AP Bio 5.5 and 5.6 hw

If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain? a) 25 b) 50 c) 200 d) 75 e) 150

d) 75 100 nucleotide pairs are a total of 200 nucleotides. Because of base pairing, if there are 25 adenine there must also be 25 thymine. This leaves 200-50 = 150 nucleotides to be divided evenly between guanine and cytosine.

Which statement helps to explain how DNA stores hereditary information? a) DNA is a self-replicating type of protein. b) DNA contains 20 kinds of amino acids. c) DNA is made from thousands of kinds of monomers. d) DNA contains four kinds of nitrogenous bases. e) DNA binds a master copy of each kind of protein.

d) DNA contains four kinds of nitrogenous bases. Correct! Information is stored in the sequence of nitrogenous bases along the DNA polymer. The bases include two kinds of pyrimidines and two kinds of purines.

One of the primary functions of RNA molecules is to _____. a) transmit genetic information to offspring b) make a copy of itself, thus ensuring genetic continuity c) act as a pattern or blueprint to form DNA d) function in the synthesis of proteins

d) function in the synthesis of proteins

DNA and mRNA differ with respect to ... - Both (a) and (b). - (b) the kinds of purines they contain. - (d) the ability to make a double helix. - (c) how many kinds of nucleotides are used to make the polymer. - (a) the kind of sugar they contain.

(a) the kind of sugar they contain. Right! RNA uses ribose; DNA uses deoxyribose. The polymer names reflect this difference: RNA is short for Ribonucleic acid; DNA is short for deoxyribonucleic acid.

Which statement is true of nucleic acids? (a) rRNA positions amino acids along mRNA. (b) mRNA binds amino acids together to make proteins. (c) mRNA is part of the ribosome. (d) DNA carries information for making RNA. e) Both (b) and (d).

(d) DNA carries information for making RNA. Correct! All RNA is made by copying segments of DNA.

_______ have two linked rings.

Purines

The flow of genetic information in a cell goes from _____. a) DNA to RNA to protein b) DNA to lipid to protein c) DNA to ribosomes to RNA d) protein to RNA to DNA e) DNA to RNA to glucose

The information in DNA is transcribed into RNA and then translated into protein.

(*Refer to the molecule chart thing) Which of the following molecules is a purine nitrogenous base? a) 13 b) 5 c) 2 d) 12

a) 13

If a DNA sample were composed of 10% thymine, what would be the percentage of guanine? a) 40 b) 80 c) 10 d) It is impossible to tell from the information given.

a) 40

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence _____. a) 5'TGCAAT3' b) 5'TAACGT3' c) 3'UAACGU5' d) 5'UGCAAU3'

a) 5'TGCAAT3'

If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled? a) RNA b) both DNA and RNA c) DNA d) proteins

a) RNA

Nucleic acids are polymers made up of which of the following monomers? a) nucleotides b) amino acids c) sugars d) nitrogenous bases

a) nucleotides

If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand? a) 3'-UAAACG-5' b) 3'-TAAACG-5' c) 3'-GCAAAT-5' d) 3'-TUUUCG-5' e) 3'-ATTTGC-5'

b) 3'-TAAACG-5' Adenine pairs with thymine and guanine pairs with cytosine.

When nucleotides polymerize to form a nucleic acid _____. a) a hydrogen bond forms between the sugar of one nucleotide and the phosphate of a second b) a covalent bond forms between the sugar of one nucleotide and the phosphate of a second c) hydrogen bonds form between the bases of two nucleotides d) covalent bonds form between the bases of two nucleotides

b) a covalent bond forms between the sugar of one nucleotide and the phosphate of a second

Which of the following includes all of the pyrimidines found in RNA and DNA? a) cytosine and thymine b) cytosine, uracil, and thymine c) cytosine and uracil d) cytosine, uracil, and guanine

b) cytosine, uracil, and thymine

The building blocks or monomers of nucleic acid molecules are called _____. a) pyrimidines and purines b) nucleotides c) DNA and RNA d) polysaccharides e) fatty acids

b) nucleotides A nucleotide is a nucleic acid monomer consisting of a nitrogen base, a pentose sugar, and a phosphate group. Nucleotides joined together by covalent bonds called phosphodiester linkages form nucleic acid molecules.

Which of the following statements about the 5' end of a polynucleotide strand of RNA is correct? a) The 5' end has a hydroxyl group attached to the number 5 carbon of ribose. b) The 5' end has a carboxyl group attached to the number 5 carbon of ribose. c) The 5' end has a phosphate group attached to the number 5 carbon of ribose. d) The 5' end has phosphate attached to the number 5 carbon of the nitrogenous base.

c) The 5' end has a phosphate group attached to the number 5 carbon of ribose.

A nucleotide is composed of a(n) _____. a) phosphate group, a nitrogen-containing base, and a hydrocarbon b) glycerol, a nitrogen-containing base, and a five-carbon sugar c) phosphate group, a nitrogen-containing base, and a five-carbon sugar d) amino group, a nitrogen-containing base, and a five-carbon sugar e) sulfhydryl group, a nitrogen-containing base, and a five-carbon sugar

c) phosphate group, a nitrogen-containing base, and a five-carbon sugar These are the components of a nucleotide.

A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism is more closely related to _____. a) rats than to frogs b) humans than to frogs c) gibbons than to rats d) frogs than to humans

d) frogs than to humans

The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases. a) ionic bonds b) covalent bonds c) hydrophilic interactions d) hydrogen bonds e) S—S bonds

d) hydrogen bonds Nitrogenous base pairs are joined by hydrogen bonds.

RNA nucleotides contain __________ than DNA nucleotides. a) different purines b) less phosphorus c) less oxygen d) more oxygen e) None of the above.

d) more oxygen Good thinking! RNA uses the sugar ribose, which has one more oxygen atom than the sugar used in DNA (deoxyribose).

The information in DNA tells a cell how to make ... (a) proteins. (b) DNA. (c) tRNA. d) Both (a) and (b). e) (a), (b), and (c).

e) (a), (b), and (c). Excellent! The information in DNA tells how to make every nucleic acid and protein that the cell's parent could make.

All the information stored in DNA is concerned, directly or indirectly, with _________. The process you see here is called transcription. Its products help to build proteins.

making proteins

All kinds of RNA contain _______.

uracil.