Biology B – primavera Exam Questions
with Correct Answers.
In some situations , when two purple-flowered pea plants reproduce , the offspring can
have purple or white flowers . When this experiment is run repeatedly , it is discovered
that three-fourths of the offspring have purple flowers and one-fourth of the offspring
have white flowers .
What would happen if this experiment were run only once ? - Answer-The experiment
would result in a plant with either purple or white flowers . The conclusion would depend
on this single result and would not be accurate .
What statement is true about heterozygous organisms ? - Answer-Heterozygous
organisms are more genetically diverse than homozygous organisms.
A type of insect can be red or black . Red is the dominant trait and is represented by a
capital R . Identify the Punnett square that illustrates all offspring being homozygous
recessive for a trait . - Answer-all lowercase r
Parent A is homozygous dominant for curly hair , and Parent B is homozygous
recessive for straight hair .
What is the expected phenotype of the offspring ? - Answer-curly hair
What can be shown by a dihybrid cross experiment ? - Answer-The inheritance of one
trait does not affect the chance of inheriting another .
A dihybrid cross experiment produces offspring of four different types in the F2
generation . What is the predicted ratio of the four phenotypes in the offspring ? -
Answer-9:3:3:1
Which statement best describes a monohybrid cross ? - Answer-a cross in which traits
of several different characteristics are studied
Twenty-five percent of the possible offspring for a cross are homozygous dominant .
What genotype do each of the parents have ? - Answer-heterozygous
In pea plants , green seeds are dominant (Y) , and yellow seeds are recessive (y) . The
following Punnett square shows a cross for seed color . - Answer-100 percent
What is the ratio of tall offspring to short offspring ? - Answer-3:1
What valuable information was gained from Mendel's dihybrid crosses ?
Select all that apply . - Answer-inheritance of one trait does not affect inheritance of
another .
,statistical and probability methods can be used to determine how likely an offspring is to
inherit certain traits .
Dihybrid cross experiments led Mendel to propose his law of independent assortment .
Which statement best describes this law ? - Answer-the law of independent assortment
states that alleles of different genes are inherited independently of each other .
Read the following statement .
A dihybrid cross experiment is carried out in pea plants . The traits being observed are
flower color and stem length . In the F2 generation , 81 plants have purple flowers and
long stems , 27 plants have purple flowers and short stems , 27 plants have white
flowers and long stems , and 3 plants have white flowers and short stems .
Which traits are recessive ? - Answer-white flowers , short stem
A dihybrid cross experiment is carried out in pea plants . Which statements are true ?
Select all that apply . - Answer-the f1 generation will all have both dominant phenotypes
.
the f2 generation will be a mixture of four different phenotypes .
A scientist is studying two traits on a fruit fly . She discovers that these are most often
inherited together .
What can be said about these traits ? - Answer-They are on the same chromosome and
are linked together .
why might a Punnett square predicting the results of a dihybrid cross give incorrect
results ? - Answer-The two genes are on the same chromosome, making some
combinations less likely than others .
which is an example of the environment affecting gene expression ? - Answer-some
genes being turned off in warm temperatures
In which situation are you likely to find a trait with only one allele ? - Answer-genes
found in the DNA of the mitochondria
Multiple alleles for a gene exist in a population . Which of these statements describes
how alleles are inherited ? - Answer-An individual can only inherit two alleles for a
gene .
Which of the following facts was unknown to Gregor Mendel ? - Answer-alleles for
genes are found on chromosomes
Why are linked traits inconsistent with Mendel's laws ? - Answer-linked traits are likely to
be inherited together. this is not consistent with mendel's law of independent
assortment.
,What is an effect that results when two genes are located side by side on the same
chromosome ? - Answer-Punnett squares can give incorrect predictions of inheritance.
What statement is true ? - Answer-a diploid organism most often has two alleles for a
trait.
What is epistasis ? - Answer-traits where one gene interferes with the effect of another
What is an example of an environmental effect on phenotype ? - Answer-the gender of
sea turtles being affected by the temperature
How many alleles are typically found for mitochondrial genes ? - Answer-1
Which of these are genes that have more than two alleles ? - Answer-the c gene for
melanin production in rabbit coats
Multiple alleles for a gene make populations more diverse .
What are the benefits of this ? Select all that apply . - Answer-it makes it more likely that
a population will survive environmental changes .
if a population encounters a new disease , some of the individuals may be immune to it .
Which of the following statements about polygenic inheritance are true ?
Select all that apply . - Answer-Each gene only contributes a small part to the
phenotype .
When a high number of genes is involved , the number of possible phenotypes is also
high .
