Bio 1201 test 4

genetic code

the set of rules that convert a nucleotide sequence in RNA to an amino acid sequence.

Genomics

the study of complete sets of genes (genomes). the first targets of this research were bacteria, which have relatively little DNA

amino acid

At the other end of the tRNA molecule is a site where one specific kind of _______ _____ attaches.

In a DNA double helix, adenine pairs with ________ and guanine pairs with ________. A. cytosine, thymine B. thymine, cytosine C. guanine, adenine D. uracil, cytosine

B

Transcription is the ________. A. manufacture of two new DNA double helices that are identical to an old DNA double helix B. manufacture of a strand of RNA complementary to a strand of DNA C. modification of a strand of RNA prior to the manufacture of a protein D. manufacture of a protein based on information carried by RNA

B

Initiation

Brings together - mRNA - first amino acid with its attached tRNA - two subunits of the ribosome

STR analysis

a method of DNA profiling and compares the lengths of STR sequences at specific sites in the genome

A nucleotide is made up of the following 3 components ......

a nitrogen base, a sugar, and a phosphate group

Lytic cycle

how most phages enter a reproductive cycle once they infect a bacterium

transcription

process of protein synthesis in which genetic information is transferred from DNA into an RNA molecule

translation

process of protein synthesis in which genetic information is transferred from RNA into a polypeptide (protein strand)

Which of the following are constructed by scientists by combining pieces of DNA from two different sources/species to form a single DNA molecule? A. Recombinant DNA B. Short Tandom Repeats (STR) C. Exons D. Homeotic Genes

A

A virus is

- An infectious particle - a bit of nucleic acid wrapped in a protein coat - an envelope of membrane (in some cases)

Recombinant DNA techniques

- Bacteria are the workhouses of modern biotechnology - to manipulate genes in lab, bacterial plasmids are often used

Translocation (step 3 of elongation)

- P site tRNA leaves ribosome, ribosome moves the remainder tRNA, carrying the polypeptide, to the P site - mRNA and tRNA move as a unit - movement brings intro the A site the next mRNA codon to be translated

Peptide bond formation (step 2 of elongation)

- Polypeptide leave tRNA in the P site and attaches to the amino acid on the tRNA in the A site - ribosome creates a new peptide bond - chain now has one more amino acid

Prions can cause a number of brain diseases in various animal species

- Scrapie in sheep and goats - Chronic wasting disease in deer and elk - mad cow disease - Creutzfeldt-Jakob disease in humans

Bacterial plasmids

- Small, circular DNA molecules that duplicate separately from the larger bacterial chromosome - can carry virtually any gene and are passed from one generation of bacteria to next - are key tools for gene cloning

Genetic Engineering

- Using methods of DNA technology to modify specific genes and move them between organisms - direct manipulation of genes for practical purposes

Lysogenic cycle

- alternative reproduction route for viruses - DNA replication occurs without phage production or the death of cell wall

Scientists have done what with genetic engineering?

- engineered bacteria to mass produce a variety os useful chemicals (cancer drugs, pesticides, etc.) - transferred genes from bacteria to plants - transferred genes from one animal species to another

Plant Viruses

- have RNA rather than DNA as genetic material - rod shaped with spiral arrangement of proteins surrounding the nucleic acid

Mutations are often harmful, but can be beneficial

- in nature and laboratory - one source of high diversity of genes in the world, makes natural selection possible

A virus is not usually considered alive because

- it is not cellular - it cannot reproduce on its own

Mutations can involve

- large regions of a chromosome - just a single nucleotide pair (like sickle cell disease)

DNA profiling fingerprinting

- makes use of repeating noncoding DNA segments - people can differ in amount of repeats - can use PCR to increase amount of DNA samples - electrophoresis separates samples by size

Gel electrophoresis

- researchers use this to separate and visualize DNA fragments of different lengths - method used for sorting macromolecules

Mutations can occur by

- spontaneous mutations from random errors during DNA replication or recombination - many other ways

Viruses that infect the plant cells can

- stunt plant growth - diminish crop yields

Polymerase Chain Reaction (PCR)

- technique by which a specific segment of DNA can be amplified: targeted and copied quickly and precisely - permits a scientist to obtain enough DNA from even minute amounts of blood or other tissue to allow a DNA profile to be constructed.

