Chapter 14 & 16 Review

What fraction of the offspring from a cross between two animals with the genotype AaBbCc are expected to be homozygous recessive for the three traits? a. 1/64 b. 1/4 c. 1/8 d. 1/16

a. 1/64

Radioactive thymine is added to media containing one actively dividing E. coli bacterium. Which of the following outcomes would be seen after a single cell division? a. DNA in both daughter cells would be radioactive. b. One of the daughter cells, but not the other, would have radioactive DNA. c. Neither of the two daughter cells would be radioactive. d. All four bases of the DNA would be radioactive.

a. DNA in both daughter cells would be radioactive.

The lagging strand is characterized by a series of short segments of DNA (Okazaki fragments) that are joined together to form a finished lagging strand. The experiments that led to the discovery of Okazaki fragments gave evidence for which of the following ideas? a. DNA polymerase synthesizes leading and lagging strands during replication only in one direction. b. DNA is a polymer consisting of four monomers: adenine, thymine, guanine, and cytosine. c. DNA is the genetic material that requires removal of short RNA segments to be functional. d. Bacterial replication is fundamentally different from eukaryotic replication.

a. DNA polymerase synthesizes leading and lagging strands during replication only in one direction.

Which of the following structural characteristics is most critical for the association between histones and DNA? a. Histones are positively charged. b. There are at least five different histone proteins in every eukaryote. c. Histones are small proteins. d. Histones are highly conserved (that is, histones are very similar in every eukaryote).

a. Histones are positively charged.

When a dominant allele coexists with a recessive allele in a heterozygote individual, how do they interact with each other? a. They do not interact at all. b. The dominant allele prevents transcription of the recessive allele. c. The dominant allele prevents expression of the recessive allele by an unknown mechanism.

a. They do not interact at all.

During ____________ of the cell cycle, the cell grows and replicates both its organelles and its chromosomes. a. interphase b. mitosis c. cytokinesis d. prophase

a. interphase (Interphase can be divided into three phases: G1 phase, S phase, and G2 phase. During all three phases of interphase, a cell grows by producing proteins and cytoplasmic organelles. Duplication of the chromosomes, crucial for eventual division of the cell, occurs entirely during the S phase of interphase. Cell division occurs during M phase, which can be divided into two stages: mitosis and cytokinesis.)

Which of the following lists represents the order of increasingly higher levels of organization of chromatin? a. nucleosome, 30-nm chromatin fiber, looped domain b. 30-nm chromatin fiber, nucleosome, looped domain c. nucleosome, looped domain, 30-nm chromatin fiber d. looped domain, 30-nm chromatin fiber, nucleosome

a. nucleosome, 30-nm chromatin fiber, looped domain

Which of the following characteristics of DNA allows it to carry a vast amount of hereditary information? a. sequence of bases b. phosphate-sugar backbones c. complementary pairing of bases d. antiparallel orientation

a. sequence of bases

When Mendel set up a Parental (P) cross between true breeding purple and white flowered plants to generate the F1 and then allowed the F1 to self-pollinate to generate the F2 he saw a dominant to recessive ratio of 3:1. What phenotypic ratio would be expected if he crossed the F1 with the original purple parent? a. 9:3:3:1 b. 4:0 c. 3:1 d. 1:1

b. 4:0

Which of the following best describes how an individual with genotype AaBbCCDdEE can make gametes with eight different genotypes? a. crossing over during prophase I leads to increased genetic diversity b. the inheritance of a particular copy of one chromosome does not affect the inheritance of a different chromosome c. dominant alleles tend to be inherited together d. mutations during meiosis form new alleles that are incorporated into the gametes

b. the inheritance of a particular copy of one chromosome does not affect the inheritance of a different chromosome

Griffith's experiments with S. pneumoniae were significant because they showed that traits could be transferred from one organism to another. What else did he find that was significant? a. protein could not be the genetic material b. the transferred traits were heritable c. heat kills bacteria d. DNA was the genetic material e. a virus made the bacteria pathogenic

b. the transferred traits were heritable (The fact that offspring of transformed bacteria also showed the pathogenic trait meant that the transforming agent had to be involved with the genetic material.)

