Biology 1001 Ch 12-14
Suppose ENZ-1 and ENZ-2 are two different restriction enzymes. If various pieces of DNA from different species are cut with these enzymes (as follows), which would most easily form recombinant molecules? (A) human DNA cut with ENZ-1 and gorilla DNA cut with ENZ-2 (B) human DNA cut with ENZ-1 and human DNA cut with ENZ-2 (C) human DNA cut with ENZ-2 and bacterial DNA cut with ENZ-2 (D) bacterial DNA cut with ENZ-1 and gorilla DNA cut with ENZ-2 (E) NONE OF THE ABOVE
(C) Human DNA cut with ENZ-2 and bacterial DNA cut with ENZ-2
What are the three steps of initiation?
1) A pre-initiation complex forms, consisting of the small ribosomal subunit and a methionine tRNA 2) The UAC anticodon of the methionine tRNA binds the mRNA molecule by base-pairing with the AUG start codon at the beginning of the mRNA 3) The two ribosomal subunits attach together, holding the mRNA between them ("threading a needle")
What are the three steps of translation?
1) Initiation 2) Elongation 3) Termination
Describe the six steps or elongation.
1. A second tRNA anticodon base-pairs with the second codon on the mRNA 2. A peptide bond is formed between methionine and the amino acid attached to the second tRNA 3. The "empty" tRNA is released and the ribosome moves down the mRNA one codon 4. A 3rd tRNA, with an anticodon complementary to the 3rd codon of the mRNA base-pairs with mRNA 5. This tRNA attaches its amino acid to the previous one using a peptide bond 6. This process continues, one codon at a time, until a stop codon (UAA, UAG, or UGA) is reached
What are the five categories that mutations can fall under?
1. Inversions 2. Translocations 3. Deletions 4. Insertions 5. Substitutions
In eukaryotic cells, transcriptional regulation occurs on at least three levels. What are the three levels? Describe each of them.
1. The individual gene Increasing or decreasing gene activity 2. Regions of chromosomes Condensed or tightly wound regions of DNA can make genes inaccessible to RNA polymerase Large parts of chromosomes may be inactivated preventing transcription 3. Entire chromosomes In female mammals, one entire X chromosome is condensed These "Barr bodies" were discovered by Murray Barr
Describe the four steps of termination
1. When the ribosome reaches a stop codon in the mRNA molecule, releasing factors cause it to release 2. The completed peptide chain, mRNA and ribosomal subunits no longer associate together(bc its reached a stop codon) 3. The is no amino acid associated with the tRNA reaching the stop codon 4. (this process results in)A sequence of amino acids (protein)
Which of the following contains deoxyribose? 1) Ribosomal RNA 2) DNA 3) Messenger RNA 4) Transfer RNA 5) RNA polymerase
2) DNA
How many bases are in a codon?
3
How many nucleotides does the genetic code use to specify an amino acid?
3
Suppose one strand of a "mini-gene" has the base sequence TACCCGGATTCA. If we assume no introns are involved, how many amino acids does the polypeptide encoded by this gene have?
4
Which of the items below is NOT directly involved in translation? 1) Ribosomes 2) tRNA 3) Amino acids 4) DNA 5) mRNA
4) DNA
Which of the following is TRUE regarding gene expression? 1) Gene expression remains constant throughout an organism's life span 2) Different individuals of the same species express all of the same genes 3) Gene expression is not influenced by the environment 4) Different tissues within an organism express different genes 5) NONE of the above answers
4) Different tissues within an organism express different genes
Which of the following is currently used by the U.S. Department of Justice as a form of genetic "fingerprints" of criminals? 1) The number of introns in a chromosome 2) The genes responsible for producing the unique patterns of swirls and loops on a person's fingers 3) Restriction fragment length polymorphisms (RFLPs) 4) Single tandem repeats (STRs) 5) Plasmids
4) Single tandem repeats (STRs)
Which of the following is NOT a means of regulating gene expression? 1) Regulating the life span of a protein 2) Modifying proteins after they are synthesized 3) Varying the rate at which messenger RNAs are translated 4) Varying the rate at which messenger RNAs are transcribed 5) Deleting genes from cells in which they are not needed
5) Deleting genes from cells in which they are not needed
All of the following are benefits of sequencing the human genome EXCEPT what? 1) genes were discovered whose functions were previously unknown. 2) more genes that cause disease have been discovered. 3) the number of genetic disorders that can be diagnosed with molecular techniques has increased. 4) better comparisons can be made between human genetics and the genetics of other organisms. 5) every genetic disorder is now curable or preventable.