DNA Profiling

- the analysis of DNA samples to determine whether they come from same individual - has rapidly transformed the forensics field

Biotechnology

- the manipulation of organisms or their components to make useful products - dates back to down of civilization (when people used yeast to make bread and beer and selectively bred livestock)

Elongation (3 steps)

1. Codon recognition 2. Peptide bond formation 3. Translocation

Uses for PCR

1. Forensic applications 2. Treatment and diagnosis of disease 3. amplify and detect HIV in blood or tissue samples 4. diagnose hundreds of human genetic disorders by being used with primers that target the genes associated with these disorders

Translation Process (same 3 processes as transcription)

1. Initiation 2. Elongation 3. Termination

3 differences between DNA and RNA

1. Instead of thymine, RNA has a similar base called uracil 2. RNA contains a slightly different sugar than DNA 3.DNA is double stranded

Lytic cycle steps

1. Phage attaches to cell, injects DNA 2. Phage DNA circularizes 3. New phage DNA and proteins are synthesized - Phages assemble 4. Cell lyses, releasing pages

Lysogenic cycle steps

1. Phage attaches to cell, injects DNA 2. Phage DNA circularizes 3. phage DNA is instead into the bacterial chromosome 4. Prophage replicated at each normal cell division - many cell divisions 5. Prophage may leave chromosome

Recombinant DNA is produced by combining two ingredients

1. a bacterial plasmid 2. the gene of interest

Cutting and Pasting DNA steps

1. a restriction enzyme cuts the DNA into fragments 2. A DNA fragment is added from another source 3. Fragments stick together by base pairing 4. DNA ligase joins the fragments into strands

Initiation occurs in 2 steps

1. mRNA molecule binds to a small ribosomal subunit, then a special translator tRNA bings to the start codon (where translation starts) 2. A large ribosomal subunit binds to the small one, creating a functional ribosome

Types of mutations

1. nucleotide substitution 2. nucleotide deletions or insertions

1.pick up appropriate amino acids 2.recognize the appropriate codons in the mRNA

2 distinct functions of tRNA

nitrogenous base, sugar, and phosphate group

3 components of a nucleotide

A mutated DNA sequence is not always a bad situation because it provides __________. A. genetic diversity B. uniformity C. additional codons for translation D. a tightly bound double helix

A

In which of the three phases does translation occur? A. elongation B. initiation Incorrect C. termination D. transcription

A

Of the following examples of "Genetically Modified Plants and Animals", which of the following processes uses biotechnology to insert specific gene sequences from one organism into a completely different organism? A. Transgenic Organisms B. Traditional Breeding C. Mutagenesis D. RNA interference

A

Of the following examples of "Genetically Modified Plants and Animals", which of the following processes uses techniques that selects for desirable traits found in offspring of parents that have been forced to cross pollinate and fertilize each other? A. Traditional Breeding B. Transgenic Organisms C. Mutagenesis D. RNA Interference

A

Recombinant DNA is created when a ___________ cuts the DNA into fragments allowing a DNA fragment from a different source to attach. A. restriction enzyme B. gene splicer C. sticky end D. DNA ligase

A

This field of biotechnology deals with the structure and function of cellular molecules and how they interact to produce traits. This field is an important component to studying the effects of various drugs. A. Proteomics B. Bioinformatics C. Genomics D. Metagenomics

A

When information is transferred from RNA to a polypeptide ___________ occurs. A. translation B. transcription C. DNA synthesis D. RNA mutation

A

Which of the following choices below is the best match for small sequences of DNA repeated many times in tandem, and are commonly used in DNA profiling (DNA fingerprinting) because the chance of two people having 13 of the same of these sequences is almost impossibly rare. A. Short tandem repeats B. Exons C. Codons D. Introns

A

Which type of bond holds together the sugar of one nucleotide and the phosphate of another nucleotide in a repeating pattern? (Hint: this bond must be strong) A. covalent B. ionic C. polar D. hydrogen

A

tRNA (Transfer RNA)

A cell uses a molecular interpreter, a type of RNA called ______, to match amino acids to the appropriate codons to form the new polypeptide.

ribosome

A fully assembled ___________ has 1. a binding site for mRNA on its small subunit and 2. binding sites for tRNA on its large subunit.

amino acid

A given RNA triplet always specifies a given _______ ______

Polynucleotide

A nucleotide polymer which can be very long and may have any sequence of the 4 types of nucleotides (A, C, T, G)

80

A tRNA molecule is made of a single strand of RNA—one polynucleotide chain—consisting of about ____ nucleotides. The chain twists and folds upon itself, forming several double-stranded regions in which short stretches of RNA base-pair with other stretches.

