Foundations in Microbiology Chapter 9 Exam Questions and Verified Answers (Graded A+)

Foundations in Microbiology Chapter 9 Exam Questions and Verified Answers (Graded A+) Genetics - Answers the study of heredity DNA - Answers Heredity material, protein building material Chromosome - Answers A threadlike linear strand of DNA and associated proteins in the nucleus of eukaryotic cells that carries the genes and functions in the transmission of hereditary information. Gene - Answers A hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism. Plasmid - Answers A circular, double-stranded unit of DNA that replicates within a cell independently of the chromosomal DNA. Genotype - Answers The genetic makeup, as distinguished from the physical appearance, of an organism or a group of organisms. Phenotype - Answers The observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences. Genome - Answers An organism's genetic material. DNA - Answers deoxyribonucleic acid; a nucleic acid that is the main constituent of the chromosomes of all organisms DNA replication - Answers is semiconservative and requires the participation of several enzymes DNA is used to produve RNA through______ and RNA is then used to produce protein through_______ - Answers transcription; translation RNA - Answers is single stranded, cantains a uracil base, and the sugar ribose. _____ in the mRNA pair with _____ in the tRNA to specify what amino acids to assemble on the ribosome during translation - Answers Codons; anticodons tRNA - Answers short-chain RNA molecules present in the cell (in at least 20 varieties, each variety capable of combining with a specific amino acid) that attach the correct amino acid to the protein chain that is being synthesized at the ribosome of the cell. mRNA - Answers type of RNA that carries instructions from DNA in the nucleus to the ribosome rRNA - Answers type of RNA that makes up part of the ribosome Codons - Answers A three-nucleotide sequence of DNA or mRNA that specifies a particular amino acid or termination signal; the basic unit of the genetic code. Anticodon - Answers A sequence of three bases of a tRNA molecule that pairs with the complementary three-nucleotide codon of an mRNA molecule during protein synthesis. Transcription occurs when ___________ copies the template strand of a segment of DNA - Answers RNA polymerase RNA is always made in the _______ direction - Answers 5' - 3' Translation occurs when the ____ is used to direct the synthesis of proteins on the _____ - Answers nRNA; Ribosome Eukaryotic genes are compsed of _____and _____ - Answers exons; introns A nucleotide consists of a _______, a________, and a_______. - Answers phosphate, deoxyribose sugar, and nitrogen base operon - Answers a segment of DNA containing adjacent genes including structural genes and an operator gene and a regulatory gene mutations - Answers Random errors in gene replication that lead to a change in the sequence of nucleotides; the source of all genetic diversity spontaneous mutation - Answers a chromosomal and gene mutation that occurs naturally induced mutation - Answers a mutation caused by a chemical agent or radiation point mutation - Answers mutation that affects a single nucleotide, usually by substituting one nucleotide for another missense mutation - Answers The most common type of mutation, a base-pair substitution in which the new codon makes sense in that it still codes for an amino acid. nonsense mutation - Answers A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein. silent mutation - Answers A mutation that changes a single nucleotide, but does not change the amino acid created. back mutation - Answers when a mutated gene reverses to its original base composition Ames test - Answers test for mutagenicity used as a screen for carcinogen potential using auxotrophs for their point mutations transduction - Answers the process of transfering genetic material from one cell to another by a plasmid or bacteriophage transposens - Answers Movable genetic elements.... change DNA from molecule to molecule. May carry antibiotic resistance genes.