Genetics BIO

A single mutation causes sickle-cell disease. Which of the following statements best describes how this occurs?

A single nucleotide mutation causes a normal glutamine amino acid to be replaced with a valine amino acid. This causes the resulting hemoglobin protein to form incorrectly, resulting in sickle-shaped red blood cells that cannot function as intended.

Which of the following best describes the sequence of DNA compaction, beginning with least compacted to most compacted?

DNA strand, nucleosomes, chromosomes

Which of the following is the main difference between in vivo and ex vivo gene therapy?

Ex vivo gene therapy occurs outside the body and in vivo gene therapy occurs inside the body.

Which of the following statements best describes the structure of a hemoglobin molecule?

Hemoglobin is comprised of four globin molecules, each with their own heme group that binds to and carries oxygen.

Which of the following best describes the overall goal of transcription?

To create a mRNA copy of a segment of DNA to take outside the nucleus.

Sickle-cell disease is a disorder that is caused by...

a single mutation on a single gene.

Images of unreplicated chromosomes that allow researchers to organize and identify each chromosome, as well as missing or extra chromosomes is called a(n) _____.

karyotype

Sickle-cell disease results in malformed hemoglobin molecules. Which cell type contains millions of hemoglobin molecules per cell?

red blood cells

A method of genome editing that uses the Cas9 enzyme to identify and cut specific nucleotides from the genome is called _____.

CRISPR (clustered regularly interspaced short palindromic repeats)

True or False: Gene therapy has been used for years to treat or cure sickle-cell disease.

False

True or False: Sickle-cell disease is a recessive disease. This means that two individuals without the disease cannot have a child with the disease. Only parents with the disease can pass it on.

False

If the codon is CCA, what is the anticodon and what amino acid will be inserted?

GGU, proline

DNA microarrays use enzymes to convert mRNA obtained from the cell into cDNA. This cDNA is hybridized with known DNA from specific genes isolated from the organism. If hybridization occurs, what does this mean?

It means the cDNA has bound to complementary DNA on the microarray, indicating that the corresponding gene is being expressed in the cell.

Sickle-cell disease results in misshapen red blood cells. What impact does this have on their ability to carry gases in the bloodstream.

It reduces their ability to carry oxygen, resulting in anemia.

What is the role of the enzyme ligase in DNA replication?

It seals any breaks in the sugar-phosphate backbone.

Which of the following statements about PCR is true?

PCR uses DNA polymerase

Two parents with Type A and Type B blood have a child with Type AB blood. How is this possible?

Type A blood is codominant with Type B blood, so both alleles are expressed equally.

During gene therapy, bone marrow stem cells are removed from the individual. What must happen to those cells before they are injected back into the individual?

Viruses act as vectors to carry the normal gene into the genome of the stem cells

DNA replication is considered to be _____ because the end product consists of one old strand and one newly synthesized strand.

semiconservative

Erwin Chargaff's research determined the composition of the nitrogen bases within a strand of DNA. His work determined that

the percent of adenine is equal to the percent of thymine and the percent of cytosine is equal to the percent of guanine.

What is the name of the enzyme that fits new complementary DNA nucleotides into the new strand?

DNA polymerase

Sickle-cell disease causes hemoglobin proteins to become altered. What direct effect does this have on red blood cells?

Red blood cells become sickle-shaped, clumping up and blocking blood flow in capillaries.

Which of the following most accurately describes how sickle-cell disease impacts the body?

Red blood cells clump up, blocking capillaries within the alveoli, resulting in acute chest syndrome, marked by pain, fever, and shortness of breath.

During the human life cycle, the fertilization of an egg by a sperm results in

a diploid zygote

Where within the lungs does gas exchange occur?

alveoli

During prophase I of meiosis, genetic information is exchanged between two homologous chromosomes, resulting in new combinations of alleles. This process is called _____.

crossing-over

Segments of DNA that contain instructions for making either proteins or RNA molecules that regulate proteins are called _____.

genes

A variation in the pattern of nucleotides that often contributes to genetic anomalies is called a(n) _____.

genetic marker

Select all of the following that are components of DNA.

