AP BIOLOGY CHAPTER 17 - PART 3

According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway?

2

When the function of the newly made polypeptide is to be secreted from the cell where it has been made, what must occur?

Its signal sequence must target it to the ER, from which it goes to the Golgi

In comparing DNA replication with RNA transcription in the same cell, which of the following is true only of replication?

The entire template molecule is represented in the product

In order for a eukaryotic gene to be engineered into a bacterial colony to be expressed, what must be included in addition to the coding exons of the gene?

a bacterial promoter sequence

Which small-scale mutation would be most likely to have a catastrophic effect on the functioning of a protein?

a base deletion near the start of a gene

The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. This results in

a polypeptide missing an amino acid

If a protein is coded for by a single gene and this protein has six clearly defined domains, which number of exons below is the gene likely to have?

8

Gene expression in the domain Archaea in part resembles that of bacteria and in part that of the domain Eukarya. In which way is it most like the domain Eukarya?

Domain Archaea have numerous transcription factors

What is the effect of a nonsense mutation in a gene?

It introduces a premature stop codon into the mRNA

Which of the following is true of transcription in domain Archaea?

It is roughly simultaneous with translation

Why might a point mutation in DNA make a difference in the level of protein's activity?

It might substitute an amino acid in the active site

Suppose that a mutation alters the formation of a tRNA such that it still attaches to the same amino acid (phe) but its anticodon loop has the sequence AAU that binds to the mRNA codon UUA (that usually specifies leucine leu).

One mutated tRNA molecule will be relatively inconsequential because it will compete with many "normal" ones.

When the genome of a particular species is said to include 20,000 protein-coding regions, what does this imply?

There are also genes for RNAs other than mRNA

Which of the following statements is true about protein synthesis in prokaryotes?

Translation can begin while transcription is still in progress

n the 1920s Muller discovered that X-rays caused mutation in Drosophila. In a related series of experiments in the 1940s, Charlotte Auerbach discovered that chemicals-she used nitrogen mustards-have a similar effect. A new chemical food additive is developed by a cereal manufacturer. Why do we test for its ability to induce mutation?

We want to prevent any increase in mutation frequency

Of the following, which is the most current description of a gene?

a DNA sequence that is expressed to form a functional product: either RNA or polypeptide

Which of the following DNA mutations is the most likely to be damaging to the protein it specifies?

a base-pair deletion

Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?

a deletion of two nucleotides

Which of the following mutations is most likely to cause a phenotypic change?

a single nucleotide deletion in an exon coding for an active site

A frameshift mutation could result from

either an insertion or a deletion of a base