Biology 101 Ch. 11 Quiz

enhancers

A DNA sequence that recognizes certain transcription factors that can stimulate transcription of nearby genes.

repressor

A protein that suppresses the transcription of a gene.

operator

Region of DNA that controls RNA polymerase's access to a set of genes with related functions. (yellow)

Visualizing Gene Expression

Researchers can visualize which genes are active in which tissues using a variety of techniques, including probes and DNA microarrays

More people die of ______ cancer than of any other cancer.

lung

reproductive cloning of animals equation

nucleus from donor cell -> early embryo resulting from nuclear transplantation -> embryo implanted in surrogate mother -> clone of nucleus donor

The lac operon is shown in the accompanying figure. Answer the following question after reviewing the figure. The lac operon is usually in the ______ position and is activated by ______.

off... lactose

What name is given to a gene that causes cancer?

oncogene

In an operon, the ______ acts as an on/off switch.

operator

In bacteria, what name is given to a cluster of genes with related functions, along with their DNA control sequences?

operon

DNA microarray

-used to study gene expression 1. mRNA is isolated and converted to fluorescently labeled, ss cDNA 2. Molecules allowed to hybridize 3. Locations of the labeled cDNA molecules can be detected with computerized scanner -genes to which cDNAs hybridize are the ones the organism is expressing

How can a mutation in just one homeotic gene drastically affect an organisms physical appearance?

Because homeotic genes, a single change can affect the expression of many proteins that control appearance

RNA interference

Blocking gene expression by means of an miRNA silencing complex.

transcription factors

Collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription.

What is the first level of control of eukaryotic gene transcription?

DNA packing and unpacking

What is a difference between embryonic and adult stem cells?

Embryonic stem cells are undifferentiated; adult stem cells are partially differentiated.

homeotic genes

Evidence for the exolutionalry importance of gene regulation is apparent in homeotoic genes that regulate other genes that turn control emryonic development

genetic potential of cells

Most differentiated cells retain a complete set of genes, so an orchid plant can be made to grow from a single orchid cell. Under controlled conditions, animals can also be cloned

Repressors act by blocking the binding of _____ to the operator.

RNA polymerase

How is it that the cells in different body tissues are able to perform different functions?

The cells exhibit different patterns of gene expression.

signal transduction pathway

The process by which a signal on a cell's surface is converted into a specific cellular response.

gene expression

The process by which information encoded in DNA directs the synthesis of proteins or, in some cases, RNAs that are not translated into proteins and instead function as RNAs.

How can a single RNA transcript be translated into different polypeptides?

There is more than one way to splice an RNA transcript.

______ is(are) responsible for more cancers than any other carcinogen.

Tobacco

reproductive cloning of animals

Using a somatic cell from a multicellular organism to make one or more genetically identical individuals.

Cell signaling (header)

Within a multicellular organism, information must be communicated between cells

Which of these lifestyle choices will increase cancer risk?

a diet low in plant fiber

The figure below illustrates ______.

alternative RNA splicing

Homeotic genes ______.

are evidence of the common ancestry of eukaryotic organisms

At one point, you were just an undifferentiated, single cell. You are now made of many cells; some of these cells function as liver cells, some as muscle cells, some as red blood cells, while others play different roles. What name is given to the process that is responsible for this?

cellular differentiation

Which of these plays a role in the regulation of transcription in both prokaryotic and eukaryotic cells?

attachment of RNA polymerase to the promoter

While examining a human cell that functions normally, you determine that it has 45 functional chromosomes and one chromosome that is almost completely inactive. You immediately decide that it is very likely that this cell ______.

came from a normal human female

Many proto-oncogenes regulate ______.

cell division

alternate RNA splicing

different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exons and which as introns

The process by which genotype becomes expressed as phenotype is ______.

gene expression

operon

group of genes operating together

The "master control genes" that regulate other genes, which determine what body parts will develop in which locations, are called ______.

homeotic genes

silencers

inhibit transcription

hometoic genes (header)

interactions between cells of an embryo through chemical signals coordinate the process of development

cell signaling

key to the development and functioning of multicellular organisms. Signal Transduction pathways convert molecular messages to cell responses, such as the transcription of particular genes

Which of these is most likely to cause the development of a six-legged frog?

mutation of homeotic genes

Introns are ______.

noncoding DNA sequences

therapeutic cloning and stem cells (equation)

nucleus from donor -> early embryo resulting from nuclear transplantation -> embryonic stem cells in culture -> specialized cells

Bacterial RNA polymerase binds to the ______.

promoter

therapeutic cloning and stem cells

purpose: to produce embryonic stem cells for medical uses. embryonic, umbilical cord, and adult stem cells are show promise for therapeutic uses

Which of the following turns off transcription by binding to the operator?

repressor

Cells communicate with one another via ______.

signal transduction pathways

In eukaryotic cells, repressor proteins inhibit transcription by binding to ______.

silencers

microRNA

small single stranded RNA molecules that bind to mRNA and can degrade mRNA or block its translation.

Promoter

specific region of a gene where RNA polymerase can bind and begin transcription

Consider the following figure, which outlines cloning by nuclear transplantation. Why does the clone not resemble the surrogate mother?

the clone would exhibit characteristics of the genetic donor, not the surrogate.

Examine the figure below. In a typical colon cancer, the first step is ______.

the mutation of a proto-oncogene, producing an oncogene.

Possible uses of reproductive cloning include ______.

the production of genetically identical animals for experimentation the production of organs in pigs for transplant into humans restocking populations of endangered animals (all of the above)

gene regulation

the turning on and off of genes

Examine the figure below. The initiation of transcription requires that enhancers bind to _____.

transcription factors