DNA: Errors and Mutations

Conjugation is a very effective process for spreading antibiotic resistance. What best explains this observation?

Two different strains of bacteria can transfer DNA during conjugation.

How do mutations affect an organism?

-they may cause the development of -they may cause the development of a more beneficial allele -they, in some cases, may have no noticeable affect

From which cell does the sex pilus originate during bacterial conjugation?

The donor cell

_____ is the direct transfer of DNA from one bacterium to another.

Conjunction

A typical animal RNA virus has an outer membrane envelope that helps the virus enter and leave the host cell. What makes up this outer membrane envelope?

The virus coats itself in the host cell's plasma membrane.

_____ occurs when a phage transfers bacterial DNA from one bacterium to another.

Transduction

True or False. During bacterial conjugation, the recipient cell receives a single-stranded loop of DNA.

True

True/False regarding protein synthesis: Messenger RNA is made on a DNA template, and then amino-acid-bearing tRNAs line up on it through codon-anticodon pairing.

True

Any change in the nucleotide sequence of DNA is called

a mutation.

Emerging viruses can originate from _____.

a virus spreading from one host species to another

One cell has given a copy of a plasmid to another cell and kept one copy for itself, best describes the end result of _____?

bacterial conjugation

Consider the following sentence: "The dog did not eat." The doe did not eat: is most like a _____?

base substitution mutation

Genetic mutations _____.

can occur naturally

Ultraviolet (UV) radiation is damaging because it _____.

causes mutations in DNA

Where is cat? ("Where is the cat" original) is most like a chromosomal _____?

deletion

The 2009 H1N1 flu virus

evolved through the genetic reshuffling of viruses that infect humans, birds, and pigs.

A female that is planning to become pregnant is concerned about her exposure to environmental mutagens which may have caused DNA mutations. In order for these mutations to become heritable, they must affect the:

her egg cells

If a chromosome fragment breaks off and then reattaches to the original chromosome, but in the reverse direction, the resulting chromosomal abnormality is called a(n)

inversion

The lytic cycle of bacteriophage infection ends with the _____.

rupture of the bacterium

The type of mutation represented below is a(n) _____. The big red fly had one eye (wild type) The fbi gre dfl yha don eey (mutant)

shift in reading frame

DNA replication occurs at an unbelievably fast rate. Once replication is complete, we can expect to find a _____ number of mistakes.

small

A geneticist found that a particular mutation had no effect on the polypeptide encoded by a gene. This mutation probably involved _____.

substitution of one nucleotide

Cancer is not usually inherited because

the chromosomal changes in cancer are usually confined to somatic cells.

As a result of the lytic cycle, _____.

the host cell's DNA is destroyed

Viral DNA makes mRNA by the process of _____.

transcription

A friend accidentally sends an email to you that contains a computer virus from his computer. Without knowing it, you infect your computer with the virus when you open the email. This process of spreading the computer virus using emails is most like what processes?

transduction

A microbiologist found that a colony of bacterial clones infected by a phage had developed the ability to make a particular amino acid that the bacteria could not make before the infection. This new ability was probably a result of _____.

transduction

During the process of translation, _____ matches an mRNA codon with the proper amino acid.

transfer RNA

In the 1920s, Frederick Griffith conducted an experiment in which he mixed the dead cells of a bacterial strain that can cause pneumonia with live cells of a bacterial strain that cannot. When he cultured the live cells, some of the daughter colonies proved able to cause pneumonia. What processes of bacterial DNA transfer does this experiment demonstrate?

transformation

True/False: Transcription occurs in the cytoplasm of eukaryotic cells.

False

True/False: Very few new human diseases have originated in other animals because the genetic differences are too great.

False

You suspect that a serious developmental disorder is due to a chromosome abnormality and prepare a karyotype from an affected individual. In analyzing the karyotype, how could you distinguish trisomy from a chromosome structural defect such as a duplication?

In trisomy there would be one extra chromosome; in a duplication, one chromosome would have two copies of a portion of the chromosome.

Imagine a DNA replication error that results in the replacement of a "T" in one of the genes with a "G" instead. What effect would this have on the cell?

One of the proteins might contain an incorrect amino acid.

A virus infects a cell and randomly inserts many short segments of DNA containing a stop codon throughout the organism's chromosomes. This will probably cause _____.

manufactured proteins to be short and defective

A physical or chemical agent that changes the nucleotide sequence of DNA is called a(n)

mutagen