Question 1

If all of Mendel's monohybrid crosses had involved traits that function by incomplete dominance, would his results have supported blending inheritance?

Accepted Answer

The answer of If all of Mendel's monohybrid crosses had...

Question 2

A, B, and O blood type in humans is controlled by a single gene with three alleles: I^A, I^B and i. Imagine a fourth allele for blood type, I^C. If it is codominant with I^A and I^B, and dominant to i, how many possible blood type phenotypes are there?

Accepted Answer

With the addition of a fourth allele (I^C) that is codominant with I^A and I^B, and dominant over i, the possible phenotypes would be: A, B, C, AB, AC, BC, and O, making a total of seven possible phenotypes.

Question 3

A, B, and O blood type in humans is controlled by a single gene with three alleles: I^A, I^B and i. Type O is the recessive trait. The i allele is recessive to both I^A and I^B. Which of the following could be possible genotypes of the parents of a person with type O blood?

Accepted Answer

For a person to have type O blood (genotype ii), both parents must carry at least one i allele. Option D (I^Ai and I^Bi) allows for the possibility of both parents passing the i allele to the offspring.

Question 4

Sickle-cell anemia is a disease whose phenotype includes not only anemia, but also damage to many different organs. All phenotypes, however, can be traced to a single gene. This is an example of :

Accepted Answer

Pleiotropy occurs when one gene influences multiple, seemingly unrelated phenotypic traits, which is the case with sickle-cell anemia where a single gene mutation affects various organs and causes anemia.

Question 5

The one gene, one phenotype model:

Accepted Answer

The one gene, one phenotype model is overly simplistic because many traits are influenced by multiple genes, a concept known as polygenic inheritance. This means that aspects of phenotypes are often controlled by many genes, making the model not a good representation of the complexity of genetic inheritance.

Question 6

What are the odds of tossing a coin and having it come up heads three times in a row?

Accepted Answer

The probability of a coin landing on heads in a single toss is 1/2. For three independent events (tosses) happening in a row, the probabilities multiply: 1/2 * 1/2 * 1/2 = 1/8, which is not directly listed as a percentage or fraction in the options, but option D correctly represents the probability of each individual event.

Question 7

To determine the probability of two events occurring at the same time,

Accepted Answer

The probability of two independent events occurring at the same time is found by multiplying their individual probabilities.

Question 8

If one in 10 people carries the I^A allele, and one in 20 people carries the I^B allele, what is the probability that one person will have the I^A I^B genotype?

Accepted Answer

The probability of having the I^A allele is 1/10, and the probability of having the I^B allele is 1/20. To find the probability of having both, multiply the two probabilities: (1/10) * (1/20) = 1/200.

Question 9

Match Mendel's results in column 1 with the conclusion he drew from them in column 2.
-When true-breeding P plants of different types are crossed, the offspring do not have a phenotype intermediate between the two parents.

Accepted Answer

Mendel's observation that offspring did not show a blend of the parents' traits led him to conclude that inheritance does not involve blending, but rather that traits are inherited as distinct units.

Question 10

Match Mendel's results in column 1 with the conclusion he drew from them in column 2.
-When true-breeding P plants are crossed, all offspring had the trait of one of the parents.

Accepted Answer

Mendel concluded that alleles come in dominant and recessive forms because when true-breeding P plants were crossed, all offspring exhibited the trait of one parent, indicating dominance.

Question 11

Match Mendel's results in column 1 with the conclusion he drew from them in column 2. -When F₂ plants, all with the heterozygous phenotype, are self-fertilized, the offspring have dominant and recessive traits in a 3:1 ratio.

Accepted Answer

The answer of Match Mendel's results in column 1 with...

Question 12

Match Mendel's results in column 1 with the conclusion he drew from them in column 2.
-When two traits are followed in a dihybrid cross, heterozygotes give offspring with all combinations of phenotypes, in a 9:3:3:1 ratio.

Accepted Answer

Mendel's observation of a 9:3:3:1 phenotypic ratio in dihybrid crosses led him to conclude that different genes assort independently of each other during gamete formation, which is the principle of independent assortment.

Question 13

Why do you think Mendel cross-fertilized plants in the P generation, but self-fertilized in the F₁ generation?

Accepted Answer

The answer of Why do you think Mendel cross-fertilized plants...

Question 14

What might be the current status of genetics if Mendel had never done his experiments with garden peas?

Accepted Answer

The answer of What might be the current status of...

Question 15

Researchers involved in the Human Genome Project are working to determine the genetic causes of many diseases. In some cases, an allele has been identified that is associated with the particular disease, and a test for that allele can be performed. If a person tests positive for that allele, it does not always mean that they will develop the disease. Explain what else might be a factor in whether the person actually develops the disease.

Accepted Answer

The answer of Researchers involved in the Human Genome Project...

Question 16

Consider the following information for a dihybrid cross. The dominant allele F codes for freckles, whereas the recessive allele f codes for no freckles. The dominant allele E codes for long eyelashes, whereas the recessive allele e codes for short eyelashes. Both parents have the genotypes of ee and Ff. Indicate the following: (1) the phenotype of both parents, (2) the possible gametes that each parent can make, (3) all of the possible phenotypes for the offspring, and (4) the phenotypic ratio obtained after the Punnett square is drawn.

Accepted Answer

The answer of Consider the following information for a dihybrid...

Quiz 11: Mendel and His Discoveries

If all of Mendel's monohybrid crosses had involved traits that function by incomplete dominance, would his results have supported blending inheritance?

A, B, and O blood type in humans is controlled by a single gene with three alleles: IA, IB and i. Imagine a fourth allele for blood type, IC. If it is codominant with IA and IB, and dominant to i, how many possible blood type phenotypes are there?

A, B, and O blood type in humans is controlled by a single gene with three alleles: IA, IB and i. Type O is the recessive trait. The i allele is recessive to both IA and IB. Which of the following could be possible genotypes of the parents of a person with type O blood?

Sickle-cell anemia is a disease whose phenotype includes not only anemia, but also damage to many different organs. All phenotypes, however, can be traced to a single gene. This is an example of :

The one gene, one phenotype model:

What are the odds of tossing a coin and having it come up heads three times in a row?

To determine the probability of two events occurring at the same time,

If one in 10 people carries the IA allele, and one in 20 people carries the IB allele, what is the probability that one person will have the IA IB genotype?

Match Mendel's results in column 1 with the conclusion he drew from them in column 2. -When true-breeding P plants of different types are crossed, the offspring do not have a phenotype intermediate between the two parents.

Match Mendel's results in column 1 with the conclusion he drew from them in column 2. -When true-breeding P plants are crossed, all offspring had the trait of one of the parents.

Match Mendel's results in column 1 with the conclusion he drew from them in column 2. -When F2 plants, all with the heterozygous phenotype, are self-fertilized, the offspring have dominant and recessive traits in a 3:1 ratio.

Match Mendel's results in column 1 with the conclusion he drew from them in column 2. -When two traits are followed in a dihybrid cross, heterozygotes give offspring with all combinations of phenotypes, in a 9:3:3:1 ratio.

Why do you think Mendel cross-fertilized plants in the P generation, but self-fertilized in the F1 generation?