Biology Exam 4

How many different kinds of nucleotides are in DNA? A) Two B) Four C) Hundreds or thousands D) Millions

Four

For a mutation to affect the evolution of an animal species, it must occur within A) somatic cells. B) prokaryotic cells. 10 C) diploid cells. D) gametes.

Gametes

Specific segments of DNA that code for a specific protein are called A) chromosomes. B) genes. C) nuclei. D) nucleoli. E) mutations

Genes

________ replication is the process when DNA uses one parental strand and synthesizes a new strand, resulting in each daughter cell having a new and parental DNA strand. A) Conservative B) Semiconservative C) Redundant D) Inversion

Semiconservative

Scientists use the term ____________ to refer to the genetic makeup for that organism. a. allele b. phenotype c. homozygous d. locus e. genotype

genotype

Which of the following causes the unwinding of the DNA double helix? 11 a. DNA polymerase b. DNA helicase c. RNA primer d. Primosome e. RNA polymerase

DNA helicase

How many consecutive mRNA bases are needed to specify an amino acid? A) 3 B) 4 C) 20 D) 64

3

In one strand of DNA, the nucleotide sequence is 5'-A-T-G-C-3'. The complementary sequence in the other strand must be A) 5'-C-G-T-A-3'. B) 5'-A-T-G-C-3'. C) 3'-T-A-C-G-5'. D) 3'-G-C-A-T-5'

3'-T-A-C-G-5'

In a DNA molecule, base pairing occurs between A) adenine and thymine. B) adenine and guanine. C) guanine and uracil. D) thymine and cytosine. E) adenine and uracil.

Adenine and Thymine

Two Martians fall in love and marry. One Martian is homozygous for red eyes and the other is heterozygous. The recessive eye color is purple. What is the probability that they will have a child with purple eyes (assuming Martians have similar genetics to humans)? a. 1/1 b. 1/2 c. 1/4 d. 3/4 e. 0

0

In garden peas, the allele for tall plants is dominant over the allele for short plants. Imagine that a true-breeding tall plant is crossed with a short plant. Then one of their offspring is test crossed. Out of 20 offspring resulting from the test cross, about how 13 many should be tall? A) 0 B) 5 C) 10 D) 15 E) 20

10

If the DNA of a certain organism has guanine as 30% of its bases, then what percentage of its bases are adenine? A) 0% B) 10% C) 20% D) 30% E) 40%

20%

How many bases are in a codon? A) 3 B) 4 C) 20 D) 64

3

If an individual who is homozygous for type B blood marries a heterozygous type A individual, what is the chance that their first child will have type AB blood? A) 0% B) 25% C) 50% D) 75% E) 100%

50%

What is the total number of different possible combinations of bases in a codon? A) 3 B) 4 C) 20 D) 64

64

What is the relationship among DNA, a gene, and a chromosome? A) A chromosome contains hundreds of genes, which are composed of protein. B) A chromosome contains hundreds of genes, which are composed of DNA. C) A gene contains hundreds of chromosomes, which are composed of protein. D) A gene is composed of DNA, but it has no relationship to a chromosome. E) A gene contains hundreds of chromosomes, which are composed of DNA

A chromosome contains hundreds of genes, which are composed of DNA

. Blood typing is often used as evidence in paternity cases in court. In one case, the mother had blood type B and the child had blood type O. Which of the following blood types could the father NOT have? A) A B) B C) AB D) O

AB

The nitrogenous base uracil pairs with A) thymine. B) adenine. C) guanine. D) cytosine. E) uracil

Adenine

When DNA polymerase encounters thymine in the parental strand, what does it add to the growing daughter strand? A) Deoxyribose B) Phosphate group C) Adenine D) Uracil

Adenine

Which of the following represents the possible genotype(s) resulting from a cross between a heterozygous individual (Bb) and one that is homozygous (bb)? a. BB and Bb b. Bb and bb c. BB only d. Bb only e. bb only

Bb and bb

Codominance occurs when A) both of the alleles in a heterozygote are equally expressed phenotypically in an individual. B) expression of two different alleles alternates from one generation to the next. C) a heterozygote expresses an intermediate phenotype. D) offspring exhibit several different phenotypic expressions of a single trait.

Both of the alleles in a heterozygote are equally expressed phenotypically in an individual

Transfer RNA A) is a nucleic acid that carries the code for the primary structure of a protein. B) brings amino acids to the ribosome. C) is a subunit of ribosomes. D) transfers proteins into the nucleus

Brings amino acids to the ribosome

Hershey and Chase concluded that ________ is the hereditary molecule by examining how radioactively labeled molecules moved between a virus and bacteria. A) phospholipids B) protein C) DNA D) Lipids

DNA

The hereditary material present in all cells is A) protein. B) RNA. C) DNA. D) R-strain. E) S-strain.

