes, Structure - PDF

Weekly Homework – DNA, Chromosomes, Structure 30 pts Due: January 26 11:59pm IMPORTANT: You MUST use this fillable form provided to submit your homework. Homework that is submiDed without using the fillable form will not be graded and will receive a zero. Answers that extend...

Weekly Homework – DNA, Chromosomes, Structure 30 pts Due: January 26 11:59pm IMPORTANT: You MUST use this fillable form provided to submit your homework. Homework that is submiDed without using the fillable form will not be graded and will receive a zero. Answers that extend beyond the box are not visible on Gradescope. If you use an electronic pencil to answer quesLons, wriLng must be legible and be contained within the fillable box. SecLon 1: MulLple Choice, MulLple Answer. Read each quesLon carefully. Mark each opLon that answers the quesLon asked. DO NOT mark answers that do not apply. Some quesLons may have only one correct answer. Some quesLons may have more than one correct answer. Each blank is worth 0.5pts. 1. Which of the following is the most complete, correct definiLon of a gene? ____DNA that codes for a protein ✔ ____Specific segment of DNA in a discrete region of a chromosome that codes for a func8onal product ____Specific segment of DNA in a discrete region of a chromosome ____A sequence of amino acids that forms a three-dimensional structure and produces a phenotype 2. Which of the following is explained by Mendel’s law of independent assortment? ____If the parent genotype is Aa, the probability of ge@ng allele A or allele a in a gamete is equally likely. ____A locus can be heterozygous. ____One allele can be dominant or mask another allele for the same gene. ✔ ____The alleles for one gene (Aa) and the alleles for another gene (Bb) will be found in equal propor8ons in the offspring. 3. Which of the following is explained by Mendel’s law of segregaLon? ✔ the parent genotype is Aa, the probability of ge@ng allele A or allele a in a gamete is equally likely. ____If ____A locus can be heterozygous. ____One allele can be dominant or mask another allele for the same gene. ____The alleles for one gene (Aa) and the alleles for another gene (Bb) will be found in equal propor8ons in the offspring. 4. Tm ____refers to the temperature that causes phosphodiester bonds between nucleo8des to break ✔ ____refers to the temperature that causes hydrogen bonds between bases to break ____is higher when the GC content of the sequence is lower ✔ higher when the GC content of the sequence is higher ____is 5. Topoisomerases ✔ ____are a highly conserved family of proteins that are found in both bacteria and eukaryotes. ✔ DNA so that addi8onal twists can be added or taken away. ____cut ✔ ____assist with DNA compac8on and DNA replica8on. ✔ ____nick one or both DNA strands, depending on the specific type. Weekly Homework – DNA, Chromosomes, Structure 30 pts Due: January 26 11:59pm 6. Which of the following is a DNA sequence that is complementary to 5’-TAGAC-3’? ____5’-TAGAC-3’ ✔ ____5’-GTCTA-3’ ____5’-ATCTG-3’ ____5’-UAGAC-3’ ____5’-GUCUA-3’ 7. Which of the following are characterisLcs of DNA organizaLon in Eukaryotes? ____dsDNA is organized into circular chromosomes and is located in the nucleus. ✔ ____Chromosomes are highly organized and found in specific regions or territories of the nucleus. ____Supercoiling is the primary mechanism that allows chroma8n to be condensed enough to fit into the nucleus. ✔ ____Nucleosomes play a cri8cal role in assis8ng the compac8on of chroma8n. ✔ ____DNA organiza8on is dynamic, changing from 8ghtly packed structures to more open areas depending on the stage of the cell cycle. 8. Which of the following are true about the packaging of DNA in eukaryoLc chromosomes? ✔ ____Condensins form chroma8n loops that are approximately 300nm wide ____Condensins decondense chromosomes aTer mitosis. ____Chromosomes reach maximum compac8on during prophase. ✔ ____Nucleosomes coil and stack into 30nm chroma8n fibers. SecLon 2: Short Answer, Fill in the Blank, Diagrams, Matching. Read each quesLon carefully. Some quesLons have mulLple parts. 9. In a diploid organism where n = 4 chromosomes, how many chromosomes are expected to be present in somaLc cells? How many chromosomes are expected in mature gamete cells (2pts)? Soma8c cells: 8 chromosomes, one set of 4 chromosomes from each parent Mature gamete cells: 4 chromosomes (following reduction division in meiosis) Weekly Homework – DNA, Chromosomes, Structure 30 pts Due: January 26 11:59pm 10. Recall base structure (5 pts): a. Write the name of each base shown. Cytosine Adenine Thymine Uracil Guanine b. Which of the structures (A, B, C, D, E) above are pyrimidines? A,C,D - single ring structures c. Which of the structures (A, B, C, D, E) above are purines? B, E - double ring structures 11. Four classes of macromolecules exist in cells and were once considered possible carriers of geneLc informaLon: Carbohydrates, Lipids, Proteins, and Nucleic Acids. For each molecule type, place a check mark next to the observaLons that apply to each (3pts): Carbohydrates and Lipids: Proteins: Nucleic Acids: ____Informa8on-rich ✔ ____Informa8on-rich ✔ ____Informa8on-rich ____Can self-replicate ____Can self-replicate ✔ ____Can self-replicate ✔ ____Distributed throughout cell ✔ ____Distributed throughout cell ____Distributed throughout cell ____Concentrated in Nucleus ____Concentrated in Nucleus ✔ ____Concentrated in Nucleus 12. Fill out the following table according to the roles of each histone modificaLon type (3pts): Histone modificaLon Enzyme/Protein Name Effect on histone charge Effect on chromaLn packing AcetylaLon HAT, histone Neutralizes positive loosens packing acetyltransferase histone charge MethylaLon HMTs, histone No change context-dependent, often methyltransferase increases/tightens packing