Question 1

In horses,black coat (B) is dominant over brown coat (b) ,and being a trotter (T) is dominant over being a pacer (t) .A black horse who is a pacer is crossed with a brown horse who is a trotter.The offspring is a brown pacer.What is the genotype of the brown trotter parent?

Accepted Answer

A)   BBTT
B)   BbTt
C)   Bbtt
D)   bbTt
E)   bbttF) B) and E)
G) None of the above

Question 2

To try and discover if the environment has an effect on a particular characteristic scientists often examine

Accepted Answer

A)   Siblings that share only one parent and were separated at birth.
B)   Dizygotic human twins that were separated at birth.
C)   Monozygotic human twins that were separated at birth.
D)   Siblings that share both parents and were separated at birth.
E)   Unrelated children who have been adopted by the same family and grown up together.F) B) and D)
G) C) and D)

Question 3

In guinea pigs,B = black,b = brown,S = short hair,s = long hair.Two heterozygous individuals reproduce.The expected results are

Accepted Answer

A)   9 black long hair, 3 black short hair, 3 brown long hair, 1 brown short hair.
B)   9 black short hair, 6 black long hair, 3 brown long hair, 1 black short hair.
C)   9 black short hair, 3 black long hair, 3 brown short hair, 1 brown long hair.
D)   9 brown short hair, 3 black long hair, 3 brown long hair, 1 black short hair.
E)   1 black short hair, 1 black long hair, 1 brown short hair, 1 brown long hair.F) A) and B)
G) A) and C)

Question 4

Computer simulations are sometimes used to demonstrate the outcome of monohybrid fruit fly crosses,where a student can run generation after generation of fruit flies with 100 offspring produced each generation,half male and half female,and a 3-to-1 phenotype ratio (or 75 to 25) in the F1 generation.Compared to real genetics results,which of the following is NOT true?

Accepted Answer

A)   Rarely would exactly 100 fly offspring be produced or survive.
B)   An exact balance between males and females would be rare.
C)   A precise 3-to-1 ratio would be uncommon.
D)   It is usually possible to have exactly 100 offspring, half male and half female, and a 3-to-1 phenotypic outcome in real life.
E)   Ratios and outcomes will not be exact but will be very close to the expected numbers.F) B) and E)
G) B) and D)

Question 5

If an albino (recessive) woman is married to a man with normal coloring and they have an albino child,what was the genotype of the man?

Accepted Answer

A)   homozygous dominant
B)   heterozygous
C)   homozygous recessive
D)   incomplete dominance
E)   heterozygous dominantF) A) and E)
G) B) and E)

Question 6

If pairs of factors separate independently of other pairs of factors,you are dealing with the

Accepted Answer

A)   law of segregation.
B)   law of independent assortment.
C)   law of dominance.
D)   multiple alleles.
E)   codominance.F) A) and E)
G) B) and D)

Question 7

In humans,widow's peak (W) is dominant over straight hairline (w) .If a heterozygous male marries a female with a straight hairline,what percent of their children can be expected to have widow's peak?

Accepted Answer

A)   0%
B)   25%
C)   50%
D)   100%
E)   can't be determinedF) C) and D)
G) A) and B)

Question 8

In which kind of cross would you expect to find a ratio of 9:3:3:1 among the F2 offspring?

Accepted Answer

A)   monohybrid cross
B)   dihybrid cross
C)   test cross
D)   homozygous recessive x homozygous dominant
E)   homozygous dominant x heterozygousF) A) and E)
G) A) and B)

Question 9

The _____ indicates the gene combination of an individual.

Accepted Answer

A)   phenotype
B)   loci
C)   genotype
D)   dominance
E)   homozygousF) A) and B)
G) C) and D)

Question 10

Which of the following is an autosomal dominant disorder?

Accepted Answer

A)   Marfan syndrome
B)   Tay-Sachs
C)   Sickle cell disease
D)   Cystic fibrosis (CF) 
E)   Phenylketonuria (PKU) F) None of the above
G) All of the above

Question 11

The four o'clock flower is an example of incomplete dominance: R = red,r = white,and Rr = pink.If two hybrids are crossed,what are the chances that an offspring will have pink flowers?

Accepted Answer

A)   0%
B)   25%
C)   50%
D)   75%
E)   100%F) B) and D)
G) All of the above

Question 12

In guinea pigs,B = black,b = brown,S = short hair,s = long hair.A heterozygous black,shorthaired animal reproduces with a brown,longhaired animal.What is the expected phenotypic ratio of the offspring?

