Chapter 6

What distinguishes an embryonic stem cell from a somatic cell of an adult organism?

Embryonic stem cells can produce more of themselves as well as produce specialized cells, but somatic cells are already specialized.

The larger an organism is, the larger its genome must be.

False

The process by which genetic information in DNA is copied into RNA is called translation.

False

During translation, one mRNA can be translated by many ribosomes at once.

True

Forensic DNA typing can prove the innocence of a crime suspect.

True

Mutations in regulatory DNA sequences may be more important to evolution than mutations in genes.

True

The process of translation is completed when:

a stop codon moves into the A site.

What is a codon?

a three-base sequence of mRNA that codes for a specific amino acid

Restriction enzymes are mainly derived from:

bacteria.

Introns in genes are:

base sequences not required to make the protein.

Embryonic stem cells are taken from:

blastocysts.

A primary transcript must be edited before becoming this.

mRNA

If a restriction enzyme leaves a sticky end on a DNA fragment, it means the fragment:

has a protruding end of a small number of unpaired bases.

What are the products of translation?

polypeptide chains/proteins

Which is an example of clones that already are produced by nature?

identical twins

By inserting four developmental genes into ordinary cells such as skin cells, Shinya Yamanaka and James Thomson were able to convert them into:

induced pluripotent stem cells.

Which of the following is considered "non-coding" DNA?

introns

Which segment of an mRNA transcript is removed before it is translated?

introns.

In PCR, heating of the DNA is necessary because:

it separates the two strands of DNA.

Approximately what percent of the human genome codes for protein?

less than 2 percent

What roles do plasmids play in biotechnology?

Plasmids are used as a vector to transfer genes between organisms.

Which statement is a characteristic of plasmids?

They can be used to create recombinant DNA.

What is the function of restriction enzymes in bacteria?

They cut foreign DNA, for example, the DNA of invading viruses.

Which of the following statements is true about micro-RNAs?

They regulate the amount of protein in a cell by interfering with mRNAs.

In order for a gene to be transcribed, a multipart protein complex must bind to the ________ to help RNA polymerase align with it.

promoter

DNA fragments cut by most restriction enzymes have:

protruding sticky ends.

This forms part of the structure of a ribosome.

rRNA

When an mRNA moves into the cell's cytoplasm, it first becomes associated with a:

ribosome.

To identify an individual through DNA analysis of his or her blood at crime scenes, investigators look for patterns based on:

short tandem repeats in the DNA.

One end of this links to an amino acid.

tRNA

Which component of transcription or translation has the anticodon?

tRNA

"Bacterial transformation" is a bacterium's ability to:

take up DNA from its surroundings.

Much of the food crops in the United States are transgenic. This primarily has been done to give the crops what properties?

the ability to resist insects and herbicides

tRNAs will move from the A site to the P site to the E site during protein synthesis. These sites are found in:

the large ribosomal subunit.

Kary Mullis was awarded the Nobel Prize in chemistry for inventing:

the polymerase chain reaction.

Hoxc8 genes are responsible for the development of:

thoracic structures in vertebrates.

How many bases does it take to code for a single amino acid?

three

How many codons can act as termination codons?

three

In producing Dolly, the first cloned sheep, how many different sheep were involved, either contributing cells or acting as a surrogate mother?

three

How many different types of amino acids are found in proteins?

20

If a codon is three nucleotides and there are four different nucleotides, how many different codons can be made?

64

In the sequence of events during translation, what is the next step after an mRNA binds to the ribosome's small subunit?

A tRNA binds to the start codon, and the large ribosomal subunit joins the ribosome.

If a DNA segment has the sequence GCTAA, what RNA sequence will be made from it?

CGAUU

This contains large segments that used to be considered "junk."

DNA

In reproductive cloning, a sperm is not used, but an egg is still required. Why?

Egg proteins are required for embryonic development.

Which of the following need to be included in a PCR reaction?

DNA, nucleotides, DNA polymerase, primers

On what basis does forensic biotechnology distinguish one individual from another?

Different people will have a different number of tandem repeats at the same location in their genomes.

What is the advantage of implanting iPS cells derived from the patient's own body rather than ESCs?

