Genetics- From Genes to Genomes Exam Questions with Verified Answers Latest Update 2024 (Graded A+)

Genetics- From Genes to Genomes Exam Questions with Verified Answers Latest Update 2024 (Graded A+) Continuous Traits - Answers Inherited trait that exhibits many intermediate form; determined by segregating alleles of many different genes whose interaction with each other and the environment produces the phenotype. Also called a quantitative trait. Complete Dominance - Answers One of the Parents trait is shown Epistasis - Answers Gene interaction in which the expression of 1 gene 'masks' the phenotypic display of a 2nd gene 50 units - Answers in order to have independent assortment the 2 genes need to be at least 50 units apart Product Rule - Answers If the events are independent,probability that both will occur is the product of each single Penetrance - Answers Indicates how many members of a population with a particular genotype show the expected phenotype Expressivity - Answers The degree or intensity with which a particular genotype is expressed in a phenotype Histones - Answers Small-binding proteins with a preponderance of the basic, positively charged amino acids lysine and arginine. Histones are the fundamental protein components of nucleosomes H2A, H2B, H3, H4 - Answers Core histones found in the nucleosome Nucleosome - Answers The basic repeating structural (and functional) unit of chromatin. Contains nine histone proteins and about 166 base pairs of DNA H1 - Answers bind to the nucleosome at the entry and exit sites of DNA (locking the DNA into place) Hemizygous - Answers males with one copy of an X-linked gene Holandric - Answers on Y chromosome(Y-linked traits are passed from father to sone. No interchromosomal genotype. Monavalent - Answers unpaired chromosome during meiosis Euchromatin - Answers Region of Lightly pack chromatin. Chromatin - Answers The generic term for any complex of DNA and protein found in a cell's nucleus Heterochromatin - Answers Highly condensed chromosomal regions within which genes are usually transcriptionally inactive Xist gene - Answers "X inactivation specific transcript"; produces a single-stranded RNA that coats the inactive X chromosome and initiates condensation.X inactivation is an early developmental process in mammalian females that transcriptionally silences one of the pair of X chromosomes, thus providing dosage equivalence between males and females. Done by splicing and polyadenylation. Nucleotides - Answers Organic molecules that serve as the monomers, or subunits, of nucleic acids like DNA and RNA. Composed of a nitrogenous base, a five-carbon sugar (ribose or deoxyribose), and at least one phosphate group. Nucleoside - Answers Simple base bound to a ribose or deoxyribose sugar via a beta-glycosidic linkage. (Guanine, Cytosine, Adenine, Thymine, Uracil) telomerase - Answers A ribonucleoprotein involved in replication. A reverse transcriptase that carries its own RNA molecule which is used as a template when it elongates telomeres, which are shortened after each replication cycle. Adds DNA sequence repeats to the 3' region to create telomeres to prevent the loss of DNA Telomere - Answers A region of repetitive nucleotide sequences at each end of a chromatid , which protects the end of the chromosome from deterioration or from fusion with neighboring chromosomes Chromatid - Answers One of 2 copies of a chromosome that exist immediately after DNA replication Topoisomerase - Answers Enzyme that regulates the overwinding or underwinding of DNA during replication. It moves ahead of the replication fork, breaking covalent bonds that connect deoxyribosenucleotides Helicase - Answers Enzyme that unwinds double stranded DNA to single Strand DNA for replication. Creates a fork, breaks hydrogen bonds Auxotroph - Answers A mutant microorganism that can grow on minimal medium only if it has been supplemented with one or more growth factors not required by wild type strains Prototroph - Answers Microorganism(usually wild type) that can grow on minimal medium in the absence of one or more growth factors Forward Mutations - Answers Changes wild type to a new type Transition - Answers Replacement of a purine with a purine or vice versa. Purine - Answers Adenine and Guanine (double ring) Pyramidine - Answers Uracil, Thymine, Cytosine. (single ring) Transversion - Answers replacement of pyramidine with purine or vice versa Reversion - Answers mutation that changes