Genetics Exam test questions and
answers graded A+
the branch of genetics concerned with analyzing the structure and function of gene is: -
ANS✅✅Molecular Genetics
Recombinant DNA technology is dependent on a particular class of enzymes, known as
____________ that cuts DNA at specific nucleotide sequences. - ANS✅✅Restriction enzymes
Translation of RNA into proteins occurs: - ANS✅✅In the cytoplasm
The appearance of traits expressed by genes in association with environmental influence is referred
to as the organisms: - ANS✅✅Phenotype
In lilies, white flowers (W) are dominant to purple flowers (w). if two plants that are heterozygous
for flower color are mated, the offspring might have which genotype? - ANS✅✅WW, Ww, ww
In a pea plant that is heterozygous for seed color, what proportion of gametes will carry the
recessive allele? - ANS✅✅1/2
An ideal organism for a geneticist to use as a study organism would possess which of the following
characteristics?
A) A relatively short life cycle
b) a large degree of genetic variation among individuals
c. mating that produce large number of offspring
d. a well-characterized genetic background, karyotype, etc
e. all the above - ANS✅✅All the above
When does one use "reverse genetics: - ANS✅✅When the gene sequence is known, but the
function is not, a scientist creates mutants to observe phenotypes and infer function.
What is the outcome of synapsis, a significant event in meiosis? - ANS✅✅Side-by-side alignment of
homologous chromosomes
,When cells withdraw from the continuous cell cycle and enter a "quiescent" phase, they are said to
be in what stage? - ANS✅✅G0
What occurs in the Pachynema stage of Prophase I - ANS✅✅Each homologous pair contains four
chromatids
Synaptonemal complex starts forming during? - ANS✅✅Zygonema
Mendel performed many types of crosses, including those in which the same genotypes are crossed
but the sexes of the parents are switched. These are known as - ANS✅✅Reciprocal crosses
In a test cross between an individual with an unknown genotype that exhibits the dominant
phenotype and a known homozygous recessive individual, the progeny showed a 1:1 ratio of
dominant to recessive phenotype. the individual unknown genotype is ___________________ for
the gene. - ANS✅✅Heterozygous
In the F2 generation, how many genotypic classes are possible from a trihybrid cross of two
heterozygotes in which the genes involved show complete domiance? - ANS✅✅27 #^3=27
A couple with three girls is expecting a fourth child. The probability that this child is also a girl is -
ANS✅✅1/2
What is the probility of rolling one six-sided die and obtaining a 1 or a 2? -
ANS✅✅1/6+1/6=2/6=1/3
Which of the following is true concerning the inheritance of a dominant trait?
a. every affected person must have at least one affected parent
b. the trait is observed in every generation
c. an affected heterozygote will transmit the allele to half of his or her offspring on average.
d. all the above
e. none of the above - ANS✅✅All the above
, In humans, brown eye color (B) is dominant to blue eyes (b). A brown-eyed man marries a woman
with brown eyes and they have three blue-eyed daughters. What are the genotypes of the man and
the woman? - ANS✅✅Bb and Bb
The chromosome theory of inheritance states that: - ANS✅✅genes are located on chromosomes
In many species, there are two representatives of each chromosome. In such species, the
characteristic number of chromosomes is called the ________ number. It is usually symbolized as
________. - ANS✅✅Diploid, 2n
In an organism with 52 chromosomes, how many bivalents would be expected to form during
meiosis? - ANS✅✅52/2=26
The ant, Myrmecia pilosula, is found in Australia and is named bulldog because of its aggressive
behavior. It is particularly interesting because it carries all its genetic information in a single pair of
chromosomes. In other words, 2n=2 (males are haploid and have just one chromosomes). which of
the following figures would represent the correct configureation of chromosomes in a metaphase I
cell of a female? (Draw this out) Exam 1 Page 4 Number 23 - ANS✅✅A
During Interphase of the cell cycle: - ANS✅✅DNA content essentially doubles
The P value is a quantitative expression of probability that the results of another experiment of the
same size and structure will deviate as much or more from expected results by chance. The greater
the difference between observed and expected results of the experiments - ANS✅✅the greater
the X^2 value and the lower the P value
The probability that two parents with a family of four will have one girl and three boys is: -
ANS✅✅4!/1!3! (1/2)^1*(1/2)^3=4*1/2*1/2)^3=1/4
Polydactyly is expressed when an individual has extra fingers and/or toes. Assume that a man with
six fingers on each hand and six toes on each foot marries a woman with a normal number of digits.