Thymine (DNA) or Uracil (RNA)

Adenine always pairs with _______

hydrogen bonds

As with DNA replication, two DNA strands must first separate at the place where the process will start. In transcription, however, only one of the DNA strands serves as a template for the newly forming RNA molecule; the other strand is UNUSED. The nucleotides that make up the new RNA molecule take their place one at a time along the DNA template strand by forming __________ ______ with the nucleotide bases there.

anticodon

At one end of the tRNA is a special triplet of bases called an ___________ which is complementary to a codon triplet on mRNA

noncoding

Another type of RNA processing is made necessary in eukaryotes by ___________ stretches of nucleotides that interrupt the nucleotides that actually code for amino acids.

mutation

Any change in the nucleotide sequence of a cells DNA is called a __________________

proteins

Because ________, not genes, actually carry out the activities of the cell, scientists must study when and where they are produced and how they interact to understand the functioning of cells and organisms.

What is the manipulation of organisms or their components to make useful products?

Biotechnology

transcribed

Both exons and introns are __________ from DNA to RNA

Pharmaceutical applications

By transferring the gene for a desired protein into a bacterium, yeast, or other kind of cell that is easy to grow in culture, scientists can produce large quantities of useful proteins that are present naturally only in small amounts.

Finish the statement: After replication, ______________________. A. each new DNA double helix consists of two old strands B. each new DNA double helix consists of two new strands C. one new DNA double helix consists of two old strands and the other new DNA double helix consists of two new strands D. each new DNA double helix consists of one old strand and one new strand

C

In human gene therapy ________. A. harmless bacteria make important proteins for humans that cannot produce these proteins on their own B. bacterial plasmids are used to transfer genes to human patients C. normal versions of genes are transferred to patients who carry a mutated allele D. genetically engineered alleles, usually from other species, replace mutated alleles

C

Of the following examples of "Genetically Modified Plants and Animals", which of the following processes causes mutations in plants by exposing seeds to various forms of radiation? A. Transgenic organisms B. Traditional Breeding C. Mutagenesis D. RNA interference (RNAi)

C

Recombinant DNA

Combined pieces of DNA from two different sources, often different species, to form a single DNA molecule

Nucleotides

Consist of long chains (polymers) of chemical units (monomers)

GMO's are beneficial to society in which of the following ways? A. crop resistance B. engineering human proteins C. increasing nutrition in certain foods D. all of the above

D

Of the following examples of "Genetically Modified Plants and Animals", which of the following processes uses enzymes to switch genes off by modifying their expression? A. Transgenic organisms B. Traditional Breeding C. Mutagenesis D. RNA interference (RNAi)

D

The scientific field that studies complete sets of genes is called ________. A. metagenomics B. proteomics C. genetic engineering D. genomics

D

Translation converts the information stored in ________ to ________. A. DNA, RNA B. DNA, a polypeptide C. RNA, DNA D. RNA, a polypeptide

D

Which of the answers below is an example of biotechnology? A. fermentation of beer B. making bread with yeast C. selective breeding of livestock D. all of the above

D

The _____________ enzyme is responsible for permanently bonding DNA fragments.

DNA ligase

To produce a ___________________, scientists compare sequences in the _____________ that vary from person to person

DNA profile, genome

instructions

DNA provides _________ to a cell and the organism as a whole

origins of replication

DNA replication begins on a double helix at specific sites called ________ ___ ____________ then proceeds in both directions creating replication "bubbles"

genetic profiles

Despite problems that can still arise from insufficient data, human error, or flawed evidence, _________ _______ are now accepted as compelling evidence by legal experts and scientists alike.

elongation

During the second phase of transcription, called ___________, the RNA grows longer and the RNA strand peels away from its DNA template, allowing the two separated DNA strands to come back together in the region already transcribed.