Hershey and Chase set out to determine which type of molecule is used for genetic inheritance. They completed a series of experiments where E. coli was infected by a T2 virus. Which molecular component of the T2 virus ended up inside the cell? a. ribosome b. protein c. DNA d. RNA

c. DNA

Which of the following statements correctly describes the structure of chromatin? a. Both heterochromatin and euchromatin are found in the cytoplasm. b. Heterochromatin is composed of DNA, whereas euchromatin is made of DNA and RNA. c. Heterochromatin is highly condensed, whereas euchromatin is less compact. d. Euchromatin is not transcribed, whereas heterochromatin is transcribed.

c. Heterochromatin is highly condensed, whereas euchromatin is less compact.

A diploid animal is dihybrid at the Head shape (H) and Tail length (T) loci. Which of the following gamete genotypes can it produce? a. HhTt b. HHTT c. Ht d. Hh

c. Ht

Which of the following statements about the law of independent assortment is correct? a. It is the consequence of having two copies of each chromosome in somatic cells and one copy in gametes. b. It is the reason that dominant alleles are visible in the organism's phenotype. c. It describes the inheritance of different genes relative to one another. d. It describes the inheritance of different alleles relative to one another.

c. It describes the inheritance of different genes relative to one another.

Which of the following statements correctly explains the observation that parents with two different phenotypes produced offspring with a phenotype that is a blend of the two parental varieties? a. Both of the parents are homozygous at that locus b. Neither of the parental alleles is expressed in the offspring c. Neither of the parental alleles is dominant over the other. d. Both of the parents have dominant alleles.

c. Neither of the parental alleles is dominant over the other.

Mendel crossed true breeding yellow-seeded and green-seeded pea plants and then allowed the offspring to self-pollinate to produce an F2 generation. The results were as follows: 6,022 yellow and 2,001 green (8,023 total). Which of the following statements correctly describes the relationship of the allele for green seeds to the allele for yellow seeds? a. The two alleles exhibit incomplete dominance. b. The two alleles are codominant. c. The green allele is recessive to the yellow allele. d. The green allele is dominant to the yellow allele.

c. The green allele is recessive to the yellow allele.

Which of the following types of molecules help to hold the DNA strands apart while they are being replicated? a. DNA polymerase b. primase c. single-strand DNA binding proteins d. ligase

c. single-strand DNA binding proteins

Feather color in budgies is determined by two different genes, Y for pigment on the outside of the feather, and B for pigment on the inside of the feather. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white. Two blue budgies were crossed. Over the years, they produced 22 offspring, five of which were white. What are the most likely genotypes for the two blue budgies? a. yyBB and yyBb b. yyBb and yybb c. yyBb and yyBb d. yyBB and yyBB

c. yyBb and yyBb

In pea plants, the tall phenotype is dominant to the dwarf phenotype. If a heterozygous pea plant is crossed with a homozygous tall pea plant, what is the probability that the offspring will be dwarf in size? a. 1 b. 0.25 c. 0.5 d. 0

d. 0

In human blood types, Rh positive is a trait that shows simple dominance over Rh negative. The Rh phenotype is recorded by stating "positive" or "negative" after the individuals ABO blood type. A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Which of the following phenotypes is possible for the father? a. A negative b. AB negative c. O negative d. B positive

d. B positive

Which of the following investigators was (were) responsible for determining that DNA contains equal amounts of adenine and thymine, and equal amounts of guanine and cytosine? a. Matthew Meselson and Franklin Stahl b. Alfred Hershey and Martha Chase c. Oswald Avery, Maclyn McCarty, and Colin MacLeod d. Erwin Chargaff

d. Erwin Chargaff

What are the repetitive DNA sequences present at the ends of eukaryotic chromosomes called? a. sarcomeres b. chromomeres c. centromeres d. telomeres e. polypeptides

d. telomeres (Telomeres consist of many copies of a short DNA sequence that is bound by specific proteins.)

Which of the following is most likely to result if a cell is unable to produce histone proteins? a. topoisomerases in the 300-nm fiber scaffolding would not need to be as active b. the 30-nm fiber pack more tightly and become thinner than 30 nm c. there would be an increase in the amount of DNA produced during replication d. the cell's DNA could not be packed into its nucleus

d. the cell's DNA could not be packed into its nucleus

Consider pea plants with the genotypes GgTt and ggtt. How many types of gametes can be produced by each of these two plants? a. one, two b. two, one c. one, one d. four, two e. four, one

e. four, one