Introduction To Biology Chapter 11

Discipline: Biology (and other Life Sciences)

Type of Paper: Question-Answer

Academic Level: Undergrad. (yrs 3-4)

Paper Format: APA

Pages: 1 Words: 275


    Introduction To Biology Chapter 11

The operon model of the regulation of gene expression in bacteria was proposed by _____.   Jacob and Monod 

Regulatory proteins bind to _____.   the operator  
Which of these is NOT a component of the lac operon?
  • lactose-utilization genes only
  • promoter only
  • regulatory gene only
  • operator only
  • promoter and operator       The regulatory gene, while not a part of the operon, plays a role in regulating the expression of the genes of the operon.

  •   In the presence of a regulatory protein the lac operon is _____. not transcribed  The regulatory protein of the lac operon is a repressor.   

Summarize chromosome packing 

Which of these indicates an enhancer region?  A

Which of these directly bind(s) to the promoter?   C & D 

The process of transcription is indicated by the letter _____.  A
  • Transcription is the process by which information encoded in DNA is converted to information encoded in RNA.

The letter E is indicating a process of gene expression that involves _____.   protein breakdown

RNA processing is indicated by the letter _____.  B
  • As you can see, introns have been removed and a cap and a tail added to the RNA molecule.

Enzyme complexes that break down protein are called _____.     Proteasomes are enzyme complexes that break down proteins.

The nuclear membrane's role in the regulation of gene expression involves _____.     regulating the transport of mRNA to the cytoplasm    
What is the function of a spliceosome?     RNA processing

Protein-phosphorylating enzymes' role in the regulation of gene expression involves _____.    protein activation

Describe DNA microarray analysis

What is a second messenger?    A small, nonprotein, water-soluble molecule or ion, such as calcium ion or cyclic AMP, that relays a signal to a cell's interior in response to a signal received by a signal receptor protein.

Which of these acts as a second messenger? 

Which of these is responsible for initiating a signal transduction pathway?    The signal molecule. The attachment of a signal molecule to a plasma membrane receptor initiates a signal transduction pathway.

What role does a transcription factor play in a signal transduction pathway?   By binding to DNA it triggers the transcription of a specific gene.    
A signal transduction pathway is initiated when a _____ binds to a receptor.  signal molecule

Calcium ions that act as second messengers are stored in _____.   endoplasmic reticula

_____ catalyzes the production of _____, which then opens an ion channel that releases _____ into the cell's cytoplasm.    Phospholipase C ... IP3 .... Ca2+
  • Phospholipase C cleaves IP3 from a membrane protein, and IP3 then binds to a calcium channel on the ER.

  • A protein kinase activating many other protein kinases is an example of _____.  Amplification
  • By activating many other molecules the initial signal is amplified.   
A normal gene that if mutated can lead to cancer    Proto-oncogene 

A gene that causes a cell to become cancerous is called  oncogene
A ______ is a gene that encodes proteins that inhibit cell division. Such proteins normally help prevent cells from becoming cancerous.   Tumor-supressor gene 

A ______ is a protein that promotes cell division. In excess such a protein may lead to cancer.   Growth Factor

Which of these is NOT a carcinogen?
  • UV light
  • cigarette smoke
  • fat
  • testosterone
  • all of the above are carcinogens   all of the above are carcinogens

Which of the following does NOT accurately describe the lac operon?  
  • regulated   eukaryotic controls the uptake and use of a specific sugar
  • inducible   eukaryotic This statement is true. The lac operon is normally "off" but can be induced (turned on) in the presence of the sugar lactose.

  In prokaryotes, a group of genes with related functions that are organized and regulated as a group is called __________.   an operon
  • An operon is a group of structural genes with related functions.
molecule D

The lac operon in Escherichia coli does what?    prevents lactose-utilizing enzymes from being expressed when lactose is absent from the environment.    

There is a mutation in the operator of the lac operon in a cell such that the lac repressor always stays bound to the operator. If lactose is added to the cell, what will happen?   Lactose will bind to the repressor, and lac enzymes will not be produced.

What controls the way in which a zygote differentiates?      Selective genes are turned on and off, depending on the fate of the cell.    
  •  The particular genes that are active in each type of differentiated cell are the source of its particular function and structure.

Cells become specialized by a process known as _____.   Differentiation
  • During embryonic development, cells undergo differentiation. As a result, they become specialized in both structure and function.

  In eukaryotic cells, several proteins are involved in the process of transcription. This process involves enhancers that are _____.   Bound by activators, causing DNA to bend   The bound activators can then interact with other transcription factor proteins and bind as a complex at the gene's promoter.  
  In eukaryotes, gene expression is regulated mostly by _____.   controlling the transcription of genes    In eukaryotes most gene expression is regulated by controlling transcription, either through the use of activators (inducing) or silencers (inhibiting).

Small pieces of RNA that can regulate translation of mRNA are called  microRNA.