Question 1

Assuming complete dominance, a 3:1 phenotypic ratio is expected from a monohybrid sib or self -cross.

Accepted Answer

A 3:1 phenotypic ratio is expected from a monohybrid sib or self-cross if complete dominance is assumed. This means that the offspring will show a dominant phenotype if they inherit even one copy of the dominant allele. The ratio is expected to be 3:1 because three out of four possible outcomes will result in a dominant phenotype (DD, Dd, and dD), while only one out of four possible outcomes will result in a recessive phenotype (dd).

Question 2

Assume that a Chi -square test provided a probability value of 0.02. Should the null hypothesis be accepted?

Accepted Answer

The answer of Assume that a Chi -square test provided...

Question 3

A gene can have a maximum of two alleles.

Accepted Answer

A gene can have more than two alleles because alleles are variations of a gene, and many genes have multiple variations within a population.

Question 4

Assume that a Chi -square test was conducted to test the goodness of fit to a 9:3:3:1 ratio and a Chi -square value of 10.62 was obtained. Should the null hypothesis be accepted?

Accepted Answer

The answer of Assume that a Chi -square test was...

Question 5

Mendel's Law of Segregation is supported by a 1:1 ratio of offspring when one parent is heterozygous and the other is homozygous recessive.

Accepted Answer

Mendel's Law of Segregation states that alleles segregate independently during gamete formation, resulting in a 1:1 ratio of offspring when a heterozygous parent (Aa) is crossed with a homozygous recessive parent (aa), producing offspring genotypes of Aa and aa.

Question 6

Assume that a Chi -square test was conducted to test the goodness of fit to a 3:1 ratio and that a Chi -square value of 2.62 was obtained. Should the null hypothesis be
accepted? How many degrees of freedom would be associated with this test of significance?

Accepted Answer

The answer of Assume that a Chi -square test was...

Question 7

In a Chi -square test, as the value of the ç2 increases, the likelihood of rejecting the null hypothesis _.

Accepted Answer

The answer of In a Chi -square test, as the...

Question 8

Assume that a cross is made between a heterozygous tall pea plant and a homozygous short pea plant. Fifty offspring are produced in the following frequency:
30 = tall
20 = short
a() What frequency of tall and short plants is expected?
b() To test the goodness of fit between the observed and expected values, provide the needed statement of the null hypothesis.
c() Compute a Chi -square value associated with the appropriate test of significance.
d() How many degrees of freedom are associated with this test of significance?

Accepted Answer

The answer of Assume that a cross is made between...

Question 9

In a Chi -square analysis, what condition causes one to reject (fail to accept) the null hypothesis?

Accepted Answer

The answer of In a Chi -square analysis, what condition...

Question 10

The nonfunctional form of a gene is called a wild -type allele.

Accepted Answer

The wild-type allele is typically the functional form of a gene that is considered the standard or normal version found in nature, whereas nonfunctional or altered versions are referred to as mutant alleles.

Question 11

Mendel's discoveries were well received and understood by his contemporaries.

Accepted Answer

Mendel's discoveries were initially met with little interest or understanding by his contemporaries and it was only years later that his work gained recognition and became influential in the field of genetics.

Question 12

If one is testing a goodness of fit to a 9:3:3:1 ratio, how many degrees of freedom would be associated with the Chi -square analysis?

Accepted Answer

The answer of If one is testing a goodness of...

Question 13

To test Mendel's Law of Segregation, the experimenter needs a minimum of two contrasting forms of a gene.

Accepted Answer

Mendel's Law of Segregation states that individuals have two copies of each gene, and these copies segregate (separate) during gamete formation, with each gamete receiving only one copy. In order to observe this segregation, the experimenter needs at least two versions of the gene, or alleles, that result in distinct traits. These contrasting forms allow the experimenter to track the inheritance pattern and determine whether the law of segregation holds true.

Question 14

In studies of human genetics, usually a single individual brings the condition to the attention of a scientist or physician. When pedigrees are developed to illustrate
transmission of the trait, what term is used to refer to this individual?

Accepted Answer

The answer of In studies of human genetics, usually a...

Question 15

A 1:1 phenotypic ratio is expected from a monohybrid cross involving a heterozygote with a homozygous recessive organism.

Accepted Answer

In a monohybrid cross between a heterozygote (Aa) and a homozygous recessive (aa), the expected phenotypic ratio is 1:1, with half of the offspring displaying the dominant phenotype (Aa) and half displaying the recessive phenotype (aa).

Question 16

In what ways is sample size related to statistical testing?

Accepted Answer

The answer of In what ways is sample size related...

Question 17

Mendel's postulate of independent assortment is supported by a 1:1:1:1 testcross ratio.

Accepted Answer

The 1:1:1:1 testcross ratio is a result of the independent assortment of alleles on different chromosomes, as predicted by Mendel's postulate. Therefore, the statement is true.

Question 18

A 9:3:3:1 phenotypic ratio is expected from a dihybrid cross between a double heterozygote and a fully recessive organism.

Accepted Answer

A 9:3:3:1 phenotypic ratio is expected from a dihybrid cross between two heterozygous organisms, not between a double heterozygote and a fully recessive organism, which would result in a 1:1:1:1 ratio.

Quiz 3: Mendelian Genetics