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Prentice Hall Biology Chapter 12 - DNA and RNA
Terms in this set (80)
What did Frederick Griffith want to learn about bacteria?
How certian types of bacteria produce a serious disease known ad pneumonia.
The strain of bacteria that caused pneumonia grew into what kind of colonies on culture plates?
What result of Griffith's experiment suggested that the cause of pneumonia was not a chemical poison released by the disease-causing bacteria?
He hears the bacteria to kill the mice injected the heat-killed bacteria into the mice and they survived
The process in which one strain if bacteria is changed by a gene or genes from another strain of bacteria
* Avery and other scientists discovered that the _______ acid ______ stores and transmits the genetic information from one generation of an organism to the next.
nucleic acid DNA
What hypothesis did Griffith form from the results of his experiments?
When the live, harmless bacteria and the heat-killed bacteria were mixed some factor was transferred from the heat-killed cells into the live cells
Describe how Avery and his group determined which molecule was most important for transformation?
Avery created an extract with the bacteria and treated it with enzymes to kill lipids, carbs, RNA, and other molecules, then transformation did not occur.
Transformation is not occur when what was destroyed?
What was the conclusion from Avery's experiment?
The nucleic acid DNA stores and transmits the genetic information from one generation of an organism to the next.
One kind of virus that infects bacteria
What happens when a bacteriophage infects a bacterial cell?
The virus attaches to the surface of the cell and injects it's genetic information into it. The viral genes act to produce many new bacteriophages they slowly destroy the bacterium.
How would Hershey and Chase learn whether genes were made of protein or DNA?
They grew viruses in cultures containing radioactive isotopes of Sulfur 35 and Phosphorus 32.
What results did Hershey and Chase observe?
Nearly all the radioactive in the bacteria was from Phosphorus 32, the marker found in DNA
* Hershey and Chase concluded that the genetic material of the bacteriophage was...
DNA not protein
Three critical things that genes are known to do...
1. Genes have to carry information from one generation to the next.
2. They had to put that information to work by determining the heritable characteristics of an organism.
3. Genes have to be easily copied, because all of a cells genetic information is replicated everything a cell divides.
What is the makeup of a nucleotide?
5-carbon sugar called deoxyribose, a phosphate group, and a nitrogenous base.
Four kinds of nitrogenous bases found in DNA are...
Adenine, guanine, cytosine, and thymine.
What forms the backbone of a DNA chain?
Sugar and phosphate groups each of nucleotides
How did Francis Crick and James Watson try to understand the structure of DNA?
By building a 3-D model of the molecule made of cardboard and wire.
How did Watson and Crick describe the structure of DNA?
As a double helix with two strands that wound around each other.
The location of DNA in prokaryotic cells.
Where in eukaryotic cells is DNA generally located in the form of a number of chromosomes?
Eukaryotic chromosomes contain both DNA and proteins, packed together to form...
Chromatin consists of DNA that is tightly coiled around proteins.
Why are individual chromosomes visible only during mitosis?
Fibers of each individual chromosome are drawn together, forming the tightly packed chromosomes you can see through a light microscope in dividing cells.
What do nucleosomes do?
Able to fold enormous lengths of DNA into tiny space in the cell nucleus.
What occurs during the process of replication?
A cell duplicates its DNA in a copying process.
The sites where DNA replication and separation occur.
What occurs when a molecule of DNA is "unzipped"?
Hydrogen bonds between the base pairs are broken and the two strands of the molecule unwind.
Two major roles of DNA polymerase in the process of DNA replication are...
1. Joins individual nucleotides to produce a DNA molecule (polymer)
2. "Proofreads" each new DNA strand, helping to maximize the offs that each molecule is a perfect copy do the original DNA.
Three main differences between DNA and RNA are...
1. The sugar in the RNA is ribose instead of deoxyribose
2. RNA is generally single stranded
3. RNA contains urial in place of thymine
What is the importance of the cells ability to to copy a single DNA sequence into RNA?
Makes it possible for a single gene to produce hundreds or thousands of RNA molecules.
What is the one job in which most RNA molecules are involved?
mRNA: carries copies of the instructions for assembling amino acids from DNA to the rest of the cell
rRNA: type of RNA that makes up the major part of ribosomes
tRNA: transfers each amino acid to the ribosome to help assemble proteins
Two explanations for why some RNA molecules are cut and spliced are...
1. Makes it possible for a single gene to produce several different forms of RNA
2. Play a told in evolution, small changes in DNA sequences can effect gene expression
Proteins make by joining amino acids into long chains
Three consecutive nucleotides that specify single amino acids that is to be added to the polypeptide
Number of possible three-base codons...
What occurs during translation?
The cell uses information from mRNA to produce proteins
Translation takes place on...
Many proteins are _______, which catalyze and regulate chemical reactions
Changes in genetic material
Mutations that occur at a single point in the DNA sequence
A mutation involving the insertion or deletion of a nucleotide
Invoke the loss of all or part of a chromosome
Produce extra copies of parts of a chromosome
Part of a chromosome becomes oriented in the reverse of its usual direction
Part of one chromosome breaks off and attaches to another
Mutations that cause dramatic changes in protein structure are often what?
Mutations are a source of _______ ___________ in a species.
The condition which an organism has extra sets of chromosomes
Where do RNA polymerase bind?
A group of genes that operate together
What is the function of the genes in the lactose operon?
To profuse proteins to allow E. Coil to digest lactose
What turns the lactose on and off? What do they bind to?
On- by the presence of lactose binds to repressors
Off- by repressors binds to operators
How does the repressor protein prevent transcription?
Blocks the RNA polymerase from being able to preform transcription
How does lactose cause the lac operon to turn on?
Binds of the repressor causing it to release from the operator
How are eukaryotic genes usually controlled?
Individually and have regulatory sequences that are much more complex than those of lac operon
What is the function of the TATA box?
Helps position RNA polymerase by making a point at which transcription begins
Three ways in which proteins that bind to enhancer sequences of a gene can work to regulate gene expression are...
1. Enhance transcription by opening up tightly packed chromatin
2. Help to attract RNA polymerase
3. Block access to the genes
Why is gene regulation in eukaryotic more complex than in prokaryotes?
Cell specialization require production if larger variety of proteins, genetic code turned off cells have many jobs
What role do the hox genes play in the development of an organism?
Control the differentiation of cells and tissues in the embryo. (Control development and specialization)
Hydrogen bonding between adenine and thymine
Unit of DNA
Sequence in mRNA that is cut out
DNA sequence that binds RNA polymerase
Cells specializing in structure and function
Making a protein using mRNA
The duplication of DNA is called what?
The principle enzyme involved in DNA replication is what and why?
DNA polymerase because it joins individual nucleotides to produce a DNA molecule
DNA sequences that code from proteins
Differentiation of cells and tissues in the embryo is controlled by this
The complementary bases to the one mRNA codon
Enzyme similar to DNA polymerase that binds to DNA and separates the DNA strand during transcription
What are bacteriophages composed of?
DNA or RNA core and a protein coat
What nitrogen bases go together?
Adenine = thymine
Guanine = cytosine
This is an example of Chargaff's Rule
Used x-ray diffraction to get information of the DNA molecule. Her x-ray showed the x-shaped pattern of DNA.