What effects can epistasis have on polygenic inheritance ? Select all that apply . -
Answer-a gene can modify the effect of another gene
a gene can mask the effect of another gene
genes can combine to produce entirely new traits
A lab technician observes that the red blood cells in a blood sample display
codominance . What alleles does the person who provided the blood sample have ? -
Answer-iA and iB
A lab technician observes that the red blood cells in a blood sample have surface
antigen B . What alleles does the person who provided the blood sample have ? -
Answer-iBiB or iBi
What are characteristics of polygenic traits ?
Select all that apply . - Answer-on a histogram , traits distribute on a bell-shaped curve
traits are continuous across a range
Which factor determines if someone has brown eyes or green eyes ? - Answer-several
genes acting together
, A few genes are responsible for melanin pigmentation in human skin . Each gene has
one allele that codes for melanin production and one allele that does not .
Which of the following are true ? Select all that apply . - Answer-the combination of
alleles determines how pigmented the skin will be
each allele only contributes a small amount to the phenotype
How can epistatic interactions affect the number of phenotypes that can appear ?
Select all that apply . - Answer-Epistasis can mask genes and prevent them from
affecting the phenotypes .
Epistasis can create new phenotypes .
Epistasis can modify existing phenotypes .
What is the difference between blood types in the ABO blood type system ? - Answer-
antigens on red blood cells
Two people have the genotype IAIB . Of the following options , what possible genotypes
could their children have ? - Answer-iBiB
iAiA
iAiB
A person has blood type B .
What combination of alleles could she have to give her this blood type ?
Select all that apply . - Answer-iBi
iBiB
Two parents both have homozygous genotypes . One parent has blood type A and the
other has blood type B . What genotype can be expected in all of their children ? -
Answer-AB
Blood type is an example of which of the following ?
Select all that apply . - Answer-a situation in which a gene has three or more alleles
a situation in which more than one allele for a trait is dominant
A father is color blind , and a mother is homozygous dominant for normal vision . What
is the probability that one of their offspring will be color blind ? - Answer-0%
Why are males more likely than females to have an X-linked disorder ? - Answer-males
have only one x chromosome ; thus , if a recessive allele is inherited, it is always
expressed .
Which of these describe an inheritance pattern of autosomal genetic disorders ? Select
all that apply . - Answer-for an autosomal dominant disorder to be expressed , just one
copy of the abnormal allele must be inherited .
for an autosomal recessive disorder to be expressed , two copies of the abnormal allele
must be inherited .
with Correct Answers.
In some situations , when two purple-flowered pea plants reproduce , the offspring can
have purple or white flowers . When this experiment is run repeatedly , it is discovered
that three-fourths of the offspring have purple flowers and one-fourth of the offspring
have white flowers .
What would happen if this experiment were run only once ? - Answer-The experiment
would result in a plant with either purple or white flowers . The conclusion would depend
on this single result and would not be accurate .
What statement is true about heterozygous organisms ? - Answer-Heterozygous
organisms are more genetically diverse than homozygous organisms.
A type of insect can be red or black . Red is the dominant trait and is represented by a
capital R . Identify the Punnett square that illustrates all offspring being homozygous
recessive for a trait . - Answer-all lowercase r
Parent A is homozygous dominant for curly hair , and Parent B is homozygous
recessive for straight hair .
What is the expected phenotype of the offspring ? - Answer-curly hair
What can be shown by a dihybrid cross experiment ? - Answer-The inheritance of one
trait does not affect the chance of inheriting another .
A dihybrid cross experiment produces offspring of four different types in the F2
generation . What is the predicted ratio of the four phenotypes in the offspring ? -
Answer-9:3:3:1
Which statement best describes a monohybrid cross ? - Answer-a cross in which traits
of several different characteristics are studied
Twenty-five percent of the possible offspring for a cross are homozygous dominant .
What genotype do each of the parents have ? - Answer-heterozygous
In pea plants , green seeds are dominant (Y) , and yellow seeds are recessive (y) . The
following Punnett square shows a cross for seed color . - Answer-100 percent
What is the ratio of tall offspring to short offspring ? - Answer-3:1
What valuable information was gained from Mendel's dihybrid crosses ?
Select all that apply . - Answer-inheritance of one trait does not affect inheritance of
another .
,statistical and probability methods can be used to determine how likely an offspring is to
inherit certain traits .
Dihybrid cross experiments led Mendel to propose his law of independent assortment .
Which statement best describes this law ? - Answer-the law of independent assortment
states that alleles of different genes are inherited independently of each other .
Read the following statement .
A dihybrid cross experiment is carried out in pea plants . The traits being observed are
flower color and stem length . In the F2 generation , 81 plants have purple flowers and
long stems , 27 plants have purple flowers and short stems , 27 plants have white
flowers and long stems , and 3 plants have white flowers and short stems .
