Chapter 11: DNA BiologyAssignment

Choose three (3) correct statements about the promoter region.

- It is where RNA polymerase binds on DNA. - It is located on the DNA strand. - It marks the beginning of a new gene.

In the lac operon, when lactose is present, which of the following are true?

- RNA polymerase binds to the promoter on the lac operon. - Lactose binds to the repressor and changes its shape.

Select the double-ringed purines.

- adenine - guanine

Select all of the following which take place during gene expression.

- binding of tRNAs to their specific amino acids - the joining of the small and large subunits of the ribosome - transcription of the DNA into an mRNA template - binding of codons to anticodons

Which of the following are possible with additional nucleotides in the genetic code?

- food with higher nutritional content - pathogen resistant organisms - far greater potential amino acids - new drugs and vaccines

Alternative mRNA processing involves which two of the following?

- removal of introns - splicing together of exons

Choose the two steps involved in gene expression from the choices below.

- translation - transcription

Events are in order by which they occur during gene expression.

1. the mRNA transcript is produced in the nucleus 2. the mRNA transcript binds to the ribosome 3. the tRNA anticodon binds its complementary codon bringing its specific its amino acids to the ribosome. 4. a polypeptide is synthesized as the mRNA is read and more amino acids are brought by the tRNAs 5. at termination, the ribosomal subunits and the mRNA dissociate

The traditional nucleotides, A, C, T and G, code for

20 amino acids.

What is a dark-staining portion of female, mammal DNA containing an inactive X chromosome called?

Barr body

transcription

DNA is used as a template to produce RNA.

replication

DNA is used as a template to produce duplicate molecules of DNA.

Which choice identifies the flow of information according to the central dogma of molecular biology?

DNA to RNA to protein

Which of the following is true about gene expression in different cells?

Each cell has the full complement of genes but only certain ones are expressed.

True or false: All somatic cells in the human body contain the same combinations of proteins.

False; All cells have the same chromosomes, but each cell type contains its own mix of proteins that makes it different from other cell types.

True or false: When chromatin is condensed, transcription is active.

False; Chromatin must be decondensed in order for transcriptional factors to have access to the template strand.

Where does protein synthesis occur?

In the cytoplasm

When lactose is present, what happens to the repressor?

It becomes inactive.

translation

RNA is used to produce protein.

During transcription, the enzyme complex known as __________ creates an RNA molecule by joining nucleotides complementary to a DNA template.

RNA polymerase

During transcription, what is the name of the enzyme complex responsible for opening up the DNA strand so base pairing can occur?

RNA polymerase

Which of the following is NOT a level of eukaryotic gene expression control?

Replicational control

DNA replication occurs during the ___________ phase of the cell cycle.

S

Use the genetic code to answer this question. The amino acid specified by the codon ACC is

Thr or threonine

When a repressor protein binds to the operator of a gene, what is the effect on transcription of that gene?

Transcription does not occur.

Which one of the following is the protein required for the initiation of transcription by RNA polymerase in eukaryotes?

Transcription factor

True or false: A newly translated eukaryotic polypeptide often must go through modification before becoming an active gene product.

True

True or false: The products of DNA transcription of a gene for a protein are known as mRNA transcripts.

True; : mRNA transcripts are produced during the transcription of DNA.

If a template strand of DNA has the base sequence order AATGCC, which of the following is the base sequence order for the resulting mRNA transcript?

UUACGG

Barr bodies are found in the ______ chromosome.

X

Identify the new nucleotides that have been created by scientists.

Y; X

The product of the transcription of a strand of DNA is

a complementary strand of RNA (transcription produces all 3 types of RNA; mRNA, rRNA, & tRNA)

Chromatin structure helps control gene expression by

allowing transcription when it is decondensed.

During the process of translation, a codon matches up with its complement, a(n)

anticodon

The three-base sequence in a tRNA molecule that pairs with a complementary codon on mRNA is known as a(n) _____.

anticodon

codon

binds to the ribosome and to the anticodon

amino acid

brought to the ribosome by tRNA

A three-nucleotide unit on a strand of mRNA that codes for a specific amino acid is called a

codon

Match the terms on the left with their best match on the right.

codon- mRNA anticodon- tRNA protein- amino acid

UUU and UUG are both examples of _____ that correspond to the amino acid phenylalanine in the genetic code.

codons

The mRNA transcript produced during transcription is _____ to the original strand of DNA.

complementary

Female mammals have a(n) ______ amount of protein product from genes located on the X chromosomes compared to the amount of gene product from genes on autosomes.

decreased

Changes in gene regulation at the cellular level which are inherited from one generation to the next is known as __________ inheritance.

epigenetic

X-inactivation, which can be physically observed in the coloring of calico cats, is an example of _________ inheritance, which does not result from changes in the sequence of nucleotides on the chromosome.

epigenetic

When condensed chromatin is unpacked and accessible for transcription, it is called _____.

euchromatin

Most of the time, DNA is only loosely coiled, a form called __________ , which allows genes to be active.

euchromatin or chromatin

Segments of mRNA that contain the protein-coding portion of a gene, which are joined together during splicing, are called _____.

exons

The coding portions of a gene that are joined during mRNA processing are called

exons

The portion of the chromatin that is inactive is called _______.

heterochromatin

Heterochromatin is a portion of the chromatin that is

inactive

During RNA process which structures are removed from the strand?

introns

Most genes in humans are interrupted by segments of DNA that do not code for a protein. These segments, which are removed from mRNA during mRNA processing, are called

introns

What are the segments of noncoding human DNA, which are removed from mRNA during mRNA processing, called?

introns

In alternative mRNA processing, eukaryotic gene expression is controlled when __________ are removed from the original transcript and the remaining __________ are spliced together before the final transcript exits the nucleus.

introns; exons

This diagram depicts the alteration of an insulin molecule, a polypeptide, from its form immediately after synthesis to its active structure. This alteration of insulin

is a means of controlling the expression of the gene coding for insulin.

During gene expression, transcription takes place in the _____ of the cell while translation takes place in the _____.

nucleus; cytoplasm

First described by Jacob and Monod, a(n) __________ is a group of genes and the DNA sequences that control their transcription.

operon

A group of genes and the DNA sequences that control their transcription are known as _______.

operons

Which of the following are found in all DNA nucleotides?

phosphate; nitrogen-containing base

anticodon

portion of the tRNA undergoing complementary binding with the codon

During mRNA __________ , a cap and poly-A tail are added, introns are removed, and the exons are then joined together.

processing

In prokaryotes, RNA polymerase binds to a short sequence of DNA called the _____.

promoter

The process by which new DNA nucleotides are added to the existing DNA chain using the enzyme DNA polymerase is called DNA

replication

A protein that binds to the operator, thus shutting down transcription of the gene, is termed a(n)

repressor

The site of protein synthesis in the cytoplasm is the

ribosome or polyribosome

During translation, which structure will carry the amino acids to the ribosome?

tRNA

In cats, the alleles for black or orange coat color are carried on the X chromosome. In female cats heterozygous for black/orange coat color, the coat color is patchy, showing black patches in some places and orange patches in others. What is the best explanation for this coloring?

the random inactivation of one of the two X chromosomes in all cells

DNA-binding proteins that help RNA polymerase bind to a promoter in eukaryotic cells are called

transcription factors

Polypeptides are created during which process?

translation

The process of ___________ uses mRNA, tRNA, and ribosomes to synthesize proteins.

translation