BIO 320 Exam 2 Study Guide Solutions

BIO 320 Exam 2 Study Guide Solutions Gene - ANSWER-a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring Genome - ANSWER-the complete set of genes or genetic material present in a cell or organism Introns - ANSWER-non-coding sections of the RNA that are spliced out before the RNA is translated into a protein Exons - ANSWER-coding sections of the RNA that will not be spliced out and will be present in mRNA Mature eukaryotic mRNAs have well-defined 3' ends terminating in _____. - ANSWER-poly-A tails Eukaryotic mRNA have a _____ consisting of a 7-methyl guanosine residue joined to the transcript's initial nucleotide. - ANSWER-5' cap Solitary Gene - ANSWER-there is only one copy of the gene, descriptive of most genes The protein-coding sequences without including introns make up what percentage of the human genome? - ANSWER-1.5 ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 2/29 What are the two genes that are tandemly repeated in the human genome? - ANSWER-tRNA and histones Simple Sequence DNA - ANSWER-constitutes about 6% of the human genome, also called satellite DNA, concentrated near the centromere, backward slippage is used, number of repeats are vastly different, simple sequence is mobile; doesn't code for anything Paternity determination and criminal identification are based on the variability of the number of the __________ of each individual. - ANSWER-simple-sequence DNA Simple Sequence DNAs are known to be located in which areas of the chromosome - ANSWER-found in centromere and some in telomere; interacts with the kinetochore Simple Sequence DNA are made by which mechanism? - ANSWER-backward slippage The simple sequence DNA found in telomeres is synthesized by... - ANSWER-telomerase The tandem repeat sequence to be added on to the 3' end of DNA by telomerase is... - ANSWER- TTAGGG The RNA template sequence required for synthesizing he tandem repeat sequence is... - ANSWER- AAUCCC ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 3/29 What would be the consequence of down-regulation of telomerase activity during in vitro cell culture? - ANSWER-the chromosome would get shosrter and shorter each time it divided, essential genes would be lost Telomerase is a type of... - ANSWER-enzyme: protein-RNA complex DNA Transposon - ANSWER-~3% of genome, a cut and paste mechanism, has inverted repeats Retrotransposon - ANSWER-~42% of genome, a copy and paste mechanism, has longer terminal repeat that is not inverted Transposons - ANSWER-constitutes about 25-50% of the human genome, mobile, selfish DNA What mobile sequence is able to move or transpose to a new site of DNA by cutting and pasting it into a target sequence of DNA? - ANSWER-DNA transposons A primary enzyme that facilitates the transposition of the IS10 element. - ANSWER-transposase How do selfish DNA transposons increase in frequency in the genome? - ANSWER-transposase makes blunt-ended cuts in the donor DNA and staggered cuts in the target DNA. Then it ligates the insertion enzyme to 5' single stranded ends of target DNA. Then the cellular DNA polymerase extends the 3' cut ends and the ligase joins the extended 3' ends to the insertion enzyme 5' ends ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 4/29 Describe the fundamental structural difference between LTR retrotransposon and IS2 element. - ANSWER-the LTR retrotransposon has direct repeats on each side of the protein coding region while the IS2 eleement has an inverted repeat on one side Which molecules are required for the transposition of LTR retrotransposon. - ANSWER-RNA polymerase, RNA processing enzymes, Poly(A) polymerase LINE is a type of _____ that encodes _____ which is used for the hopping of the LINE sequence into the target site. - ANSWER-retrotransposon; reverse transcriptase Alu sequence is and example of a _____ - ANSWER-short interspersed element Short INterspersed Elements - ANSWER-retrotransposons that do not encode protein; they repair damaged DNA Heterochromatin - ANSWER-small, darkly staining, irregular particles scattered throughout the nucleus and accumulated next to the nuclear envelope, abundant in cells that are less/not active Euchromatin - ANSWER-dispersed but not stainable, prevalent in c