Chapter 12

List in sequential order the steps leading to transcription during transcriptional control of eukaryotic genes. Place the first step on the top of the list.

1. Transcription factors bind to promoters 2. Transcription activators bind to enhancers 3. Mediator proteins bind transcription activators to transcription factors. 4. RNA polymerase begins transcribing.

A certain gene excerpt has the sequence AAGGGTAACGA, then changes to CCGGGTAACGA. What just happened?

Correct Answer A gene mutation

The DNA sequence AAGTCTCAGGTC undergoes a point mutation. Which of the following could be the new sequence of DNA?

Correct Answer AAGTCTCTGGTC

A dark-staining portion of female, mammal nuclei containing an inactive X chromosome is called a:

Correct Answer Barr body

Identify the group of mammals that have a lower expression of immune system genes.

Correct Answer Bats

The first step of transcriptional control requires the presence of

Correct Answer Blank 1: DNA

A carcinogen is a type of mutagen that leads to the development of

Correct Answer Blank 1: cancer

Mutagens that leads to the development of cancer are called

Correct Answer Blank 1: carcinogens

Identical twins , having the same DNA can have different gene expression. The difference in gene expression in twins is due to __________ inheritance.

Correct Answer Blank 1: epigenetic , epigene, epi-genetic, or epigenes

Chromatin that is extended and transcribable is called

Correct Answer Blank 1: euchromati

Expressed regions of a mRNA that are conserved during mRNA processing are called

Correct Answer Blank 1: exons

Since it is highly condensed and inaccessible to RNA polymerase, the type of chromatin called _________ is seldom or never transcribed.

Correct Answer Blank 1: heterochromatin

The highly compacted chromatin that is not accessible for transcription is called

Correct Answer Blank 1: heterochromatin

An organism living in an environment free of mutagens would never experience

Correct Answer Blank 1: induced

Environmental influences, like toxic chemicals or radiation, are said to cause

Correct Answer Blank 1: induced

The noncoding regions, which are excised before the formation of mRNA, are called

Correct Answer Blank 1: introns

Chemical or physical agents that increase the chance of mutation are called

Correct Answer Blank 1: mutagens

Environmental factors such as radiation and organic chemicals can affect the nucleotide base composition of DNA and are therefore referred to as

Correct Answer Blank 1: mutagens or carcinogens

A permanent change to the base sequence of DNA is known as a gene

Correct Answer Blank 1: mutation

Posttranscriptional control takes place in the cell

Correct Answer Blank 1: nucleus or nuclei

Promoters, operators, and structural genes are the components of a(n)

Correct Answer Blank 1: operon

The functional unit of structural and regulatory prokaryotic genes is known as the

Correct Answer Blank 1: operon

When one base in a DNA sequence is altered, it is known as a

Correct Answer Blank 1: point

he enzyme that will carry out replication, proofread the new strand, and detect any mismatched nucleotides is DNA

Correct Answer Blank 1: polymerase

The stringy material called chromatin is composed of DNA and its associated

Correct Answer Blank 1: proteins or histones

The control of gene expression in cells is achieved through the process of gene

Correct Answer Blank 1: regulation

Gene mutations that occur during normal biological processes such as movement of transposons of DNA replication are called

Correct Answer Blank 1: spontaneous

Uncontrolled cell division and tumors can be caused by a mutation in the tumor

Correct Answer Blank 1: suppressor

Proteins that help regulate transcription by assisting the binding of RNA polymerase to the promotor are known as ______ factors.

Correct Answer Blank 1: transcription

The most critical of the five levels of eukaryotic gene expression control is

Correct Answer Blank 1: transcriptional or transcription

The level of eukaryotic control of gene expression that involves the control of the mRNA transcript in the cytoplasm of the cell is called ________ control.

Correct Answer Blank 1: translational or translation

The protein complex that not only assists with DNA replication, but also has the ability to repair spontaneous mutations is called ________.

Correct Answer DNA polymerase

Which of the following forms of chromatin would take up the most linear space (assuming same number of bases for each)?