5) Every genetic disorder is now curable or preventable
Of all the possible amino acids, all living organisms make use of only the same 20 amino acids. This supports the idea of what?
All living things are derived from a single common ancestor
A tRNA molecule brings ___________ to the ribosome during protein synthesis.
An amino acid
If you want to develop a procedure for identifying a genetic disorder caused by 20 different alleles, what method would be most likely to be useful?
Arrays of DNA probes on filter paper
What is the controlled breeding of domestic plants and animals by humans in order to produce certain physical traits in those organisms called?
Artificial selection
Imagine that it is 1965 and the bacterium Thermus aquaticus has not yet been discovered. As a geneticist interested in forensics applications, you are attempting to develop a gene-amplifying technique similar to PCR. In a test tube, you place a DNA sample, free nucleotides, human DNA polymerase, and the appropriate primers for the DNA sequence being analyzed. You first heat the sample to 90°C, then cool it to 50°C, and then reheat it to 70°C. Based on this scenario and your knowledge of how modern PCR works, the result of these procedures will be what? (A) successful copying of the DNA, because it follows modern PCR procedures almost perfectly. (B) unsuccessful, because the enzyme will denature during the first step (heating). (C) unsuccessful, because the enzyme will denature during the second step (cooling). (D) unsuccessful, because the enzyme will denature during the third step (reheating). (E) unsuccessful, because human DNA polymerase cannot recognize the primers used.
B) Unsuccessful, because the enzyme will denature during the first step (heating)
______ is the modification of organisms, cells, or molecules to produce food, drugs, or other goods.
Biotechnology
For years, the residents of a small Mexican town complained about large numbers of flies coming from a nearby hog farm, where millions of pigs are raised each year. In 2009, the majority of residents in this town became sick with "swine flu," caused by the H1N1 influenza virus. This virus infects people but is apparently genetically similar to a virus that infects hogs. The virus has since gone on to infect (and, in some cases, kill) people in Mexico City, has quickly spread around the entire planet, and has been declared a global pandemic. Based on this scenario and your knowledge of genetics, this virus is most likely what? (A) inappropriately called the "swine flu" virus and is merely coincidentally similar to a virus that infects pigs. (B) a genetically unmodified virus that first infected pigs, then flies, then people. (C) a human virus that was transformed within the bacteria living in pig manure and can now infect pigs and humans. (D) the result of a hog-specific virus being transformed into a human-specific virus, after being carried from the hog farm to people via flying insects. (E) the first known example of a genetically modified virus that could potentially cause millions of people to die or perhaps the extinction of humans altogether.
C) A human virus that was transformed within the bacteria living in pig manure and can now infect pigs and humans
What do proteins control?
Catalysis, Structure, Regulation
Triplets of RNA bases that are read by the ribosome
Codons
Who proposed the geological theory of catastrophism?
Cuvier
Which of the following is NOT a valid difference between traditional and modern forms of biotechnology? (A) Modern biotechnology can isolate and manipulate individual genes. (B) Traditional biotechnology is almost always limited to genetic recombination between individuals of one species or two closely related species. (C) Traditional biotechnology cannot produce entirely new genes in one step. (D) Modern forms of biotechnology are slower than traditional forms of biotechnology. (E) NONE OF THE ABOVE
D) Modern forms of biotechnology are slower than traditional forms of biotechnology
Which of the following is NOT an example of genetic recombination between different species in nature? (A) bacterial transformation (B) bacteria that acquire foreign plasmids (C) viruses that transfer DNA between host organisms (D) sexual reproduction (E) NONE OF THE ABOVE
D) Sexual reproduction
What are the three ways in which RNA differs from DNA?
