05:12Introduction to nucleic acids and nucleotides | High school biology | Khan AcademyKhan Academy965views2rank
Multiple ChoiceWhich of the following descriptions best fits the class of molecules known as nucleotides?3270views28rank
Multiple ChoiceWhich of the following is true regarding complementary base pairing in DNA and RNA molecules? 1626views1rank
Multiple ChoiceWhich of the following lists represents the chemical components of a nucleotide? 2593views
Multiple ChoiceBased on complementary base pairing, you would expect the percentage of __________ to be equal to the percentage of __________. 1026views
Multiple ChoiceA shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture __________. 826views
Textbook QuestionWhat are the four nitrogenous bases found in RNA? a. cytosine, guanine, thymine, uracil (C, G, T, U) b. adenine, cytosine, guanine, thymine (A, C, G, T) c. adenine, cytosine, guanine, uracil (A, C, G, U) d. alanine, cysteine, glycine, threonine (A, C, G, T)792views
Textbook QuestionWhat determines the primary structure of a DNA molecule? a. stem-and-loop configuration b. complementary base pairing c. deoxyribonucleotide sequence d. hydrophobic interactions and hydrogen bonding911views
Textbook QuestionEvaluate the following statements related to the synthesis of nucleic acids. Select True or False for each statement. T/F Ribonucleotides are added to the 3′ end of a DNA strand. T/F Polymerization of nucleic acids occurs by the formation of phosphodiester bonds. T/F Complementary pairing between sugars is required for copying nucleic acids. T/F Strands in a double helix are synthesized in an antiparallel orientation.820views
Textbook QuestionSingle strands of nucleic acids are directional, meaning that there are two different ends. What functional groups define the two different ends of a strand?1404views
Textbook QuestionEnzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? a. The two strands of the double helix would separate. b. The phosphodiester linkages of the polynucleotide backbone would be broken. c. The pyrimidines would be separated from the deoxyribose sugars. d. All bases would be separated from the deoxyribose sugars.2171views
Textbook QuestionIf nucleotides from the DNA of a human were quantified and 30 percent of them contained the base adenine, what percentage of them would contain the base guanine? a. 20 percent b. 30 percent c. 40 percent d. 70 percent759views
Textbook QuestionWhich of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? a. 5′-AGCT-3′ with 5′-TCGA-3′ b. 5′-GCGC-3′ with 5′-TATA-3′ c. 5′-ATGC-3′ with 5′-GCAT-3′ d. All of these pairs are correct.2268views
Textbook QuestionA shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture a. DNA. b. proteins. c. cellulose. d. sucrose.1614views
Textbook QuestionWhat would be the sequence of the strand of DNA that is made from the following template: 5′-GATATCGAT-3′? (Your answer must be written 5'→3'.) How would the sequence be different if RNA were made from this DNA template?798views
Textbook QuestionAccording to the RNA world model, a ribozyme would replicate by creating a double-stranded RNA intermediate. Would you expect the intermediate to have the same catalytic activity as the original ribozyme? Justify your answer with an explanation.755views
Textbook QuestionMake a concept map (see BioSkills 12) that relates DNA's primary structure to its secondary structure. Your diagram should include deoxyribonucleotides, base-stacking interactions, purines, pyrimidines, phosphodiester linkages, DNA's primary structure, DNA's secondary structure, complementary base pairing, and antiparallel double helix.650views
Textbook QuestionRNA and DNA are similar because . a. both are double-stranded helices; b. uracil is found in both of them; c. both contain the sugar deoxyribose; d. both are made up of nucleotides consisting of a sugar, a phosphate, and a base1479views
Textbook QuestionDRAW IT Copy the polynucleotide strand in Figure 5.23a and label the bases G, T, C, and T, starting from the 5′ end. Assuming this is a DNA polynucleotide, now draw the complementary strand, using the same symbols for phosphates (circles), sugars (pentagons), and bases. Label the bases. Draw arrows showing the 5'→3' direction of each strand. Use the arrows to make sure the second strand is antiparallel to the first. Hint: After you draw the first strand vertically, turn the paper upside down; it is easier to draw the second strand from the 5′ toward the 3′ direction as you go from top to bottom.777views
Textbook QuestionIn the field of nanotechnology, DNA is used like Velcro to assemble tiny particles into structures that are < 0.0001 mm in size. Draw a model to illustrate how two particles (a circle and a square) could be brought together by linking them to short single-stranded DNA molecules. If the DNA sequence linked to the circle is GGATC, then provide the sequence linked to the square and identify the 5′ and 3′ ends of each strand.888views
Textbook QuestionExplain the role of complementary base pairing in the functions of nucleic acids.800views
Textbook QuestionWhich of the following is not part of a nucleotide?a. An amino acidb. A nitrogenous basec. One or more phosphate groupsd. A sugar204views
Textbook QuestionMark the following properties as belonging to either DNA or RNA.a. Contains the nucleotides A, G, C, and U ____ b. Found only in the nucleus of the cell ____ c. Can move in and out of the cell's nucleus ____ d. Contains two strands of nucleotides linked by hydrogen bonds____ e. Contains the code for every protein in the body____ f. Contains the sugar ribose____ 204views
Textbook QuestionThe drug methotrexate is used to treat several different types of cancer and diseases of the immune system. It works by inhibiting an enzyme in the cell necessary for folic acid synthesis. Without folic acid, the cell cannot make nucleotides. What, specifically, does an enzyme do in the cell? Why would inhibiting this enzyme disrupt folic acid synthesis? What effect would a disruption in folic acid synthesis have on the cell as a whole? (Hint: Think about the role that folic acid plays in the cell.) (Connects to Chapter 2)194views