Which traits are recessive ? - Answer-white flowers , short stem
A dihybrid cross experiment is carried out in pea plants . Which statements are true ?
Select all that apply . - Answer-the f1 generation will all have both dominant phenotypes
.
the f2 generation will be a mixture of four different phenotypes .
A scientist is studying two traits on a fruit fly . She discovers that these are most often
inherited together .
What can be said about these traits ? - Answer-They are on the same chromosome and
are linked together .
why might a Punnett square predicting the results of a dihybrid cross give incorrect
results ? - Answer-The two genes are on the same chromosome, making some
combinations less likely than others .
which is an example of the environment affecting gene expression ? - Answer-some
genes being turned off in warm temperatures
In which situation are you likely to find a trait with only one allele ? - Answer-genes
found in the DNA of the mitochondria
Multiple alleles for a gene exist in a population . Which of these statements describes
how alleles are inherited ? - Answer-An individual can only inherit two alleles for a
gene .
Which of the following facts was unknown to Gregor Mendel ? - Answer-alleles for
genes are found on chromosomes
Why are linked traits inconsistent with Mendel's laws ? - Answer-linked traits are likely to
be inherited together. this is not consistent with mendel's law of independent
assortment.
,What is an effect that results when two genes are located side by side on the same
chromosome ? - Answer-Punnett squares can give incorrect predictions of inheritance.
What statement is true ? - Answer-a diploid organism most often has two alleles for a
trait.
What is epistasis ? - Answer-traits where one gene interferes with the effect of another
What is an example of an environmental effect on phenotype ? - Answer-the gender of
sea turtles being affected by the temperature
How many alleles are typically found for mitochondrial genes ? - Answer-1
Which of these are genes that have more than two alleles ? - Answer-the c gene for
melanin production in rabbit coats
Multiple alleles for a gene make populations more diverse .
What are the benefits of this ? Select all that apply . - Answer-it makes it more likely that
a population will survive environmental changes .
if a population encounters a new disease , some of the individuals may be immune to it .
Which of the following statements about polygenic inheritance are true ?
Select all that apply . - Answer-Each gene only contributes a small part to the
phenotype .
When a high number of genes is involved , the number of possible phenotypes is also
high .
What effects can epistasis have on polygenic inheritance ? Select all that apply . -
Answer-a gene can modify the effect of another gene
a gene can mask the effect of another gene
genes can combine to produce entirely new traits
A lab technician observes that the red blood cells in a blood sample display
codominance . What alleles does the person who provided the blood sample have ? -
Answer-iA and iB
A lab technician observes that the red blood cells in a blood sample have surface
antigen B . What alleles does the person who provided the blood sample have ? -
Answer-iBiB or iBi
What are characteristics of polygenic traits ?
Select all that apply . - Answer-on a histogram , traits distribute on a bell-shaped curve
traits are continuous across a range
Which factor determines if someone has brown eyes or green eyes ? - Answer-several
genes acting together
, A few genes are responsible for melanin pigmentation in human skin . Each gene has
one allele that codes for melanin production and one allele that does not .
Which of the following are true ? Select all that apply . - Answer-the combination of
alleles determines how pigmented the skin will be
each allele only contributes a small amount to the phenotype
How can epistatic interactions affect the number of phenotypes that can appear ?
Select all that apply . - Answer-Epistasis can mask genes and prevent them from
affecting the phenotypes .
Epistasis can create new phenotypes .
Epistasis can modify existing phenotypes .
What is the difference between blood types in the ABO blood type system ? - Answer-
antigens on red blood cells
Two people have the genotype IAIB . Of the following options , what possible genotypes
could their children have ? - Answer-iBiB
iAiA
iAiB
A person has blood type B .
What combination of alleles could she have to give her this blood type ?
Select all that apply . - Answer-iBi
iBiB
Two parents both have homozygous genotypes . One parent has blood type A and the
other has blood type B . What genotype can be expected in all of their children ? -
Answer-AB
Blood type is an example of which of the following ?
Select all that apply . - Answer-a situation in which a gene has three or more alleles
a situation in which more than one allele for a trait is dominant
A father is color blind , and a mother is homozygous dominant for normal vision . What
is the probability that one of their offspring will be color blind ? - Answer-0%
Why are males more likely than females to have an X-linked disorder ? - Answer-males
have only one x chromosome ; thus , if a recessive allele is inherited, it is always
expressed .
Which of these describe an inheritance pattern of autosomal genetic disorders ? Select
all that apply . - Answer-for an autosomal dominant disorder to be expressed , just one
copy of the abnormal allele must be inherited .
for an autosomal recessive disorder to be expressed , two copies of the abnormal allele
must be inherited .