DNA - Double Helix RNA - Straight DNA - Thymine RNA - Uracil DNA - Double Strand RNA - Single Strand DNA - Deoxyribose Sugar RNA - Ribose Sugar
______ uses free nucleotides to create complementary strands.
DNA Polymerase
______ are short, single-stranded DNA fragments used to identify DNA in a gel pattern.
DNA Probes
DNA samples run on STR gels produce a pattern, called a ______.
DNA Profile
Who wrote On the Origin of Species by Means of Natural Selection?
Darwin
Who presented the idea of natural selection to the Linnaean Society in 1858?
Darwin and Wallace
Occurs when one or more nucleotides are removed from the gene sequence
Deletion
Why does your tongue not grow hair?
Different genes are expressed in different tissues
Which of the following supports the idea that all organisms share a common ancestry? (A) All cells use DNA as a cellular energy carrier. (B) All cells use ATP as the template for protein synthesis. (C) All cells use the same collection of lipids. (D) All cells use amino acids as a carrier of genetic information. (E) All cells have a similar biochemistry, including amino acids, nucleic acids, and ATP.
E) All cells have a similar biochemistry, including amino acids, nucleic acids, and ATP.
Which of the following is NOT used for biotechnology? (A) producing large quantities of particular human proteins (B) producing effective and safe vaccines (C) identifying human fetuses with particular genetic diseases (D) altering food plants to increase yields (E) altering the intelligence levels of newborn infants
E) Altering the intelligence levels of newborn infants
Which of the following statements about mutations is TRUE? (A) Mutations have no effect on the survival and reproduction of an organism. (B) Mutations are almost always better for the organism. (C) Mutations almost always leave the organism worse off than before. (D) Mutations are caused by natural selection. (E) Mutations occur at random and are by chance.
E) Mutations occur at random and are by chance
How does DNA provide information for protein synthesis?
Each set of 3 bases in a DNA molecule codes for a specific amino acid in a protein
A mutation that results in a change in the codon reading pattern could result from what?
Either an insertion or a deletion of a base
Regions that code for a protein
Exons
True or False. Deletions and insertions of three nucleotides (or a multiple of three) do not cause a frameshift.
False
True or False. During translation, mRNA, double-stranded DNA, and single-stranded DNA cooperate to synthesize proteins.
False
True or False. Mutations will always change amino acid sequences of the protein.
False
True or False. Point mutations never have drastic results.
False
tRNA is necessary for transcription to occur. True or False?
False
Mutations that result from the insertion of deletion of nucleotides within the coding sequence in non-multiples of 3; alter the reading frame of the mRNA that is translated into amino acids
Frameshift Mutations
If a tRNA molecule that is specialized for the transfer of the amino acid valine has the anti-codon CAG, it will couple with which codon?
GUC
______ is a technique used to spread out DNA fragments of varying lengths in a mixture.
Gel Electrophoresis
Messenger RNA, tRNAs carrying amino acids, and a ribosome, synthesizes a protein in this process
Genetic Code
More modern uses modify the genes directly through ______.
Genetic Engineering
Natural selection can act on a certain trait only if the trait is what?
Heritable
Assume it is possible to remove continuous cores of rock from Earth that are 3,000 feet long and contain fossils. What would the theory of evolution by natural selection predict about the fossils found in such cores as they are examined from top to bottom?
Higher fossils are more similar to living species than lower fossils
If the weather in Virginia changed so dramatically that there was snow on the ground most of the year, what would occur in the local squirrel population?
If a mutation occurred that caused white fur to develop, such white squirrels would likely survive and reproduce better than gray squirrels
Occurs when one or more nucleotides are added to the gene sequence
Insertion
Spacer regions between genes
Introns
______ and ______ occur when pieces of DNA are broken apart and re-attached, within a single chromosome or to a different chromosome.