DNA

Which of the following contains four types of nucleotides but no uracil? A) Ribosomal RNA B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase

DNA

Why does DNA synthesis proceed in a 5′ to 3′ direction? a. DNA polymerases can only add nucleotides to the 3′ end of a polynucleotide strand. b. The 3′ end of the polynucleotide molecule contains more phosphates than the 5′ end. c. DNA unzips in the 5' to 3' direction. d. DNA strands are parallel to each other. e. Chromosomes are aligned in the 5′ to 3′ direction in the nucleus.

DNA polymerases can only add nucleotides to the 3' end of a polynucleotide strand

. Imagine that a DNA sequence of 5'-A-C-G-T-A-C-G-T-3' is altered to 5'-A-C-G-A-C-GT-3'. This could happen as a result of a(n) A) nucleotide substitution mutation. B) deletion mutation. C) insertion mutation. D) inversion. E) translocation.

Deletion mutation

Based on this figure, which molecule would attach to the 5' phosphate end of the DNA strand

Deoxyribose

. Which of the following is TRUE regarding gene expression? A) Gene expression remains constant throughout an organism's life span. B) Different individuals of the same species express all of the same genes. C) Gene expression is not influenced by the environment. D) Different tissues within an organism express different genes.

Different tissues within an organism express different genes

A mating between individuals with different alleles at two loci is known as? a. Parent cross b. Plant breeders cross c. Test cross d. Dihybrid cross e. Monohybrid cross

Dihybrid cross

Regarding the structure of DNA, which of the following is like a spiral staircase? A) Deoxyribose B) Phosphate C) Double helix D) Hydrogen bonds E) Covalent bonds

Double Helix

Complementary base pairs are held together by A) peptide bonds. B) hydrogen bonds. C) disulfide bonds. D) covalent bonds. E) ionic bonds.

Hydrogen Bonds

Regarding the structure of DNA, which of the following joins adenine and thymine and also guanine and cytosine? A) Deoxyribose 5 B) Phosphate C) Double helix D) Hydrogen bonds E) Covalent bonds

Hydrogen Bonds

The two polynucleotide chains in a DNA molecule are attached to each other by A) covalent bonds between carbon atoms. B) hydrogen bonds between bases. C) peptide bonds between amino acids. D) ionic bonds between "R" groups in amino acids. E) covalent bonds between phosphates and sugars.

Hydrogen bonds between bases

Suppose a scientist working on a new drug for cancer developed a chemical that irreversibly breaks the hydrogen bonds in the DNA molecules within cancerous cells but leaves all of the covalent bonds intact. Hydrogen bonds are relatively weak compared to covalent bonds, and they are routinely broken and reformed as the DNA molecule is 4 replicated in a normal cell. Their stability is nonetheless critical for maintaining certain aspects of the structure and function of the DNA molecule. Based on this scenario and your knowledge of DNA, how would this newly discovered chemical affect the "molecule of heredity" in a human cancer cell? A) It would allow the DNA molecule to function normally except during replication. B) It would result in constant DNA replication within the cell. C) It would break the two strands of the DNA molecule apart, preventing it from functioning normally. D) It would break the individual strands of the DNA molecule apart, preventing it from functioning normally.

It would break the two strands of the DNA molecule apart, preventing it from functioning normally

__________ were originally designated the location of a particular gene on the chromosome. a. Loci b. Genotypes c. Phenotypes d. Alleles e. Homozygous

Loci

Imagine that a DNA sequence of 5'-A-C-G-T-A-C-G-T-3' is altered to 5'-A-C-G-C-A-C-G-T-3'. This could happen as a result of a(n) A) nucleotide substitution mutation. B) deletion mutation. C) insertion mutation. D) inversion. E) translocation.

Nucleotide substitution mutation

Imagine that a DNA sequence of 5'-A-C-G-T-A-C-G-T-3' is altered to 5'-A-C-G-C-A-CG-T-3'. This could happen as a result of a(n) A) nucleotide substitution mutation. B) deletion mutation. C) insertion mutation. D) inversion. E) translocation

Nucleotide substitution mutation

A woman with blood type AB and a man with blood type O have three children, one of whom is adopted. The blood types of the children are A, B, and O. What is the blood type of the adopted child? A) A B) B C) O D) Not enough information is provided to answer this question.

O

A nucleotide is made up of a phosphate group, a five-carbon sugar molecule, and a. two of five nitrogeneous bases. b. one of five nitrogeneous bases. c. one of four nitrogeneous bases. d. two of four nitrogeneous bases. e. three of six nitrogeneous bases

One of four nitrogenous bases

Because a newly synthesized DNA molecule contains ____, the replication process is said to be semiconservative. a. two new strands b. one parental strand and one new strand c. two parental strands d. half purines and half pyrimidines e. nucleotides

One parental strand and one new strand

All of the following occur during DNA replication EXCEPT A) separation of parental DNA strands. B) use of parental DNA as a template. C) use of DNA polymerase enzymes. D) synthesis of totally new double-stranded DNA molecules

Separation of parental DNA strands

The way DNA stores information is through the ________ of bases. A) number B) size C) sequence D) different types

Sequence

The sex of most mammals, birds, and insects is determined by a. the temperature. b. the external environment. c. sex chromosomes. d. parental age. e. the internal environment.