Having extra digits is caused by a dominant allele. The couple has a son with normal hands and feet,
but the couple's second child has extra digits. What is the probability that their next child will have
polydactyly? - ANS✅✅1/2
Assume that a black guinea pig crossed with an albino guinea pig produced 5 black offspring. When
the albino was crossed with a second black one, 4 black and 3 albino offspring were produced. What
genetic explanation would apply to these data? - ANS✅✅Albino=Recessive, Black=dominant
answers graded A+
the branch of genetics concerned with analyzing the structure and function of gene is: -
ANS✅✅Molecular Genetics
Recombinant DNA technology is dependent on a particular class of enzymes, known as
____________ that cuts DNA at specific nucleotide sequences. - ANS✅✅Restriction enzymes
Translation of RNA into proteins occurs: - ANS✅✅In the cytoplasm
The appearance of traits expressed by genes in association with environmental influence is referred
to as the organisms: - ANS✅✅Phenotype
In lilies, white flowers (W) are dominant to purple flowers (w). if two plants that are heterozygous
for flower color are mated, the offspring might have which genotype? - ANS✅✅WW, Ww, ww
In a pea plant that is heterozygous for seed color, what proportion of gametes will carry the
recessive allele? - ANS✅✅1/2
An ideal organism for a geneticist to use as a study organism would possess which of the following
characteristics?
A) A relatively short life cycle
b) a large degree of genetic variation among individuals
c. mating that produce large number of offspring
d. a well-characterized genetic background, karyotype, etc
e. all the above - ANS✅✅All the above
When does one use "reverse genetics: - ANS✅✅When the gene sequence is known, but the
function is not, a scientist creates mutants to observe phenotypes and infer function.
What is the outcome of synapsis, a significant event in meiosis? - ANS✅✅Side-by-side alignment of
homologous chromosomes
,When cells withdraw from the continuous cell cycle and enter a "quiescent" phase, they are said to
be in what stage? - ANS✅✅G0
What occurs in the Pachynema stage of Prophase I - ANS✅✅Each homologous pair contains four
chromatids
Synaptonemal complex starts forming during? - ANS✅✅Zygonema
Mendel performed many types of crosses, including those in which the same genotypes are crossed
but the sexes of the parents are switched. These are known as - ANS✅✅Reciprocal crosses
In a test cross between an individual with an unknown genotype that exhibits the dominant
phenotype and a known homozygous recessive individual, the progeny showed a 1:1 ratio of
dominant to recessive phenotype. the individual unknown genotype is ___________________ for
the gene. - ANS✅✅Heterozygous
In the F2 generation, how many genotypic classes are possible from a trihybrid cross of two
heterozygotes in which the genes involved show complete domiance? - ANS✅✅27 #^3=27
A couple with three girls is expecting a fourth child. The probability that this child is also a girl is -
ANS✅✅1/2
What is the probility of rolling one six-sided die and obtaining a 1 or a 2? -
ANS✅✅1/6+1/6=2/6=1/3
Which of the following is true concerning the inheritance of a dominant trait?
a. every affected person must have at least one affected parent
b. the trait is observed in every generation
c. an affected heterozygote will transmit the allele to half of his or her offspring on average.
d. all the above
e. none of the above - ANS✅✅All the above
, In humans, brown eye color (B) is dominant to blue eyes (b). A brown-eyed man marries a woman
with brown eyes and they have three blue-eyed daughters. What are the genotypes of the man and
the woman? - ANS✅✅Bb and Bb
The chromosome theory of inheritance states that: - ANS✅✅genes are located on chromosomes
In many species, there are two representatives of each chromosome. In such species, the
characteristic number of chromosomes is called the ________ number. It is usually symbolized as
________. - ANS✅✅Diploid, 2n
In an organism with 52 chromosomes, how many bivalents would be expected to form during
meiosis? - ANS✅✅52/2=26
The ant, Myrmecia pilosula, is found in Australia and is named bulldog because of its aggressive
behavior. It is particularly interesting because it carries all its genetic information in a single pair of
chromosomes. In other words, 2n=2 (males are haploid and have just one chromosomes). which of
the following figures would represent the correct configureation of chromosomes in a metaphase I
cell of a female? (Draw this out) Exam 1 Page 4 Number 23 - ANS✅✅A
During Interphase of the cell cycle: - ANS✅✅DNA content essentially doubles
The P value is a quantitative expression of probability that the results of another experiment of the
same size and structure will deviate as much or more from expected results by chance. The greater
the difference between observed and expected results of the experiments - ANS✅✅the greater
the X^2 value and the lower the P value
The probability that two parents with a family of four will have one girl and three boys is: -
ANS✅✅4!/1!3! (1/2)^1*(1/2)^3=4*1/2*1/2)^3=1/4
Polydactyly is expressed when an individual has extra fingers and/or toes. Assume that a man with
six fingers on each hand and six toes on each foot marries a woman with a normal number of digits.
Having extra digits is caused by a dominant allele. The couple has a son with normal hands and feet,
but the couple's second child has extra digits. What is the probability that their next child will have
polydactyly? - ANS✅✅1/2
Assume that a black guinea pig crossed with an albino guinea pig produced 5 black offspring. When
the albino was crossed with a second black one, 4 black and 3 albino offspring were produced. What
genetic explanation would apply to these data? - ANS✅✅Albino=Recessive, Black=dominant
