(Pierce, 2020), Chapter 1-26 | 9781319216801 All Chapters
with Answers and Rationals
When did Mendel's work become appreciated? - ANSWER: Gregor Mendel put forth the basic
principles of inheritance, publishing
his findings in 1866. The significance of his work did not
become widely appreciated until 1900.
Which of the following factors did not contribute to Mendel's
success in his study of heredity?
a. His use of the pea plant
b. His study of plant chromosomes
c. His adoption of an experimental approach
d. His use of mathematics - ANSWER: b. His study of plant chromosomes
Gene - ANSWER: A genetic factor (region of DNA) that
helps determine a characteristic
Allele - ANSWER: One of two or more alternate forms
of a gene
Locus - ANSWER: Specific place on a chromosome
occupied by an allele
Genotype - ANSWER: Set of alleles possessed by an
individual organism
Heterozygote - ANSWER: An individual organism possessing two
different alleles at a locus
Homozygote - ANSWER: An individual organism possessing two
of the same alleles at a locus
Phenotype or trait - ANSWER: The appearance or manifestation of
a character
Character or An attribute or feature
characteristic - ANSWER: An attribute or feature
Genotype and Phenotype? - ANSWER: Each phenotype results from a genotype developing within a
specific environment. The genotype, not the phenotype, is
inherited.
Concept Check 2
Distinguish among the following terms: locus, allele, genotype. - ANSWER: A locus is a place on a
chromosome where genetic
information encoding a trait is located. An allele is a copy of a
gene that encodes a specific trait. A gene is an inherited factor
that determines a trait.
The principle of segregation? - ANSWER: The principle of segregation states that each individual
organism
possesses two alleles that can encode a characteristic. These alleles
segregate when gametes are formed, and one allele goes into
, each gamete.The concept of dominance states that, when the two
alleles of a genotype are different, only the trait encoded by one
of them—the "dominant" allele—is observed.
Concept Check 3
How did Mendel know that each of his pea plants carried two alleles
encoding a characteristic? - ANSWER: Because the traits for both alleles appeared in the F2 progeny
The Punnett square? - ANSWER: The Punnett square is a shorthand method of predicting the
genotypic
and phenotypic ratios of progeny from a genetic cross.
Concept Check 4
If an F1 plant depicted in Figure 3.4 is backcrossed to the parent
with round seeds, what proportion of the progeny will have wrinkled
seeds? (Use a Punnett square.)
a. 3/4
b. 1/2
c. 1/4
d. 0 - ANSWER: d. 0
The multiplication rule? - ANSWER: The multiplication rule states that the probability of two or more
independent events occurring together is calculated by multiplying
their independent probabilities.
events occurring is calculated by adding their probabilities.
Concept Check 5
If the probability of being blood-type A is 1/8 and the probability of
blood-type O is 1/2, what is the probability of being either blood-type
A or blood-type O?
a. 5/8
b. 1/2
c. 1/8
d. 1/16 - ANSWER: a. 5/8
A testcross? - ANSWER: A testcross is a cross between an individual with an unknown
genotype and one with a homozygous recessive genotype. The
outcome of the testcross can reveal the unknown genotype
Incomplete dominance? - ANSWER: Incomplete dominance is exhibited when the heterozygote has a
phenotype intermediate between the phenotypes of the two
homozygotes. When a trait exhibits incomplete dominance, a
cross between two heterozygotes produces a 1 : 2 : 1 phenotypic
ratio in the progeny.
Concept Check 6
If an F1 individual in Figure 3.8 is used in a testcross, what
proportion of the progeny from this cross will be white?
a. All the progeny
b. 1/2
c. 1/4
d. 0 - ANSWER: b. 1/2
The principle of independent assortment? - ANSWER: The principle of independent assortment states
that genes encoding
different characteristics separate independently of one
another when gametes are formed, owing to the independent separation