Accepted Answer

A)   1 black short hair, 1 black long hair, 1 brown short hair, 1 brown long hair
B)   3 black short hair, 1 brown long hair, 3 black long hair, 1 brown short hair
C)   9 black short hair, 3 black long hair, 3 brown long hair, 1 brown short hair
D)   9 black short hair, 3 black long hair, 3 brown short hair, 1 brown long hair
E)   9 black short hair, 6 black long hair, 3 brown long hair, 1 brown short hair.F) B) and C)
G) C) and D)

Question 13

Since each child of two heterozygous parents has a 1/4 chance of receiving a recessive trait from each parent,

Accepted Answer

A)   if the first child is phenotypically recessive, then the next child must be phenotypically dominant.
B)   if the first child is phenotypically recessive, then the next child has a 3/4 chance of being phenotypically recessive.
C)   if the first child is phenotypically recessive, then the next child has a 1/2 chance of being phenotypically recessive.
D)   if the first child is phenotypically recessive, then the next child has a 1/4 chance of being phenotypically dominant.
E)   no matter what the first child's phenotype, the next child will have a 1/4 chance of being phenotypically recessive.F) A) and D)
G) C) and D)

Question 14

The ability to roll the edges of the tongue upward in a U-shape has been considered to be an inherited ability.The standard assumption is that tongue-rolling is a dominant allele at a single gene locus.Which of the following would cast doubt on this assumption?

Accepted Answer

A)   Behaviors are not inherited, only structures are inherited.
B)   A student who cannot roll his tongue has a mother and father, both of whom can.
C)   A student who can roll his tongue has a mother and father, both of whom cannot.
D)   With very little effort the non-tongue-rollers can learn to also roll their tongues.
E)   A student who can roll his tongue has a mother and father, both of whom cannot roll their tongues AND with very little effort the non-tongue-rollers can learn to roll their tongues.F) A) and D)
G) C) and D)

Question 15

Traits that are controlled by several sets or pairs of alleles,such as skin color and height in humans,are the result of what form of inheritance?

Accepted Answer

A)   polygenic
B)   incomplete dominance
C)   multiple allele systems
D)   simple Mendelian inheritance
E)   codominanceF) B) and D)
G) C) and D)

Question 16

In peas,yellow is dominant over green in seeds.With which of these is it best to cross a yellow-seeded pea plant to determine whether it is homozygous or heterozygous?

Accepted Answer

A)   a green-seeded plant
B)   a heterozygous yellow-seeded plant
C)   a pure yellow-seeded plant
D)   a heterozygous yellow-seeded plant or a pure yellow-seeded plant
E)   There is no way to determine if the plant is pure or hybridF) B) and D)
G) A) and D)

Question 17

Mr.X has been accused by Miss Z of fathering her child.The child's blood type is AB and Miss Z's blood type is A.Mr.X could NOT be the father if his blood type is

Accepted Answer

A)  only A.
B)  only B.
C)  AB.
D)  only O.
E)  either A or O.F) A) and B)
G) A) and C)

Question 18

Which of the following crosses will yield only homozygous recessive offspring?

Accepted Answer

A)   RRYY x RRYY
B)   RRYY x rryy
C)   RrYy x rryy
D)   rryy x rryy
E)   RrYy x RrYyF) None of the above
G) B) and C)

Question 19

Mendel's law of segregation implies that the two members of an allele pair

Accepted Answer

A)   are distributed to separate gametes.
B)   are distributed to the same gamete.
C)   are assorted dependently.
D)   are segregated pairwise.
E)   must always code for the identical trait or feature.F) B) and D)
G) A) and D)

Question 20

A cross is made between two parents with genotypes AaBB and aabb.If there are 32 offspring,how many of them would be expected to exhibit both dominant characteristics?

Accepted Answer

A)   32
B)   24
C)   16
D)   8
E)   0F) B) and E)
G) D) and E)

Exam 23: Patterns of Gene Inheritance

Which of the following crosses will yield only homozygous recessive offspring?

Correct Answer
verified

To try and discover if the environment has an effect on a particular characteristic scientists often examine

Correct Answer
verified

In guinea pigs,B = black,b = brown,S = short hair,s = long hair.A heterozygous black,shorthaired animal reproduces with a brown,longhaired animal.What is the expected phenotypic ratio of the offspring?

Correct Answer
verified

The four o'clock flower is an example of incomplete dominance: R = red,r = white,and Rr = pink.If two hybrids are crossed,what are the chances that an offspring will have pink flowers?

Correct Answer
verified

If pairs of factors separate independently of other pairs of factors,you are dealing with the

Correct Answer
verified

The ability to roll the edges of the tongue upward in a U-shape has been considered to be an inherited ability.The standard assumption is that tongue-rolling is a dominant allele at a single gene locus.Which of the following would cast doubt on this assumption?

Correct Answer
verified

In guinea pigs,B = black,b = brown,S = short hair,s = long hair.Two heterozygous individuals reproduce.The expected results are

Correct Answer
verified

Traits that are controlled by several sets or pairs of alleles,such as skin color and height in humans,are the result of what form of inheritance?