Sex chromosomes

Transcription is the process of A) synthesizing a DNA molecule from an RNA template. B) assembling an RNA molecule without a template. C) synthesizing an RNA molecule using a DNA template. D) synthesizing a protein using information from mRNA. E) replicating a single-stranded DNA molecule.

Synthesizing an RNA molecule using a DNA template

If the quantities of the four bases in a DNA molecule are measured, we find that A) A = C and G = T. B) A = G and C = T. C) T = A and C = G. D) no two bases are equal in amount. E) all bases are equal in amount.

T=A and C=G

DNA polymerase, before any proofreading by repair enzymes, makes one mistake for about every A) 1 to 100 base pairs. B) 100 to 1,000 base pairs. C) 10,000 to 1 million base pairs. D) 1 million to 10 million base pairs. E) 100 million to 10 billion base pairs.

Ten thousand to One million base pairs

. Which of the following is TRUE regarding the genetic information in the cells of your body? A) Different kinds of body cells contain different genetic information. B) Each type of body cell contains only the genetic information it needs to be that type of cell. C) The genetic information in almost all of your body cells is identical. D) The genetic information in your body cells changes in a predictable manner as you grow and develop.

The genetic information in almost all of your body cells is identical

What determines the function of the gene product? A) The sequence of bases B) The number of bases C) The sequence of phosphates D) The number of phosphates E) The sequences of deoxyribose

The sequence of bases

When chromosomes replicate A) the two DNA strands separate and each is used as a template for synthesis of a new strand. B) new DNA synthesis occurs in only one location along the entire DNA molecule. C) one strand of the DNA is completely replicated first, and then the second strand is replicated. D) the original DNA is distributed to the two daughter cells, with no new DNA synthesized.

The two DNA strands separate and each is used as a template for synthesis of a new strand

What is an anticodon? A) Four consecutive bases in tRNA B) Three consecutive bases in tRNA C) The beginning of a DNA molecule D) Three consecutive bases in mRNA E) Three consecutive amino acids in a protein

Three consecutive bases in tRNA

What is the anticodon for AUC? A) TAG B) AUC C) GAU D) CUA E) UAG

UAG

Mutations are a source of genetic ________ by which evolutionary change is possible. A) constancy B) stability C) variability D) reproduction

Variability

The function of the promoter is to signal the RNA polymerase A) where to start transcribing the DNA. B) which strand of the DNA to read. C) where to start translating the DNA. D) where to add the first amino acid to the protein

Where to start transcibing the DNA

All of the following combinations are possible in the gametes of an organism that is AaBb EXCEPT A) AB. B) aB. C) aa. D) ab. E) Ab.

aa

A(n) ________ mutation is when one or more nucleotide pairs are lost. A) nucleotide substitution B) insertion C) deletion D) inversion

deletion

A heterozygous fruit fly with normal wings and a gray body (VvBb) is crossed with homozygous flies with vestigial wings and black bodies (vvbb). This type of cross is known as a a. monohybrid cross. b. dihybrid cross. c. polytropic cross. d. true breeding cross. e. chromosomal cross

dihybrid cross

The "one-gene, one-enzyme" hypothesis concluded that A) each allele codes for a single type of protein. B) specific enzymes give rise to specific genes. C) only certain genes function in cells. D) enzymes regulate gene activity. E) DNA is transcribed into RNA, which is translated into protein.

each allele codes for a single type of protein

Semiconservative DNA replication means that A) the old DNA is completely broken down. B) the old DNA remains completely intact. C) A pairs with T and G pairs with C. D) only half of the DNA is replicated. E) each new DNA molecule has half the DNA from the old one

each new DNA molecule has half the DNA from the old one

Which of the following molecules transfers information from the nucleus to the cytoplasm? A) DNA B) mRNA C) tRNA D) Proteins E) Lipids

mRNA

Color blindness is more common in males than in females because a. females need to inherit only one copy of the recessive color blindness allele to express the trait. b. males only need to inherit the recessive maternal color blindness allele to be color blind. c. Color blindness is an autosomal trait. d. all females are hemizygous for the color blindness trait. e. males can only inherit paternal color blindness alleles.

males only need to inherit the recessive maternal color blindness allele to be color blind

Agents that cause mutations are called mutagens. All of the following are examples of mutagens EXCEPT A) ultraviolet radiation. 7 B) X-rays. C) cigarette smoke. D) vitamins.

vitamins