Biology - Chapter 7 HW

Based upon what you know about transcription, which side of the image, A or B, is closer to the promoter region of the gene being transcribed?

A

In a frameshift mutation, all of the amino acids before the shift are changed.

FALSE

Consider the types of mutations and the circumstances in which mutations arise to select those TRUE statements below. (Select all that apply.)

Insertions, but not deletions, can change the codon reading frame. Mutations can be useful to the organism.

What is wrong with the following piece of mRNA? TACCAGGATCACTTTGCCA

It contains T and not U.

Use the DNA template strand below to synthesize a polypeptide. Write your answer in the box below. Use the one-letter amino acid abbreviations in your answer (see figure 7.7). For example, if you determine the amino acid sequence is serine-proline-lysine, type SPK as your answer. Template strand: AATACGGCC

LCR

Select the components present in all viruses. (Select all that apply.)

Protein coat Genetic material

Gene expression step - simple Is transcription or translation shown in the image below?

TRANSCRIPTION

The addition of a single nucleotide to the DNA sequence causes a frameshift mutation.

TRUE

What is similar between the lysogenic cycle of a bacterial virus and the HIV infection cycle?

The viral genome is integrated into the host chromosome.

Use the DNA template strand below to create a complementary RNA strand. Type the complementary RNA strand in the box. Template strand: AATACGGCC

UUAUGCCGG

According to the image below, a mutation in a gene is analogous to

a typo in a recipe.

A single nucleotide deletion during DNA replication

causes the amino acids encoded by nucleotides after the deletion to be incorrect.

What step of gene expression is shown in the figure?

elongation stage of transcription

Infection with HIV viruses causes the death of immune system cells called ______, and over many years, HIV can lead to a disease called ______, in which the immune system is deficient.

helper T cells; AIDS

The nucleotide sequence in mRNA is determined by

nucleotide sequence of DNA

Review the genetic code, and then complete the sentence below the table. Complete this sentence: If the nucleotides ATT were inserted into the template strand of a gene, then

the resulting protein will be shorter and nonfunctional.

AZT is a drug that is commonly used to fight HIV infection. The active component of AZT is a nitrogenous base that mimics thymine. Normal nucleotides CANNOT covalently bond to the thymine mimic. HIV's reverse transcriptase enzyme will use the thymine mimic instead of using thymine, whereas our DNA polymerase will not make this mistake. What is the most likely explanation for how AZT prevents HIV replication?

The DNA strand produced by reverse transcriptase will stop being synthesized the first time the thymine mimic is inserted.