Correct Answer Euchromatin

True or false: Lactose metabolism in E. coli is carried out by one enzyme product of one operon.

Correct Answer False

Which of the following is the most tightly packed chromatin?

Correct Answer Heterochromatin

Which set of genes have a lower expression in bats compared to other mammals? Multiple choice question. Blood type Fur color Immune system Developmental

Correct Answer Immune system

Which of the following is the last chance of influencing gene expression?

Correct Answer Posttranslational control

Which of the following would NOT be present in condensed eukaryotic chromatin?

Correct Answer RNA polymerase

Select the proteins that are required for the initiation of transcription by RNA polymerase in eukaryotes?

Correct Answer Transcription activator Transcription factor

Which of these levels of eukaryotic gene control occurs at the chromatin structure in the nucleus?

Correct Answer Transcriptional control

True or false: Although there are various levels of genetic control, transcriptional control is the most critical.

Correct Answer True

True or false: Gene regulation occurs in both prokaryotic cells and eukaryotic cells.

Correct Answer True

Which of the following have roles in transcriptional control of eukaryotic genes?

Correct Answer activators transcription factors DNA repressors

Chromatin structure helps control gene expression by:

Correct Answer allowing access to the DNA when it is not compacted

Which of the following are activities of posttranscriptional control mechanisms?

Correct Answer alternative mRNA splicing control of mRNA nuclear export speed

The structural genes found on the lac operon function to

Correct Answer break down lactose.

The DNA and its associated proteins are called

Correct Answer chromatin

Translational control occurs in the _____ of eukaryotic cells.

Correct Answer cytoplasm

The protein products of a certain bacterium depend upon its: Multiple choice question. introns exons environment abundance

Correct Answer environment

The transmission of genetic information outside of the coding sequence of a gene is referred to as ______.

Correct Answer epigenetic inheritance

Functional proteins are created from mRNA transcripts containing only:

Correct Answer exons

Barr bodies are normally present in

Correct Answer female mammals.

Small RNA is used to influence ______.

Correct Answer gene regulation

When the activators, enhancers, and mediators come in contact with the transcription factors the DNA forms a shape called a ______.

Correct Answer hairpin loop

When miRNA and siRNA molecules inhibit normal gene expression, RNA _______ has occurred.

Correct Answer interference

Heterochromatin is not transcribed because ______.

Correct Answer it is inaccessible to RNA polymerase.

Introns, noncoding regions, are excised before the exons are joined together to form ______.

Correct Answer mRNA

RNA interference occurs when ______ molecules interfere with normal gene expression.

Correct Answer miRNA and siRNA

A mutation that results in one base in the DNA being replaced by a different base is called a

Correct Answer point mutation.

Regulation that controls the way mRNA transcripts are processed in the nucleus called

Correct Answer posttranscriptional

Regulation that controls the way mRNA transcripts are processed in the nucleus called ________ control.

Correct Answer posttranscriptional

Alternative mRNA splicing takes place at which level of eukaryotic gene control?

Correct Answer posttranscriptional control

The level of eukaryotic control of gene expression that involves how a protein product is handled in a cell is called

Correct Answer posttranslational

Operons are generally involved with ______.

Correct Answer prokaryotic gene expression

Repressible operons require which of the following? Multiple select question. lactose enhancer repressor corepressor

Correct Answer repressor corepressor

Which of the following is formed from the DNA that is not used in transcription of a protein?

Correct Answer sRNA

If a mutation arises during DNA replication, then the mutation would considered a(n)______________ mutation.

Correct Answer spontaneous

An operon includes

Correct Answer structural genes operator promoter

Which of the following is an example of a repressible operon?

Correct Answer trp operon

The protein that restricts mitosis is coded for by the _______ gene.

Correct Answer tumor suppressor

Which of these levels of eukaryotic gene control is the most critical?

Transcriptional

True or false: Bacteria produce the same protein products regardless of their environment.

fALSE