Question 1

The offspring of a monohybrid testcross would have what possible genotype(s) ?

Accepted Answer

A)   AA and Aa
B)   Aa and aa
C)   AA, Aa, and aa
D)   AA only
E)   aa only

Question 2

In what kind of classic Mendelian 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)   testcross
D)   None of the choices is correct.

Question 3

Some plants fail to produce chlorophyll, and this trait appears to be recessive. Many plants also self-pollinate. If we locate a pea plant that is heterozygous for this trait, self-pollinate it and harvest seeds, what are the likely phenotypes of these seeds when they germinate?

Accepted Answer

A)   All will be green with chlorophyll since that is the dominant trait.
B)   All will be white and lack chlorophyll since this is self-pollinated.
C)   About one-half will be green and one-half white since that is the distribution of the genes in the parents.
D)   About one-fourth will be white and three-fourths green since it is similar to a monohybrid cross between heterozygotes.
E)   About one-fourth will be green and three-fourths white since it is similar to a monohybrid cross between heterozygotes.

Question 4

When crossing a true-breeding red snapdragon flower with a true-breeding white flower of the same species, we secure all pink offspring. This would seem to support the pre-Mendel view that inheritance is a blending of parental traits. However, Mendel and conventional wisdom agree that "blending" of parental traits is not correct and that particles of inheritance are actually involved because

Accepted Answer

A)   in the case of incomplete dominance, only radioactive isotope tracers can follow the actual hereditary particles.
B)   under blending theory, over many generations only the average (or pink flowers)  would remain; there would be no way to get back to pure red and white.
C)   it is possible to cross the pink F-1 generation and secure a predictable proportion of pure red and white flowers again, which is not accounted for under the blending theory.
D)   there is no way to directly prove incomplete dominance is not a case of blending, but we can be sure of genes because of the other cases of dominance, etc., where genes are the only logical explanation.
E)   two of these are true.

Question 5

If a woman is a carrier for the color-blind recessive allele and her husband is normal, what are their chances that a son will be color-blind?

Accepted Answer

A)   None since the father is normal.
B)   50% since the mother is the only carrier.
C)   100% because the mother has the gene.
D)   25% because the mother is a hybrid.
E)   None since he will also be just a carrier.

Question 6

Black and brown guinea pigs are bred. Assuming their color is determined by one gene, and that there is a dominant and a recessive allele, how would you determine which allele is dominant? How could you determine the genotypes of the parents? Explain.

Accepted Answer

Answers may vary.
Situation 1: If both p...

Question 7

What are alleles?

Accepted Answer

A)   genes for different traits, such as hair color or eye color
B)   alternative forms of a gene for a single trait, such as blue eyes or brown eyes
C)   the locations of genes on a chromosome
D)   recessive forms of a kind of characteristic carried by genes
E)   dominant forms of a kind of characteristic carried by genes

Question 8

Which of the following scenarios would not have been used by Mendel during his research?

Accepted Answer

A)   relied on his memory to remember his data
B)   followed the scientific method when designing his experiments
C)   used a statistic analysis to determine if his data was valid
D)   researched multiple generations of pea plants to help derive his conclusions

Question 9

If the probability of event A is 3/4 and the probability of event B is 1/4, then the probability of both A and B occurring at the same time is

Accepted Answer

A)   3/4.
B)   1/4.
C)   1 or absolute certainty.
D)   1/2.
E)   3/16.

Question 10

If individuals exhibiting a dominant phenotype are crossed and produce only offspring with the dominant phenotype, what would be the logical genotype of the parents?

Accepted Answer

A)   both are homozygous recessive
B)   one is heterozygous and one is homozygous dominant
C)   both are homozygous dominant
D)   both are heterozygous
E)   two of the options may be correct

Question 11

When a round fruit plant is crossed with a long fruit plant their offspring are oval. What is the best explanation for this scenario?

Accepted Answer

A)   pleiotropic inheritance
B)   polygenic inheritance
C)   incomplete dominance
D)   X-linked inheritance

Question 12

In a case of incomplete dominance, the phenotypic ratio of the F2 generation is the same as the genotypic ratio.

