chapter 10 genetics

what is the average wavelength, in nm, at which RNA absorbed UV light? DNA? Protein?

260; 260; 280

the number of hydrogen bonds between complementary G-C pairs is ___.

3

enter the complementary sequence to the following DNA strand 5'-CGATGAGCC-3'

3'-GCTACTCGG-5'

Match the researcher with the discovery determined that DNA is responsible for transformation in bacteria

Avery, MacLeod, and McCarty

Match the researcher with the discovery discovered regularity in the ratios of different bases in DNA

Chargaff

Match the researcher with the discovery conducted experiments showing that RNA can serve as the genetic material in some viruses

Fraenkel-Conrat and Singer

Match the researcher with the discovery Took X-ray diffraction pictures used in constructing the structure of DNA

Franklin and Wilkins

DNA has unique properties that allow it to accurately retain genetic information, even after multiple rounds of replication. One aspect of DNA that allows it to accurately store genetic information is the base pairing from Chargaff\'s first rule of the four nucleotide bases. If the C content of a DNA molecule is 22%, what are the percentages of the remaining bases?

G=22% A=28% T=28%

Match the researcher with the discovery Demonstrated that heat-killed material from bacteria could genetically transform live bacteria

Griffith

Match the researcher with the discovery identified DNA as the genetic material in bacteriophage

Hershey and Chase

Match the researcher with the discovery determined that DNA contains nitrogenous bases

Kossel

Match the researcher with the discovery Discovered that DNA consists of repeating nucleotides

Levene

Match the researcher with the discovery determined that DNA is acidic and high in phosphorus

Miescher

Match the researcher with the discovery Worked out the helical structure of DNA by building models

Watson and Crick

the left-handed form of DNA is the ___.

Z-DNA

what is a purine?

a base with two rings adenine and guanine

The bacterium Streptococcus pneumoniae has a virulent S strain and a nonvirulent R strain. The S strain is lethal to mice. The S strain contains a chemical factor that can transform the R strain to be virulent. The diagram shows a series of experiments conducted by injecting combinations of these strains into mice to identify the transforming factor. If DNA is the transforming factor, match the expected results of each experiment by placing the appropriate mouse image. a. R strain (nonvirulent) b. S strain (virulent) c. heat-treated S strain d. R strain and heat-treated S strain e. R strain and heat-treated S strain with polysaccharides, lipids, RNA, and proteins destroyed f. R strain and heat-treated S strain with polysaccharides, lipids, RNA, proteins, and DNA destroyed

a. alive b. dead c. alive d. dead e. dead f. alive

James Watson and Francis Crick used the X-ray diffraction image taken by Rosalind Franklin to deduce structural properties of B-form DNA. What findings did Watson and Crick make from this image? a. has a consistent diameter b. shaped like a helix c. stores biological information d. includes 10 base pairs per repeat e. contains equal proportions of purines and pyrimidines

a. has a consistent diameter b. shaped like a helix d. includes 10 base pairs per repeat

select each of the characteristics that are key features of genetic material. a. it must be able to replicate and transmit to progeny b. it must encode the blueprint to form proteins and other structures c. it must differentiate in each cell type d. it must have observable characteristics that are heritable e. it must be variable through infrequent mutation

a. it must be able to replicate and transmit to progeny b. it must encode the blueprint to form proteins and other structures e. it must be variable through infrequent mutation

what evidence supports the hypothesis that RNA was the genetic material early in evolutionary history? a. some viruses have RNA genomes b. RNA has been isolated from more ancient sources than DNA c. some archaea have RNA genomes d. RNA can self-replicate what is the reason scientists think DNA was selected over RNA as the most common genetic material?

a. some viruses have RNA genomes d. RNA can self-replicate DNA is more stable than RNA

In 1953, the scientists James Watson and Francis Crick published their landmark findings on the structure of DNA. Watson and Crick deduced the structure of DNA by unifying evidence that they collected from several scientists who were also seeking to answer this important question. Identify the pieces of evidence describing the features of DNA that Watson and Crick used to determine the structure of DNA. a. the sugar-phosphate backbones of each DNA helix run antiparallel to one another b. a purine base forms covalent bonds with a pyrimidine base located on the opposite DNA helix c. the two chains are parallel, both running in a 5' to 3' direction d. a purine base forma hydrogen bonds to pair with a pyrimidine base located on the opposite DNA strand. Specifically A pairs with T and C pairs with G e. the diameter of the DNA double helix is 2 nanometers with each purine-pyrimidine base pair spanning an equivalent distance between the two chains f. DNA forms a right-handed double helical structure with two polynucleotide chains coiled around a central axis

a. the sugar-phosphate backbones of each DNA helix run antiparallel to one another d. a purine base forma hydrogen bonds to pair with a pyrimidine base located on the opposite DNA strand. Specifically A pairs with T and C pairs with G e. the diameter of the DNA double helix is 2 nanometers with each purine-pyrimidine base pair spanning an equivalent distance between the two chains f. DNA forms a right-handed double helical structure with two polynucleotide chains coiled around a central axis

the major contribution of Franklin and Wilkins to the study of DNA was ___.