the mutant allele back to the wild type Inversion - Answers Segments of chromosomes that become reversed DNA polymerase - Answers move in 5' to 3' direction, needs a primer, has proof reading, continuous until done, faster, and has helices, synthesizes DNA RNA polymerase - Answers move in 5' to 3' direction, doesn't need a primer, doesn't have proof reading, has exonuclease activity, uracil base, synthesizes RNA MutS, MutH and MutL - Answers 3 proteins are essential in detecting the mismatch and directing repair machinery for methylation repair Methylation repair mechanism - Answers DNA repair mechanism that corrects mistakes in replication, discriminating between newly synthesized and parental DNA by tagging the parental strand with methyl groups. Exonuclease acitivity next then rejoined by ligase. Aminoacyl synthetase - Answers enzymes that catalyze the attachment of tRNAs to their corresponding amino acids, forming charged tRNAs - for translation Splice Donor Sequence - Answers Site within primary transcript that is cleaved 1st during splicing Eukaryotic RNA polymerase I - Answers transcription of ribosomal RNA genes Hypomorphic mutations - Answers altered gene product possesses a reduced level of activity/ wild type gene product is expressed and at reduced level Amorphic/null mutations - Answers altered gene product that lack molecular function of wild type gene- (gene function doesn't work anymore) Neomorphic mutations - Answers altered gene product possesses new or different function that is usually dominant or semi-dominant Hypermorphic Mutations - Answers altered gene product that is expressed at an increased level Conditional Mutations - Answers Individual needs to be placed in a specific environment for mutation to be expressed Hershey Chase Experiment - Answers Proved that DNA was the genetic material by using bacteriophages, radioactive sulfur(protein), and radioactive phosphorous(DNA). The phosphorous was the only thing found in the cell, proving that DNA is the genetic material. DNA association - Answers Phosphorous Protein association - Answers sulfur Heteroduplex - Answers region of double-stranded(duplex) molecule of nucleic acid originated through the genetic recombination of single complementary strands derived from different sources(started from the mismatch), such as from different homologous chromosomes or even from different organisms. Genetic recombination. Holiday Model - Answers When there is a cross, 2 ways that can be separated, one giving nonrecombinant and the other recombinant( by isomerization by twisting it 180 degrees) both use endonuclease and ligase for putting it back together. Ames Test - Answers Tests whether a mutagen is carcinogenic by mixing liver enzymes with the mutagen then plating on media with minimal histidine media, a lot of colonies means it is mutagenic Shine-Dalgarno Sequence - Answers ribosomal binding site in prokaryotic mRNA, located around 8 bases upstream of the start codon AUG. It helps recruit the ribosome to the mRNA to initiate protein synthesis by aligning it with the start codon. TATAA box - Answers Sequence found in the promoter region of genes in arches and eukaryotes. Considered to be the core promoter sequence. It is the binding site of either general transcription factors or histones(the binding of transcription factor blocks the binding of a histone and vice versa) and is involved in the process of transcription by RNA polymerase Primase - Answers makes RNA primer for Polymerase III Polymerase I - Answers Replaces RNA to DNA from Okazaki fragment DNA ligase - Answers Mends the Okazaki fragments together with covalent bonds Missense mutations - Answers Point mutation where a single nucleotide change that codes for a different amino acid Nonsense Mutation - Answers Point mutation that results in a premature stop codon Frameshift - Answers Insertion that shifts the nucleotide sequence, changing the amino acid Complementation Testing - Answers Can be used to test whether the mutations in two strains are in different genes. Complementation will not occur if the mutations are in the same gene. ("+"s or "-"s) Complementation - Answers Occurs when two strains of an organism with different homozygous recessive mutations that produce the same phenotype Sigma Factor - Answers A protein needed only for initiation of RNA synthesis. It is a bacterial transcription initiation factor that enables specific binding of RNA polymerase to gene promoters