Accepted Answer

A) True 
 B)False

Question 13

A testcross involves an individual exhibiting the dominant phenotype but an unknown genotype being crossed with an individual that has a(n)  ___________ genotype.

Accepted Answer

A)   homozygous dominant
B)   heterozygous dominant
C)   homozygous recessive
D)   any of the choices

Question 14

Which of the following is not part of Mendel's law of segregation?

Accepted Answer

A)   Each individual has two factors for each trait.
B)   The factors segregate during Meiosis.
C)   Each gamete will contain two factors for a trait.
D)   Fertilization gives the offspring two factors for each trait.

Question 15

Lethal genes (genes that result in the failure to develop a vital organ or metabolic pathway)  are nearly always recessive. Animal breeders who discover a unique trait and selectively breed to increase the occurrence of that trait often encounter a noticeable increase in lethal genes. Why?

Accepted Answer

A)   The lethal recessive gene may be incompletely dominant.
B)   Spreading the gene among offspring of both sexes will increase the likelihood it will be sex-linked and expressed.
C)   The selective-mating of closely related individuals, or inbreeding, increases chances that two recessive genes will "meet" in offspring.
D)   "Pleiotropy" - the gene that is being selected for this trait may have the second effect of being lethal.
E)   "Epistasis" - selection for the desired trait may result in "uncovering" the lethal gene.

Question 16

Which allele combination represents a homozygous dominant individual?

Accepted Answer

A)   AA
B)   Aa
C)   aa
D)   none of these are homozygous dominant individuals

Question 17

If an individual with a dominant phenotype is crossed with an individual with a recessive phenotype, 4 of their 9 offspring show the recessive phenotype. What is the genotype of the first parent?

Accepted Answer

A)   AA
B)   Aa
C)   aa
D)   The answer cannot be determined from this information.

Question 18

The F2 offspring of a classic Mendelian monohybrid cross between homozygous dominant and homozygous recessive parents would produce the genotype(s)

Accepted Answer

A)   AA and Aa.
B)   Aa and aa.
C)   AA, Aa, and aa.
D)   AA only.
E)   Aa only.

Question 19

Which of the following reasons helped make Mendel successful with his genetic experiments?

Accepted Answer

A)   He had a strong background in mathematics.
B)   He was very deliberate and followed the scientific method closely while doing his research.
C)   He kept very detailed records of his research.
D)   He was basing his research off of preexisting research.
E)   All are reasons Mendel was successful with his genetic experiments.

Question 20

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 with real genetics results,

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)   All of the choices are true.

Exam 11: Mendelian Patterns of Inheritance

Which allele combination represents a homozygous dominant individual?

Correct Answer
verified

If individuals exhibiting a dominant phenotype are crossed and produce only offspring with the dominant phenotype, what would be the logical genotype of the parents?

Correct Answer
verified

Which of the following is not part of Mendel's law of segregation?

Correct Answer
verified

Correct Answer
verified

Which of the following scenarios would not have been used by Mendel during his research?

Correct Answer
verified

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

Correct Answer
verified

If the probability of event A is 3/4 and the probability of event B is 1/4, then the probability of both A and B occurring at the same time is

Correct Answer
verified

The F₂ offspring of a classic Mendelian monohybrid cross between homozygous dominant and homozygous recessive parents would produce the genotype(s)

Correct Answer
verified

Some plants fail to produce chlorophyll, and this trait appears to be recessive. Many plants also self-pollinate. If we locate a pea plant that is heterozygous for this trait, self-pollinate it and harvest seeds, what are the likely phenotypes of these seeds when they germinate?

Correct Answer
verified

The offspring of a monohybrid testcross would have what possible genotype(s) ?

Correct Answer
verified

Which of the following reasons helped make Mendel successful with his genetic experiments?

Correct Answer
verified

What are alleles?

Correct Answer
verified

If a woman is a carrier for the color-blind recessive allele and her husband is normal, what are their chances that a son will be color-blind?

