Microbiology Chapter 9 Smartbook

Which of the following is a type of mutation that affects only a single base pair in DNA? Silent Back Point Missense

Point

Which two statements regarding eukaryotic transcription and RNA processing are correct? Transcription occurs before splicing. The exon-intron junction is recognized by a spliceosome. Splicing to remove introns occurs in the cytoplasm. A series of thymines is added to the mRNA.

Transcription occurs before splicing. The exon-intron junction is recognized by a spliceosome.

Horizontal gene transfer

Transfer of DNA from a source other than the parent organisms

Vertical gene transfer

Transfer of DNA from parent organisms during reproduction

Most bacterial plasmids carry an origin of replication and at most ______ genes. a few hundred a few dozen a few thousand

a few dozen

The science of heredity is ______.

genetics

Phase variation is when bacteria turn on or off a set off genes, which leads to obvious changes in their ________.

phenotype

Unlike DNA, RNA contains the nitrogenous base _____.

uracil

In the central dogma, DNA encodes _____ which encodes protein.

RNA

When organisms acquire genes which did not come directly from parent organisms it is referred to as _______ gene transfer.

horizontal

The transfer of genes from donor to recipient in microorganisms, where the recipient strain shows a change in genetic makeup at the end, is referred to as ___________ .

recombination

Mutations that occur because of errors in DNA replication are termed ______.

spontaneous

True or false: Mutations are always harmful to cells.

False

True or false: Operons are found in fungi and helminths.

False

True or false: The chromosome is a small circular segment of DNA found in the cytoplasm of prokaryotes that is capable of independent replication and usually contains nonessential genes.

False

True or false: Viral genomes are always composed of either single or double stranded DNA.

False

Which term refers to the transfer of genes from donor to recipient microorganisms? Mutation Recombination Heredity Reproduction

Recombination

A mutation that affects only a single base pair in DNA is termed a _____ mutation.

point

During translation elongation, peptide bonds form between: RNA nucleotides Amino acids DNA and RNA nucleotides DNA nucleotides

Amino acids

The genes of which microorganism(s) are arranged as operons? Fungi Bacteria Protozoa

Bacteria

The antibiotic rifamycin can be used to treat tuberculosis because Blank______. a) the drug binds effectively to bacterial ribosomes and causes rapid death of the pathogen b) the drug is more active against bacterial RNA polymerase than the human enzyme c) the drug binds very effectively to bacterial DNA and blocks transcription, leading to death of the pathogen d) the drug is more active against human RNA polymerase than the bacterial enzyme

b) the drug is more active against bacterial RNA polymerase than the human enzyme

The genes of the lac operon in E. coli encode enzymes that ______. catabolize lactic acid catabolize glucose anabolize lactose catabolize lactose

catabolize lactose

Horizontal gene exchange via pili in bacteria is called _______.

conjugation

Which term represents all of the genetic information within a cell?

genome

A permanent inheritable alteration in the DNA sequence of a cell is a(n) _______ .

mutation

A small number of _______ are considered beneficial in that they provide the cell with a useful change in structure or physiology. Antibiotic resistance in bacteria is an example.

mutations

Building blocks of DNA, called ___________ , contain the same sugar and phosphate, but different nitrogenous bases.

nucleotide

All DNA nucleotides contain Blank______. the same nitrogenous base and phosphate, but different sugars the same sugar, but different phosphates and nitrogenous bases the same nitrogenous base, but different phosphates and sugars the same sugar and phosphate, but different nitrogenous bases

the same sugar and phosphate, but different nitrogenous bases

Which of the following are areas of the genome where multiple genes exist that are coordinated to create a new trait, making the bacterium more pathogenic? Insertion elements Polymerase Transposons Pathogenicity islands

Pathogenicity islands

True or false: A mutation is an alteration in the DNA sequence or content of a cell that is passed on when the cell divides.

True

True or false: DNA replication must occur prior to cell division to ensure that each new cell has a complete set of DNA chromosome(s).

True

True or false: The structure of DNA is essential for providing variety since the order of nucleotides is responsible for the unique qualities of each organism.