an X-ray diffraction pattern

which of the following relations will be found in the percentages of bases of double-stranded DNA molecule? a. A+T=G+C b. A/T=G/C c. (A+G)/(C+T)=1 d. A+G=C+T e. A/G=C/T

b. A/T=G/C c. (A+G)/(C+T)=1 d. A+G=C+T

what characteristic is not necessary for a molecule that is the genetic material? a. it must contain complex information b. it must perform the action associated with the phenotype c. it must be variable d. it must encode the phenotype e. it must have the ability to replicate faithfully

b. it must perform the action associated with the phenotype

which of the following statements describes purines and pyrimidines in DNA molecules? a. pyrimidines form hydrogen bonds with pyrimidines b. purines form hydrogen bonds with pyrimidines c. purines form covalent bonds with pyrimidines d. purines consist of a two-ring structure e. thymine and cytosine are purines

b. purines form hydrogen bonds with pyrimidines d. purines consist of a two-ring structure

which of the following was not shown by Watson and Cricks model of DNA? a. the strands run in opposite directions b. the bases face outside for easy access c. the helices are right-handed d. there could be a means for DNA to easily replicate itself e. one adenine would pair with one thymine

b. the bases face outside for easy access

Identify the key structural features of a DNA molecule. a. DNA is most often found as a left-handed helix, commonly referred to as A-DNA b. DNA contains the nucleotide bases adenine, thymine, guanine, cytosine, and uracil c. DNA bases are always paired using Watson-Crick base pairing d. the backbone of DNA is made of a sugar and a phosphate molecule e. strong ionic bonds are hydrophobic interaction hold DNA together f. DNA strands are antiparallel and include a 5' and and a 3' end

c. DNA bases are always paired using Watson-Crick base pairing d. the backbone of DNA is made of a sugar and a phosphate molecule f. DNA strands are antiparallel and include a 5' and and a 3' end

There are two types of nucleic acids, DNA and RNA. Nearly all organisms use DNA, not RNA, as the central repository for genetic information. Choose the statements that explain this phenomenon. a. DNA is flexible and forms complex catalytic structures b. DNA contains a hydroxyl group at the 2' carbon c. DNA has a double stranded structure that ensures an accurate mechanism of duplication d. DNA contains cytosine as one of its nitrogenous bases e. DNA is more resistant against enzymes that break down nucleic acids

c. DNA has a double stranded structure that ensures an accurate mechanism of duplication e. DNA is more resistant against enzymes that break down nucleic acids

what is the key feature of DNA that allows it to be copied?

complementary base pairing

Which of the following single-stranded DNA sequences is most likely to form a stem-loop structure? a. TCATAGGCGCCGTTCA b. TAAGTACATTACCCCG c. GCAGGGACTCCGACGT d. AGGAGCACTGGCTCCT

d. AGGAGCACTGGCTCCT

Which of these is an example of a sequence of bases in an RNA molecule that will produce a hairpin structure? a. TGCGATACTCATCGCA b. AAUAAUUUCGGAGCGC c. AUCGGGCCCAAGUCG d. UGCGAUACUCAUCGCA e. CGCGCAAAGCGCG

d. UGCGAUACUCAUCGCA e. CGCGCAAAGCGCG

a structure formed by a single-stranded DNA or RNA molecule that has complementary sequence is a/an ___.

hairpin

the sugar in DNA is called deoxyribose because it ___.

is missing a 2'-OH group

a strong covalent bond between adjacent nucleotides is a/an ___.

phosphodiester bond

suppose the following data is collected for an unknown nucleic acid: A = 28% C = 18% G = 26% T = 0% U = 28% identify the unknown nucleic acid

single-stranded RNA

in experiments involving tobacco mosaic virus, Fraenkel-Conrat and Signer demonstrated ___.

that in some cases RNA can be the genetic material

In the Hershey-Chase experiment, DNA was demonstrated to be the genetic material because the 32P label for DNA localized to ___.

the bacterial pellet

what does the term antiparallel mean?

the strands run in opposite directions and the 5' end of one strand is opposite the 3' end of the second strand

a key discovery leading to the structure of DNA was done by Chargaff. he found that ___.

the tetranucleotide hypothesis was false and that the amount of A equals the amount of T, and the amount of G equals the amount of C

What did Griffith discover with his experiments?

the transforming principle in bacteria

what contribution did James Watson and Francis Crick make to our understanding of DNA?

they pieced together the available evidence and modeled the structure of DNA

in Avery, MacLeod, and McCarthy's experiments homogenates from heat-killed bacteria were treated with different enzymes, and then the ability of those homogenates to transform bacteria was assayed. Under which condition would transformation not occur?

treatment with DNase