Chapter 8, 9,10

An mRNA molecule that is 99 bases long will create a protein composed of

33 amino acids

Sickle-cell disease is an inherited chronic blood disease caused by an autosomal recessive allele. Suppose a man with sickle-cell disease fathers a child by a woman who is a carrier for sickle-cell disease. What are the chances their children will exhibit the disease?

50 percent

Since 1900, at least ________ people worldwide have died as a result of an H1N1 influenza infection.

50,285,000

which of the following codes for proline

CCU

A segment of DNA in a test tube replicates and produces many copies of itself. What was probably in the test tube that enhanced this process?

DNA Polymerase

The enzyme that copies DNA is called

DNA polymerase

Which of the following must occur for a mismatch error to be repaired?

DNA repair proteins identify damaged DNA.

If one strand of DNA has the sequence CGATT, the sequence of the other strand of the same molecule will be

GCTAA.

During cell division a piece of a chromosome breaks off and reattaches to the same chromosome, but the piece is now in reverse order. How would this abnormality affect the chromosome?

Genes in the section that was inverted could lose normal function.

If a father is affected by an X-linked recessive condition and the mother is a carrier, what is the probability of their children being affected?

Half of the sons will be affected

Because an individual with an XX genotype is a female, is an individual with an XO (no second sex chromosome) a male?

No, because the Y chromosome contains the gene that makes an embryo male.

Match the steps of transcription and translation to the location they take place within a eukaryotic cell.

Nucleus- RNa splicing cytoplasm- pairing of codons and anticodons nucleus-construction of an mRNA molecule cytoplasm- formation of a covalent bond between amino acids

Before using the CRISPR-Cas9 system to edit the pig genome, it is necessary to sequence the pig DNA to identify any copies of porcine endogenous retrovirus (PERV) DNA. Knowing the PERV DNA sequences will help researchers determine which ________ sequences to use as guides for the CRISPR-Cas9 complex.

RNA

The key enzyme used during transcription is

RNA polymerase

The CRISPR-Cas9 system is made up of two guide ________ molecules and two Cas9 ________ molecules.

RNA; protein

While examining the pedigree of a human female, you discover that she has 44 autosomes and two sex chromosomes, an X and a Y. This may lead you to suspect that there is a mutation within this individual's ________ gene.

SRY

A mutation occurs in the promoter of a protein-encoding gene. How might this mutation affect the production of the protein encoded by the gene?

The promoter might not be recognized by RNA polymerase, so the enzyme would be unable to attach to the promoter and start transcription.

When studying genomes of organisms, scientists often will only list the sequence of a single strand. Explain why the sequence of the second strand would be unnecessary information.

The sequence of the second strand is complementary to the first strand and would not provide any additional information. It is a simple thing to determine the sequence based on base-pairing rules.

Using the figure below, describe how the two guide RNA molecules in the CRISPR-Cas9 system find the target DNA sequence.

The two guide RNA molecules find the segments of the DNA with their complementary base sequence and link with it. These DNA segments of bases are "clustered regularly interspaced short palindromic repeats" (CRISPR).

In which of the following situations would looking at a pedigree be MOST useful?

Three young boys who are first cousins show symptoms of a neurological disorder

Which of the following codons codes for the same amino acid as the codon AGU?

UCA

A scientist adds a single polymerase and primer to a polymerase chain reaction (PCR) but does not add nucleotides. How many strands would be present after three replications if a single original strand was present? Explain your answer.

Without nucleotides, PCR cannot proceed. Therefore, only the single original strand would be present after three rounds.

The first human trial using CRISPR and approved by NIH used the system to edit

a cancer patient's own immune system cells.

During transcription

a template strand of DNA directs the production of an mRNA molecule.

In a single strand of DNA, the total number of phosphate groups present is equal to the total number of ________ bases.

adenine, thymine, guanine, and cytosine

Put the following in order from smallest to largest:

base, nucleotide, base pair, gene, genome

The order of the bases in DNA determines the order of the

bases in mRNA.

In humans the tRNA with the anticodon AAU carries the amino acid leucine. In plants, this tRNA would

carry the same amino acid.

When a cell divides, it

copies its own genetic information

A disease caused by an inherited mutation is a ________ disorder.

genetic

Short lengths of DNA are wound around bundles of ________ to create a structure consisting of many nucleosomes strung together by strings of DNA.

histone proteins

The two strands of a DNA molecule are held together by ________ bonds between their base pairs.

hydrogen

Replication of DNA cannot begin until ________ bonds between ________ are broken.

hydrogen; complementary bases

Phenylketonuria (PKU) is a metabolism disorder that can result in mental retardation if untreated. This recessive disorder is caused by a defective gene located on chromosome twelve. The most reliable source for the functional gene needed for gene therapy would be a(n)

individual that is homozygous dominant for the functional gene.

It could help meet transplant needs to use a patient's own stem cells to grow a human liver in a pig embryo modified by CRISPR. As an additional and essential step in the process to ensure the liver is safe for the patient, CRISPR should be used to

knock out all of the porcine endogenous retrovirus (PERV) genes to prevent infection of the human patient with porcine endogenous retroviruses.

Every gene in a human occupies a specific position or ________ on a chromosome.

locus

Protein-coding genes specify the production of ________ as their immediate product.

mRNA

During translation,

one mRNA molecule works with several rRNA molecules and many tRNA molecules to produce a protein.

A ________ is a chart that shows genetic relationships within a family over several generations.

pedigree

The polymerase chain reaction (PCR) is used to

produce many copies of a selected DNA sequence.

A protein that binds to the ________ of DNA down-regulates protein production by inhibiting the binding of RNA polymerase.

promotor

An allele that is not expressed in heterozygous carriers is called a(n) ________ allele.

recessive

The genetic disorder followed through the pedigree shown below is

recessive and autosomal.

Exposure to ultraviolet (UV) light can alter DNA sequences in a cell. Uncorrected, these changes can lead to skin cancer. Individuals who have a mutation in a gene that produces DNA ________ protein may be at an increased risk for skin cancer.

repair

DNA fingerprinting is based on regions of DNA that are variable between individuals. Many of these differences between individuals produce no change in phenotype. This type of mutation is a(n)

silent mutation

Which RNA molecule brings new amino acids to the growing protein chain in translation

tRNA

A researcher finds a molecule that is made of nucleotides and has a single amino acid bound to one end. This molecule is most likely a ________ molecule.

tRNA transfer RNA

In humans, X-linked genetic diseases

tend to be expressed more in males than in females

The difference between the alleles of a single gene is

their DNA base sequences.

In the genetic code, a codon is ________ bases long for ________.

three; all cell types

A gene in a region of DNA that is wound more tightly around proteins in the nucleus will be

transcribed less often than other genes.

Prokaryotes lack membrane-enclosed organelles and thus do not have nuclei. Therefore, prokaryotic

transcription and translation both take place in the cytoplasm.

On chromosomes within an individual, there are ________ alleles for a given gene found on ________ chromosomes

two; homologous

The sequence of DNA differs among individuals within a species. This is the reason for

variations in phenotypes.