Principles Of Biology 1 (Unit 3 Study Guide)
20.Several different researchers all contributed to the study of the structure of DNA. For each of the following researchers, match their contribution.
Answer: Rosalind Franklin: DNA is a repeating helical structure. 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. Frederick Griffith: There is a transforming factor that exists and can change bacteria's characteristics. Oswald Avery: Transformation of bacteria.
27.Select all of the following that are components of DNA.
Answer: A deoxyribose sugar, A phosphate group, The nitrogenous bases, thymine, adenine, cytosine, and guanine.
11.During the human life cycle, the fertilization of an egg by a sperm results in.
Answer: A diploid zygote.
16.Sickle-cell disease is a disorder that is caused by...
Answer: A single mutation on a single gene.
5. A single mutation causes sickle-cell disease. Which of the following statements best describes how this occurs?
Answer: 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.
19.CRISPR was discovered.
Answer: Accidentally, by scientists working with bacteria in the food industry. They were looking for ways to make cheese and yogurt production more effective.
13.Variations in genes are called _____. Examples of these variations include eye color. There are blue eyes, green eyes, brown eyes, and several combinations of these.
Answer: Alleles.
24.A method of genome editing that uses the Cas9 enzyme to identify and cut specific nucleotides from the genome is called _____.
Answer: CRISPR (clustered regularly interspaced short palindromic repeats).
30.Susie is pregnant with her first child. Because of her advanced maternal age and a family history of various genetic disorders, her doctor has recommended genetic testing to ensure her offspring is healthy. Her doctor places a long thin suction tube through her vagina into the uterus, where it obtains fetal cells from the chorion of the developing embryo. These cells are then sent off for testing. What is this type of procedure called?
Answer: Chorionic villus sampling (CVS).
17.During metaphase I of meiosis, genetic information is exchanged between two homologous chromosomes, resulting in new combinations of alleles. This process is called _____.
Answer: Crossing-over.
3. What is the name of the enzyme that fits new complementary DNA nucleotides into the new strand?
Answer: DNA polymerase.
7. Which of the following traits are considered to be inheritable?
Answer: Eye color.
1. Which of the following is the most effective means of treating or even curing sickle-cell disease?
Answer: Gene therapy.
23.Segments of DNA that contain instructions for making either proteins or RNA molecules that regulate proteins are called _____.
Answer: Genes.
9. Which of the following best describes the definition of a gene?
Answer: Genetic information that produces a product, either proteins or RNA.
26.Sickle-cell disease results in misshapen red blood cells. What impact does this have on their ability to carry gases in the bloodstream.
Answer: It reduces their ability to carry oxygen, resulting in anemia.
31.What is the role of the enzyme ligase in DNA replication?
Answer: It seals any breaks in the sugar-phosphate backbone.
15.Mendel's experiments led him to the conclusion that individuals have two factors for each trait that separate during gamete formation, resulting in gametes with one factor for each trait. In addition, fertilization results in a new individual with two factors for each trait again. He referred to this as the _____.
Answer: Law of segregation.
10.Complete the following sentence: Hemoglobin functions in _____ cells and carries ____ to all cells of the body.
Answer: Red Blood, Oxygen.
6. Sickle-cell disease causes hemoglobin proteins to become altered. What direct effect does this have on red blood cells?
Answer: Red blood cells become sickle-shaped, clumping up and blocking blood flow in capillaries.
14.Which of the following most accurately describes how sickle-cell disease impacts the body?
Answer: Red blood cells clump up, blocking capillaries within the alveoli, resulting in acute chest syndrome, marked by pain, fever, and shortness of breath.
29.Sickle-cell disease results in malformed hemoglobin molecules. Which cell type contains millions of hemoglobin molecules per cell?
Answer: Red blood cells.
28.Meiosis is different from mitosis in that meiosis.
Answer: Results in four haploid daughter cells that are genetically diverse, whereas mitosis results in two diploid daughter cells that are genetically identical.
18.In humans, male gametes are called _____, while female gametes are called _____.
Answer: Sperm, Eggs.
21.Meiosis proceeds different in males compared to females. Which of the following best describes one of those differences?
Answer: Spermatogenesis results in the production of four haploid sperm cells and oogenesis results in the production of a single haploid egg cell.
25.CRISPR may work to treat sickle-cell disease by.
Answer: Targeting faulty portions of the hemoglobin gene within the genome of cells and removing and replacing those portions with normal sequences of nucleotides.
8. Sickle-cell disease is a recessive genetic disease. This means.
Answer: Two copies of the recessive allele must be present in order for the disease to be expressed.
2. 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?
Answer: Viruses act as vectors to carry the normal gene into the genome of the stem cells.
12.Humans have two sex chromosomes that are named based on their shape. Males have (a) _____ and females have (a) _____.
Answer: X and Y chromosome, two X chromosomes.
4. Images of unreplicated chromosomes that allow researchers to organize and identify each chromosome, as well as missing or extra chromosomes is called a(n) _______.
Answer: karyotype.
22.During translation, a polypeptide chain is created using a RNA template. Which of the following components is responsible for bringing amino acids to the growing polypeptide chain?
Answer: tRNA.