Termination

During the third phase of transcription, called ____________, RNA polymerase reaches a special sequence of bases in the DNA template called a terminator, signaling the end of the gene, polymerase detaches from the RNA and the gene, and the DNA strands rejoin.

base-pairing

During translation, the anticodon on the tRNA recognizes a particular codon on the mRNA by using ______-________ rules.

Termination (for translation)

Elongation continues until - a stop codon reaches the ribosomes A site - the completed polypeptide is freed - the ribosome splits back into its subunits

DNA polymerase

Enzyme that make the covalent bonds between the nucleotides of a new DNA strand and can help repair DNA that has been damaged by toxic chemicals or high-energy radiation, such as X-rays and ultraviolet light.

triplet code

Experiments have verified that the flow of information from gene to protein is based on a ________ ______

Mutagenesis

Exposing seeds to atomic radiation (Gamma rays)

True or False: Biotechnology is a relatively new type of technology that is used in modern laboratory techniques.

False

Transgenics

Genes of one organism inserted into another organism.

proteins

Genetic information in DNA is transcribed into RNA, then translated into polypeptides, which then fold into ________

Genes that have been manipulated from one generation to the next, usually artificially, are known as

Genetically modified organisms

Cytosine

Guanine always pairs with ________

Most common physical mutation is...

High energy radiation (X-rays, ultraviolet light)

amplified

In PCR: A DNA molecule within a starting sample is likely to be very long. But, most often, only a very small target region of that large DNA molecule needs to be ________

exponentially growing population of identical DNA molecules

In PCR: 1. A DNA sample is mixed with nucleotides, the DNA replication enzyme DNA polymerase, and a few other ingredients. 2. The solution is then exposed to cycles of heating (to separate the DNA strands) and cooling (to allow double-stranded DNA to re-form). 3. During these cycles, specific regions of each molecule of DNA are replicated, doubling the amount of that DNA. 4. The result of this chain reaction is an __________ _________ ____________ __ ____ _____________

primers

In PCR: The key to amplifying one particular segment of DNA and no others is the use of ________, short (usually 15-20 nucleotides long), chemically synthesized single-stranded DNA molecules. These bind to sequences that flank the target sequence, marking the start and end points for the segment of DNA to be amplified.

13 standard markers

In forensic cases using STR analysis with the __ __________ _________, the probability of two people having identical DNA profiles is somewhere between one chance in 10 billion and one in several trillion.

introns

Most genes of plants and animals include such internal noncoding regions

The common cold, flu, and smallpox are all examples of illnesses that are caused by a virus. Symptoms can range from mild to severe even though the structure of a virus is a relatively simple structure made up of __________ and ___________.

Nucleic acid, protein

Sugar-phosphate backbone

Nucleotides are joined by covalent bonds between the sugar of one nucleotide and the phosphate of the next in a repeating pattern of sugar-phosphate-sugar-phosphate, which is known as a ______-_______ ____________

stop codons

Of the 64 triplets, 3 _____ _______ instruct the ribosomes to end the polypeptide

61

Of the 64 triplets, how many code for amino acids?

cap and tail

One kind of RNA processing is the addition of extra nucleotides to the ends of the RNA transcript. These additions, called the ______ ___ ______, protect the RNA from attack by cellular enzymes and help ribosomes recognize the RNA as mRNA.

Nucleic acids

Organic substance of DNA and RNA

Genetically Modifies Organisms

Organisms that have acquires one or more genes by ARTIFICIAL means

Mutagens

Other sources of mutation that are physical and chemical agents

Human gene therapy

Procedure which is intended to treat disease by introducing genes to the afflicted person --In cases where a single defective gene causes a disorder, the mutant version of a gene may be replaced or supplemented with the normal allele. --This could potentially correct a genetic disorder, perhaps permanently. --In other cases, genes are inserted and expressed only long enough to treat a medical problem.

RNA splicing

Process in which before the RNA leaves the nucleus, the introns are removed and the exons are joined to produce an mRNA molecule with a continuous coding sequence.

DNA replication

Process which ensures that all the body cells in a multicellular organism carry the same genetic information and is also the means by which genetic information is passed along to offspring

RNA polymerase

RNA nucleotides are linked by the transcription enzyme ____ ___________

Genetic engineering

Recombinant DNA technology is widely used in ___________ ___________

Where is translation accomplished? A. Ribosomes B. Lysosomes C. Smooth Endoplasmic reticulum D. Nucleoli

Ribosomes or Smooth ER - ASK TEACHER, he had 2 answers

traditional breeding

Selecting the seeds of plants that have favored traits. Over time those traits become more abundant in a population.

