2. Cell Chemistry & Cell Components

If 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 percentb. 30 percentc. 40 percentd. 70 percent

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture __________.

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacturea. DNA.b. proteins.c. cellulose.d. sucrose.

A glucose molecule is to starch as __________.

What 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?

DRAW 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.

Explain the role of complementary base pairing in the functions of nucleic acids.

What is responsible for the increased stability of DNA compared to RNA?

Which 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.

Enzymes 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.

What 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)