Correct Answer
verified

Correct Answer
verified

Mendel's law of segregation implies that the two members of an allele pair

Correct Answer
verified

In which kind of cross would you expect to find a ratio of 9:3:3:1 among the F₂ offspring?

Correct Answer
verified

The _____ indicates the gene combination of an individual.

Correct Answer
verified

In humans,widow's peak (W) is dominant over straight hairline (w) .If a heterozygous male marries a female with a straight hairline,what percent of their children can be expected to have widow's peak?

Correct Answer
verified

In peas,yellow is dominant over green in seeds.With which of these is it best to cross a yellow-seeded pea plant to determine whether it is homozygous or heterozygous?

Correct Answer
verified

Mr.X has been accused by Miss Z of fathering her child.The child's blood type is AB and Miss Z's blood type is A.Mr.X could NOT be the father if his blood type is

Correct Answer
verified

Since each child of two heterozygous parents has a 1/4 chance of receiving a recessive trait from each parent,

Correct Answer
verified

If an albino (recessive) woman is married to a man with normal coloring and they have an albino child,what was the genotype of the man?

Correct Answer
verified

In horses,black coat (B) is dominant over brown coat (b) ,and being a trotter (T) is dominant over being a pacer (t) .A black horse who is a pacer is crossed with a brown horse who is a trotter.The offspring is a brown pacer.What is the genotype of the brown trotter parent?

Correct Answer
verified

Which of the following is an autosomal dominant disorder?

Correct Answer
verified

A cross is made between two parents with genotypes AaBB and aabb.If there are 32 offspring,how many of them would be expected to exhibit both dominant characteristics?

Correct Answer
verified

Exam 23: Patterns of Gene Inheritance

Which of the following crosses will yield only homozygous recessive offspring?

Correct AnswerverifiedShow Answer

To try and discover if the environment has an effect on a particular characteristic scientists often examine

Correct AnswerverifiedShow Answer

In guinea pigs,B = black,b = brown,S = short hair,s = long hair.A heterozygous black,shorthaired animal reproduces with a brown,longhaired animal.What is the expected phenotypic ratio of the offspring?

Correct AnswerverifiedShow Answer

The four o'clock flower is an example of incomplete dominance: R = red,r = white,and Rr = pink.If two hybrids are crossed,what are the chances that an offspring will have pink flowers?

Correct AnswerverifiedShow Answer

If pairs of factors separate independently of other pairs of factors,you are dealing with the

Correct AnswerverifiedShow Answer

The ability to roll the edges of the tongue upward in a U-shape has been considered to be an inherited ability.The standard assumption is that tongue-rolling is a dominant allele at a single gene locus.Which of the following would cast doubt on this assumption?

Correct AnswerverifiedShow Answer

In guinea pigs,B = black,b = brown,S = short hair,s = long hair.Two heterozygous individuals reproduce.The expected results are

Correct AnswerverifiedShow Answer

Traits that are controlled by several sets or pairs of alleles,such as skin color and height in humans,are the result of what form of inheritance?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Mendel's law of segregation implies that the two members of an allele pair

Correct AnswerverifiedShow Answer

In which kind of cross would you expect to find a ratio of 9:3:3:1 among the F2 offspring?

Correct AnswerverifiedShow Answer

The _____ indicates the gene combination of an individual.

Correct AnswerverifiedShow Answer

In humans,widow's peak (W) is dominant over straight hairline (w) .If a heterozygous male marries a female with a straight hairline,what percent of their children can be expected to have widow's peak?

Correct AnswerverifiedShow Answer

In peas,yellow is dominant over green in seeds.With which of these is it best to cross a yellow-seeded pea plant to determine whether it is homozygous or heterozygous?

Correct AnswerverifiedShow Answer

Mr.X has been accused by Miss Z of fathering her child.The child's blood type is AB and Miss Z's blood type is A.Mr.X could NOT be the father if his blood type is

Correct AnswerverifiedShow Answer

Since each child of two heterozygous parents has a 1/4 chance of receiving a recessive trait from each parent,

Correct AnswerverifiedShow Answer

If an albino (recessive) woman is married to a man with normal coloring and they have an albino child,what was the genotype of the man?

Correct AnswerverifiedShow Answer

In horses,black coat (B) is dominant over brown coat (b) ,and being a trotter (T) is dominant over being a pacer (t) .A black horse who is a pacer is crossed with a brown horse who is a trotter.The offspring is a brown pacer.What is the genotype of the brown trotter parent?

Correct AnswerverifiedShow Answer

Which of the following is an autosomal dominant disorder?

Correct AnswerverifiedShow Answer

A cross is made between two parents with genotypes AaBB and aabb.If there are 32 offspring,how many of them would be expected to exhibit both dominant characteristics?

Correct AnswerverifiedShow Answer

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In which kind of cross would you expect to find a ratio of 9:3:3:1 among the F₂ offspring?

Correct Answer
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