DNA technology

Since ancient times, people have selectively bred agricultural crops to make them more useful. Today, ____ ___________ is quickly replacing traditional breeding programs as scientists work to improve the productivity of agriculturally important plants and animals.

Thymine and Cytosine

Single-ring structures

Viroids

Small and circular RNA molecules that infect plants

prometer

The "start transcribing" signal is a nucleotide sequence called a ________, which is located in the DNA at the beginning of the gene and a specific place where RNA polymerase attaches.

nitrogenous bases

The 4 nucleotides found in DNA differ in their ____________ _______

Restriction site

The DNA sequence recognized by a particular restriction enzyme

Codon recognition (step 1 of elongation)

The anticodon of an incoming tRNA molecule, carrying its amino acid, pairs with the mRNA codon in the A site of the ribosome

exons

The coding regions—the parts of a gene that are expressed

mRNA

The first important ingredient required for translation is the ______ produced by transcription. Once it is present, the machinery used to translate it requires enzymes and sources of chemical energy, such as ATP.

initiation

The first phase of transcription, called _________, is the attachment of RNA polymerase to the promoter and the start of RNA synthesis.

universal

The genetic code is nearly __________, shared by organisms from the simplest bacteria to the most complex plants and animals. --Because diverse organisms share a common genetic code, it is possible to program one species to produce a protein from another species by transplanting DNA. --This allows scientists to mix and match genes from various species—a procedure with many useful genetic engineering applications in agriculture, medicine, and research.

codons

The genetic instructions for the amino acid sequence of a polypeptide chain are written in DNA and RNA as a series of three-base words called ________

Prokaryotes

The majority of organisms sequenced to date are ___________, including over 4,000 bacterial species and nearly 200 archaea.

Bioinformatics

The need to make sense of an ever-increasing flood of information has spawned the field of ___________, the application of computational methods to the storage and analysis of biological data

Proteomics

The successes in genomics have encouraged scientists to begin similar systematic studies of the full protein sets that genomes encode, an approach called __________

Prions

Thought to be a misfolded form of a protein normally present in brain cells

amino acids

Three-base codons in the DNA are transcribed into complementary three-base codons in the RNA. Then the RNA codons are translated into _______ _____ that form a polypeptide.

cloned

Transgenic animals may be _______—nucleus from adult cell introduced into enucleated egg cell produces identical genotype of adult donor

Which term best describes an organism that has received a gene from a different type of organism in order to display a specific trait?

Transgenic organisms

Ribosomes and tRNA

Translation requires 2 other important components:

template

Watson and Crick's model of DNA suggests that each DNA strand serves as a _________ to guide reproduction of the other strand

DNA replication

When a cell reproduces, it must duplicate information, providing one copy to the new offspring cell while keeping one copy for itself.

translation

a conversion between different languages, from the nucleic acid language to the protein language, and involves more elaborate machinery than transcription.

The mRNA has a ______ and _______ that help the mRNA bind to the ribosome

cap, tail

Many mutagens can act as ________________ (agents that cause cancer)

carcinogens

A virus can multiply only by ________________ a living cell and ________________ the cells molecular machinery to make more viruses

infecting, directing

In vivo

inside the body

After a restriction enzyme binds to its restriction site....

it cuts the two strands of the DNA by breaking chemical bonds at specific points within the sequence

Adenine and guanine

larger, double-ring structures

Repetitive DNA

makes up much of the DNA that lies between genes in humans and consists of nucleotide sequences that are present in multiple copies in the genome

Ex vivo

outside the body

Short tandem repeats (STRs)

short sequences of DNA repeated many times, tandemly (one after another), in the genome

RNA interference

technology used to switch genes "on and off", by modifying their expression. Occurs naturally as "editing" tools

Restriction Enzymes

the cutting tools used for making recombinant DNA

Transgenic Organism

the newly acquired gene is from another organism, typically of another species

Gene cloning

the production of multiple identical copies of a gene-carrying piece of DNA

Pharming

use of transgenic farm animal to produce pharmaceuticals in milk

Viruses are giants compared to ___________ and ___________

viroids, prions