True

The arginine operon is "on" when the cell is Blank______. dormant actively growing slowing down

actively growing

When a cell is actively growing, the arg operon is Blank______, and arginine is Blank______. off; consumed in biosynthesis on; actively synthesized off; actively synthesized on; consumed in biosynthesis

on; actively synthesized

DNA repair enzymes have as their substrate Blank______. mutagens messenger RNA missense mutations damaged DNA

damaged DNA

_______ is the study of the inheritance of living things.

genetics

The lac operon in E. coli regulates the metabolism of ________.

lactose

What is the central dogma hypothesis of genetics? 1. DNA encodes RNA which encodes protein 2. Protein encodes RNA which encodes DNA 3. RNA encodes DNA which encodes protein

1

Which of the following signifies translation termination? A nonsense codon is reached and the peptide is released from the ribosome tRNA leaves the E site on the ribosome A terminator sequence is reached and mRNA is released from the DNA template

A nonsense codon is reached and the peptide is released from the ribosome

Which two of the following statements regarding eukaryotic transcription and RNA processing are correct? Transcription occurs after splicing. A series of adenosines is added to the mRNA. Splicing to remove introns occurs in the nucleus. The exon-intron junction is recognized by a ribosome.

A series of adenosines is added to the mRNA. Splicing to remove introns occurs in the nucleus.

Detection of mutagenic and potentially carcinogenic agents based upon the genetic alteration of nutritionally defective bacteria is called the _____ test.

Ames

Which test is a method of detecting mutagenic and potentially carcinogenic agents based upon the genetic alteration of nutritionally defective bacteria?

Ames

During translation elongation, peptide bonds form between: DNA and RNA nucleotides DNA nucleotides RNA nucleotides Amino acids

Amino Acids

A sequence of three consecutive nucleotide bases in DNA that encodes an amino acid is a(n) ______ .

Blank 1: triplet or triplets

Which of the following are methods of gene transfer in bacteria? Conjugation Transduction Transformation Translation Transcription

Conjugation Transduction Transformation

True or false: Bacterial conjugation is a sexual process.

False

Which two of the following statements regarding plasmids are true? Plasmids are essential for bacterial survival. Many bacteria carry plasmids in addition to their chromosome. A typical bacterial plasmid will have a few hundred genes. Plasmids may contain genes that specify resistance to antibiotics.

Many bacteria carry plasmids in addition to their chromosome. Plasmids may contain genes that specify resistance to antibiotics.

Areas of the genome containing multiple genes which contribute to a new trait for the organism that increases its ability to cause disease are termed _______ .

Pathogenicity islands

How does RNA differ from DNA in bacteria and eukaryotes? RNA is single-stranded In RNA, thymine is replaced with adenine Ribose in RNA contains one less carbon than deoxyribose in DNA. In RNA, uracil replaces thymine

RNA is single-stranded In RNA, uracil replaces thymine

The antibiotic rifamycin, used to treat tuberculosis, binds and inhibits the activity of Blank______. biosynthetic operons RNA polymerase ribosomes the lac repressor

RNA polymerase

The enzyme that transcribes DNA into RNA is ________________.

RNA polymerase

Which enzyme transcribes DNA into RNA?

RNA polymerase

Which of the following is the genetic pattern of viral genomes? Single stranded DNA only Single or double stranded DNA or RNA Single or double stranded DNA only Double stranded DNA only

Single or double stranded DNA or RNA

Horizontal gene exchange via pili in bacteria is called ________.

conjugation

Ensuring that the DNA code will be maintained during cell growth and cell _______ is one of the two essential effects of the structure of DNA.

division

DNA damage can be resolved by ______.

enzymes

A spontaneous mutation arises in DNA from Blank______. treatment with ultraviolet light gene expression transposable elements moving in the chromosome errors in DNA replication

errors in DNA replication

The complete set of chromosomes and genes in an organism is referred to as the ________.

genome

The process of bacteria turning on or off a group of genes that changes its phenotype in a heritable manner is called ____________ .

phase variation

A small circular segment of DNA found in the cytoplasm of bacteria that is capable of independent replication and usually contains nonessential genes is called a(n) ______ .

plasmid

During semiconservative ________ the DNA is duplicated prior to binary fission.

replication