-a deoxyribose sugar -a phosphate group -ribose sugar -two carbohydrate rings with hydroxide groups attached

Select all of the following statements that describe the structure of a molecule of DNA.

-twisted double helix -single-stranded -contains the nitrogenous bases, adenine, thymine, cytosine, and guanine -contains deoxyribose sugar

The pedigree shown displays the occurrence of an inherited disease. For an individual in the fourth generation with two heterozygous parents, what is the likelihood that they will be impacted by the disease?

25%

Which of the following is not an accurate statement describing the contributions of researchers to the structure of DNA.

Alfred Hershey and Martha Chase injected viruses into mice to determine that the inheritable material was DNA and not protein.

Which of the following statements accurately describes the impacts of sickle-cell disease on the body.

Anemia prevents the immune and lymphatic systems from working properly, resulting in decreased immunity.

Which of the following traits are considered to be inheritable?

Eye color

Which of the following is the most effective means of treating or even curing sickle-cell disease?

Gene therapy

Sickle-cell disease is a disorder that results in malformed hemoglobin molecules. What is the result of this in terms of hemoglobin function?

Hemoglobin has a reduced ability to bind to and transport oxygen in red blood cells.

Describe the movement of oxygen and carbon dioxide during gas exchange.

Oxygen diffuses out of the lungs into red blood cells and carbon dioxide diffuses out of red blood cells and into the lungs.

RNA polymerase has several jobs during the transcription process. Which of the following is not a job that it performs?

RNA polymerase edits the mRNA strand by removing some sections and splicing together remaining sections.

Several different researchers all contributed to the study of the structure of DNA. For each of the following researchers, match their contribution.

Rosalind Franklin- DNA is a repeating helical structure. Frederick Griffith - There is a transforming factor that exists and can change bacteria's characteristics. Oswald Avery - Transformation of bacteria did not occur with the addition of Dnase enzyme, suggesting DNA is the genetic material. Erwin Chargaff - The percent of adenine is equal to the percent of thymine and the percent of guanine is equal to the percent of cytosine.

Duplicated chromosomes result in two sister chromatids that are held together by a centromere. Which of the following statements best describes the location of genes along these sister chromatids?

Sister chromatids have identical alleles that are located in the same place along each sister chromatid.

Which of the following best describes how the environment may play a role in the expression of our genes.

Some phenotypes, including skin color, can be influenced by the environment. The genotype still determines some aspect of skin color, but the interaction with the environment, in the form of sun exposure, can cause variations in the resulting phenotype.

Humans have two sex chromosomes that are named based on their shape. Males have (a) _____ and females have (a) _____.

X and Y chromosome; two X chromosomes

For the following pedigree, what does the green circle in the fourth generation represent?

female with the disease

Some traits are multiple-allele traits, meaning there are more than simply one recessive and one dominant allele possible. Which of the following is not an example of a multiple-allele trait?

sickle-cell disease

In humans, male gametes are called _____, while female gametes are called _____.

sperm; eggs

Familial hypercholesterolemia is a disease that is incompletely dominant. This means that

the dominant allele does not fully mask the recessive allele, so an intermediate phenotype is displayed. In the case of familial hypercholesterolemia, heterozygotes have moderately higher levels of cholesterol compared to normal.

Mendel crossed pea plants dominant for two different traits (tall and green pods) with pea plants recessive for those same two traits (short and yellow pods). This cross resulted in pea plants that had combinations of all four traits (tall with green pods, tall with yellow pods, short with green pods, and short with yellow pods). Which law of inheritance best describes why this happens?

the law of independent assortment

Sickle-cell disease is a recessive genetic disease. This means

two copies of the recessive allele must be present in order for the disease to be expressed.