Correct Answer
verified

Lethal genes (genes that result in the failure to develop a vital organ or metabolic pathway) are nearly always recessive. Animal breeders who discover a unique trait and selectively breed to increase the occurrence of that trait often encounter a noticeable increase in lethal genes. Why?

Correct Answer
verified

When a round fruit plant is crossed with a long fruit plant their offspring are oval. What is the best explanation for this scenario?

Correct Answer
verified

If an individual with a dominant phenotype is crossed with an individual with a recessive phenotype, 4 of their 9 offspring show the recessive phenotype. What is the genotype of the first parent?

Correct Answer
verified

A testcross involves an individual exhibiting the dominant phenotype but an unknown genotype being crossed with an individual that has a(n) ___________ genotype.

Correct Answer
verified

In a case of incomplete dominance, the phenotypic ratio of the F₂ generation is the same as the genotypic ratio.

Correct Answer
verified

Correct Answer
verified

Black and brown guinea pigs are bred. Assuming their color is determined by one gene, and that there is a dominant and a recessive allele, how would you determine which allele is dominant? How could you determine the genotypes of the parents? Explain.

Correct Answer
verified
Answers may vary.
Situation 1: If both p...
View Answer

Exam 11: Mendelian Patterns of Inheritance

Which allele combination represents a homozygous dominant individual?

Correct AnswerverifiedShow Answer

If individuals exhibiting a dominant phenotype are crossed and produce only offspring with the dominant phenotype, what would be the logical genotype of the parents?

Correct AnswerverifiedShow Answer

Which of the following is not part of Mendel's law of segregation?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following scenarios would not have been used by Mendel during his research?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

If the probability of event A is 3/4 and the probability of event B is 1/4, then the probability of both A and B occurring at the same time is

Correct AnswerverifiedShow Answer

The F2 offspring of a classic Mendelian monohybrid cross between homozygous dominant and homozygous recessive parents would produce the genotype(s)

Correct AnswerverifiedShow Answer

Some plants fail to produce chlorophyll, and this trait appears to be recessive. Many plants also self-pollinate. If we locate a pea plant that is heterozygous for this trait, self-pollinate it and harvest seeds, what are the likely phenotypes of these seeds when they germinate?

Correct AnswerverifiedShow Answer

The offspring of a monohybrid testcross would have what possible genotype(s) ?

Correct AnswerverifiedShow Answer

Which of the following reasons helped make Mendel successful with his genetic experiments?

Correct AnswerverifiedShow Answer

What are alleles?

Correct AnswerverifiedShow Answer

If a woman is a carrier for the color-blind recessive allele and her husband is normal, what are their chances that a son will be color-blind?

Correct AnswerverifiedShow Answer

Lethal genes (genes that result in the failure to develop a vital organ or metabolic pathway) are nearly always recessive. Animal breeders who discover a unique trait and selectively breed to increase the occurrence of that trait often encounter a noticeable increase in lethal genes. Why?

Correct AnswerverifiedShow Answer

When a round fruit plant is crossed with a long fruit plant their offspring are oval. What is the best explanation for this scenario?

Correct AnswerverifiedShow Answer

If an individual with a dominant phenotype is crossed with an individual with a recessive phenotype, 4 of their 9 offspring show the recessive phenotype. What is the genotype of the first parent?

Correct AnswerverifiedShow Answer

A testcross involves an individual exhibiting the dominant phenotype but an unknown genotype being crossed with an individual that has a(n) ___________ genotype.

Correct AnswerverifiedShow Answer

In a case of incomplete dominance, the phenotypic ratio of the F2 generation is the same as the genotypic ratio.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Black and brown guinea pigs are bred. Assuming their color is determined by one gene, and that there is a dominant and a recessive allele, how would you determine which allele is dominant? How could you determine the genotypes of the parents? Explain.

Correct AnswerverifiedAnswers may vary.Situation 1: If both p...View AnswerShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

The F₂ offspring of a classic Mendelian monohybrid cross between homozygous dominant and homozygous recessive parents would produce the genotype(s)

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

In a case of incomplete dominance, the phenotypic ratio of the F₂ generation is the same as the genotypic ratio.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Answers may vary.
Situation 1: If both p...
View Answer