Test Bank - Introduction to Genetic Analysis, 12th Edition (Griffiths), Chapter 1-
20 .150 practice questions with answers and rationales
Introduction to Genetic Analysis, 12th Edition (Griffiths) - Practice Questions by
Chapter
Chapter 1: The Genetics Revolution
Question 1
The early 1900s was an important period for genetics due to which of the
following major events?
A) the rediscovery of Gregor Mendel's scientific findings
B) Watson and Crick solving the structure of DNA
C) Walter Sutton and Theodore Boveri hypothesizing that chromosomes are the
hereditary elements
D) the rediscovery of Mendel's findings and Sutton/Boveri hypothesizing that
chromosomes are hereditary elements
E) All of the answer options are correct
Correct Answer: E
Rationale: The rediscovery of Mendel's work in 1900 (by Correns, de Vries, and
von Tschermak) and the chromosomal theory of inheritance proposed by Sutton
,and Boveri were both critical events in early 20th-century genetics, establishing
the foundation for modern genetics .
Question 2
A sample of normal double-stranded DNA was found to have a guanine content of
18%. What is the expected proportion of adenine?
A) 9%
B) 32%
C) 36%
D) 68%
E) 82%
Correct Answer: B
Rationale: According to Chargaff's rules, in double-stranded DNA, adenine pairs
with thymine (A = T) and guanine pairs with cytosine (G = C). If G = 18%, then C =
18%. Together G+C = 36%, so A+T = 64%. Since A = T, A = 32% .
Question 3
,In one strand of DNA, the nucleotide sequence is 5'-ATGC-3'. The complementary
sequence in the other strand must be:
A) 3'-ATGC-5'
B) 3'-TACG-5'
C) 5'-ATCG-3'
D) 5'-CGTA-3'
E) 5'-TACG-3'
Correct Answer: B
Rationale: Complementary base pairing rules: A pairs with T, G pairs with C. The
strands are antiparallel, so the complementary strand runs 3' to 5' opposite the
given 5' to 3' sequence. Starting with 5'-ATGC-3', the complementary bases are
TACG, read 3' to 5', so 3'-TACG-5' .
Question 4
How many different DNA molecules that are eight-nucleotide-pairs long are
theoretically possible?
A) 24
B) 32
, C) 64
D) 256
E) 65,536
Correct Answer: E
Rationale: At each position along the DNA molecule, there are 4 possible base
pairs (A-T, T-A, G-C, C-G). For a sequence of n base pairs, the number of possible
sequences is 4^n. For n = 8, 4^8 = 65,536 possible molecules .
Question 5
Which of the following is/are TRUE about genes?
A) Genes are located on chromosomes
B) Genes come in variants known as alleles
C) Genes usually encode protein products
D) All of the answer options are correct
E) None of the answer options is correct
Correct Answer: D
20 .150 practice questions with answers and rationales
Introduction to Genetic Analysis, 12th Edition (Griffiths) - Practice Questions by
Chapter
Chapter 1: The Genetics Revolution
Question 1
The early 1900s was an important period for genetics due to which of the
following major events?
A) the rediscovery of Gregor Mendel's scientific findings
B) Watson and Crick solving the structure of DNA
C) Walter Sutton and Theodore Boveri hypothesizing that chromosomes are the
hereditary elements
D) the rediscovery of Mendel's findings and Sutton/Boveri hypothesizing that
chromosomes are hereditary elements
E) All of the answer options are correct
Correct Answer: E
Rationale: The rediscovery of Mendel's work in 1900 (by Correns, de Vries, and
von Tschermak) and the chromosomal theory of inheritance proposed by Sutton
,and Boveri were both critical events in early 20th-century genetics, establishing
the foundation for modern genetics .
Question 2
A sample of normal double-stranded DNA was found to have a guanine content of
18%. What is the expected proportion of adenine?
A) 9%
B) 32%
C) 36%
D) 68%
E) 82%
Correct Answer: B
Rationale: According to Chargaff's rules, in double-stranded DNA, adenine pairs
with thymine (A = T) and guanine pairs with cytosine (G = C). If G = 18%, then C =
18%. Together G+C = 36%, so A+T = 64%. Since A = T, A = 32% .
Question 3
,In one strand of DNA, the nucleotide sequence is 5'-ATGC-3'. The complementary
sequence in the other strand must be:
A) 3'-ATGC-5'
B) 3'-TACG-5'
C) 5'-ATCG-3'
D) 5'-CGTA-3'
E) 5'-TACG-3'
Correct Answer: B
Rationale: Complementary base pairing rules: A pairs with T, G pairs with C. The
strands are antiparallel, so the complementary strand runs 3' to 5' opposite the
given 5' to 3' sequence. Starting with 5'-ATGC-3', the complementary bases are
TACG, read 3' to 5', so 3'-TACG-5' .
Question 4
How many different DNA molecules that are eight-nucleotide-pairs long are
theoretically possible?
A) 24
B) 32
, C) 64
D) 256
E) 65,536
Correct Answer: E
Rationale: At each position along the DNA molecule, there are 4 possible base
pairs (A-T, T-A, G-C, C-G). For a sequence of n base pairs, the number of possible
sequences is 4^n. For n = 8, 4^8 = 65,536 possible molecules .
Question 5
Which of the following is/are TRUE about genes?
A) Genes are located on chromosomes
B) Genes come in variants known as alleles
C) Genes usually encode protein products
D) All of the answer options are correct
E) None of the answer options is correct
Correct Answer: D