ESCs could be rejected by the patient's body because they are seen as foreign.

If a codon has the sequence CAG, tRNA with which anticodon will bind to it?

GUC

The human genome codes for 20,000 to 25,000 proteins, but any given cell might produce only 5,000 different proteins. How is this possible?

Genes are regulated so that not all genes are transcribed in all cells.

Why is PCR useful?

It allows for making many copies of DNA when the starting sample is small.

Why is forensic DNA analysis an important part of biotechnology?

It is used to match two samples of DNA.

The restriction enzyme EcoRI cuts between the G and the A of the sequence GAATTC. Which statement is true about this enzyme?

It leaves sticky ends of sequence AATT.

In reproductive cloning, cells are subjected to an electric current under special circumstances. What effect does this have?

It mimics fertilization and begins embryonic development.

What does the RNA polymerase enzyme complex do?

It unwinds the DNA, brings complementary RNA nucleotides to DNA, and synthesizes an RNA molecule.

You are a crime scene investigator, and the only evidence you are able to gather at the crime scene are some strands of hair. You want to see whether a suspect in custody was at the crime scene. What technique would you use to try and connect the suspect to the crime scene?

PCR followed by analyzing small tandem repeats

Which molecule is the product of transcription?

RNA

The enzyme responsible for transcribing DNA is:

RNA polymerase.

What accounts for the fact that cells in different tissues and organisms have different functions and respond differently to their environments?

The cells are expressing (using) different genes.

In the sequence of events during translation, what is the next step after an amino acid on the tRNA in the P site is linked to an amino acid on the tRNA in the A site?

The ribosome shifts down the mRNA by one codon.

If you compared two samples of DNA at three different locations in the genome and found they had different lengths of short tandem repeats at each location, what could you conclude?

The two samples came from different individuals.

If you found the same number of short tandem repeats at three different locations in two samples of DNA, what would you conclude?

The two samples were most likely from the same individual.

What is a "cloning vector"?

a DNA vehicle that carries recombinant DNA into cells

Which of the following is the best description of a gene?

a segment of DNA that is transcribed into an mRNA, a tRNA, or an rRNA

Translation of mRNA into protein always starts at:

an AUG codon.

"Dolly" or another reproductively cloned animal is a clone of:

an adult animal that contributed DNA to an enucleated egg.

The set of nucleotides on a tRNA that base-pairs with nucleotides on an mRNA is the:

anticodon.

Pigs rich in omega-3 fatty acids:

are examples of transgenic animals.

A three-nucleotide sequence on an mRNA that codes for an amino acid is referred to as a/an:

codon.

"Golden rice" is a transgenic form of rice because it:

contains genes from a bacterium and a daffodil.

Dietary factors are now being studied for how they regulate gene activity and how this contributes to disease. For example, how does a diet high in unsaturated fatty acids help maintain a healthy blood lipid profile? Within hours of feeding animals with diets rich in polyunsaturated fatty acids (PUFAs), there is an increase in the activity of genes responsible for making enzymes that break down fats and a reduction of the activity of genes responsible for making enzymes that make fats. This has the effect of changing fat metabolism, which leads to a lowering of blood lipid levels. The control of what type of DNA sequence would PUFAs most likely be affecting?

enhancer sequences

Genetically modified crops have been produced mainly to benefit:

farmers.

These regulatory sequences reduce production of specific proteins.

micro-RNA

Dolly, the cloned sheep, is the product of which technique?

reproductive cloning

What is used to cut DNA in generating recombinant DNA?

restriction enzymes

The genetic code:

shows the connection between nucleotide triplets and the amino acids they code for.

Stem cells are said to be pluripotent. This means they have the ability to:

specialize into any other type of cell.

Cells that can give rise to more of its kind along with at least one variety of specialized cell are known as:

stem cells.

Which of the following brings amino acids to the ribosomes?

transfer RNA

Tobacco plants have had a gene from fireflies inserted into them which makes them glow. These tobacco plants would be considered:

transgenic organisms.

Which of the following is a component of an RNA nucleotide?

uracil

Biotechnology can be defined as the:

use of technology to control biological processes as a means of meeting societal needs.