Inversions and Translocations
The concept that Earth's present landscape is due to gradual geologic processes was proposed by whom?
Lyell
Which geologist described the age of the Earth as "eternal"?
Lyell
Mutations that replace one amino acid with another
Missense Mutations
Changes in the base sequence of DNA caused by mistakes during replication or by various environmental factors
Mutations
Mutations that introduce a STOP codon
Nonsense Mutations
Mutations that may or may not change amino acid sequences of the protein.
Nucleotide Substitutions
What technique amplifies a specific region of DNA?
PCR
This DNA could be part of a chromosome from another bacterium or tiny circular DNA molecules called ______.
Plasmid
______ produces virtually unlimited copies of a very small DNA sample.
Polymerase Chain Reaction (PCR)
PCR requires a small piece of DNA called ______.
Primers
Area at the beginning of a gene that RNA polymerase binds to
Promoter Region
Intermediary that carries DNA information from the nucleus to the cytoplasm
RNA
Genetic variations in natural populations develop due to what?
Random mutations of the DNA
DNA that has been altered to contain genes or portions of genes from different organisms is called ______.
Recombinant DNA
If homologous chromosomes have different alleles, they may produce different numbers of fragments, when cut by restriction enzymes. These differences, called ______, can be detected, and the patterns observed can be used to diagnose the presence or absence of various alleles.
Restriction Fragment Length Polymorphisms (RFLPs)
Forensic scientists use small, repeating segments of DNA, called ______, with astonishing accuracy to identify people.
Short Tandem Repeats (STRs)
Mutations that do not alter the amino acids specified
Silent (neutral) Mutations
Charles Darwin believed that artificial selection was what?
Similar in many ways to natural selection
Which of the four postulates of Darwin's theory of evolution was not well established when On the Origin of Species was first published but is overwhelmingly supported today?
Some differences among individuals in a population are due to genetics and are heritable.
Each mRNA has two things. What are they?
Start Codon and Stop Codon
The staggered cut leaves a short section of single-stranded DNA at each end. These unpaired sections are called "______."
Sticky Ends
An organism that contains foreign DNA, which was inserted into its own genetic material, is called what?
Trangenic
Information in a DNA gene is copied into messenger RNA in this process
Transcription
In ______, bacteria pick up pieces of DNA from the environment.
Transformation
Plants and animals that express DNA that has been modified or derived from other species are ______ or ______.
Transgenic or Genetically Modified Organisms (GMOs)
Translates the nucleotide sequence into amino acids in proteins
Translation
What is the manufacturing of proteins from RNA and amino acids referred to as?
Translation
What is the process of converting the "message" of mRNA into a sequence of amino acids called?
Translation
In nature, DNA recombination occurs but it is random and undirected. True or False?
True
Messenger RNA is single-standed. True or False?
True
Sexual reproduction is an example of DNA recombination. True or False?
True
The discovery of the organism Thermus Aquaticus was critical for the development of the technique of PCR. True or False?
True
True or False. Mutations create new gene sequences and are the ultimate source of genetic variation.
True
Suppose the template DNA strand of a "mini-gene" has the base sequence TACCCGGATTCA. The anti-codon of the tRNA that carries the first amino acid to the ribosome will be what?
UAC
In recombinant DNA technology, what are plasmids used for?
Used to insert foreign DNA into bacteria
How many codons are amino acids specified by?
as many as 6
Carries DNA gene information to the ribosome
mRNA
What are the three types of RNA involved in protein synthesis, and what do they do?
mRNA - makes a copy of DNA and carries the copy from the nucleus to the cytoplasm so that the information can be used to make a protein tRNA - transfers amino acids to ribosomes for protein synthesis rRNA - controls ribosome formation in the cytoplasm
How many amino acids does each codon code for?
one
Part of the structure of ribosomes; each ribosome consists of two subunits—one small and one large
rRNA
Carries amino acids to the ribosomes for addition to the growing protein; have a "cloverleaf" shape
tRNA
What two things decode codons?
tRNA and Ribosomes
