Question 1

Various forms of the same gene are called

Accepted Answer

Alleles are different forms of the same gene that are located at the same position on homologous chromosomes. Genotypes are the specific combination of alleles an individual has. Somatic refers to non-reproductive cells. Recessive refers to a type of allele that is only expressed if paired with another recessive allele. Phenotypes are the observable, physical traits produced by the genotype.

Question 2

If tall ( D ) is dominant to dwarf ( d ), and two homozygous varieties DD and dd are crossed, then what kind of progeny will be produced?

Accepted Answer

Since tall (D) is dominant to dwarf (d), the homozygous dominant (DD) individual will always produce tall progeny when crossed with a homozygous recessive (dd) individual. Therefore, all the progeny will be heterozygous (Dd) and express the tall phenotype since it is dominant.

Question 3

If a homozygous dominant long-haired dog is crossed with a homozygous recessive short-haired dog, what will be the phenotype of the offspring?

Accepted Answer

The answer of If a homozygous dominant long-haired dog is...

Question 4

What was the big piece of the puzzle that was missing from Darwin's theory of evolution in his day?

Accepted Answer

The answer of What was the big piece of the...

Question 5

In cats, short hair ( L ) is dominant to long hair ( l ); if a short-haired cat of unknown genotype is crossed with a long-haired animal, and they produce one long-haired and one short-haired kittens, this would indicate that

Accepted Answer

If the short-haired cat was pure-breeding (LL genotype), then all of its offspring would also be short-haired. Therefore, the fact that one long-haired kitten was produced indicates that the short-haired cat was not pure-breeding and must have been heterozygous (Ll genotype). The long-haired cat's genotype cannot be determined from this limited information.

Question 6

If all offspring of a cross have the same heterozygous genotype, the parents of the cross would most likely be

Accepted Answer

The answer of If all offspring of a cross have...

Question 7

Which of the following was the dominant theory of inheritance before Mendel?

Accepted Answer

The dominant theory of inheritance before Mendel was the theory of blending of traits. This theory proposed that parental traits would blend together in the offspring, resulting in a loss of variation over time. However, Mendel's experiments with pea plants demonstrated that traits were instead inherited in discrete units or "alleles," which could be passed on and expressed independently in future generations.

Question 8

A(n) ____ is an offspring of a cross between two individuals that breed true for different forms of a trait.

Accepted Answer

A hybrid is the offspring of two individuals that breed true for different forms of a trait. They have a combination of alleles from both parents, resulting in varying phenotypes. A homozygote refers to an individual possessing two identical alleles for a particular gene, while recessive and dominant refer to the expression of traits in relation to each other. Phenotype refers to the physical expression of a characteristic, while genotype refers to the genetic makeup of an individual. None of these terms specifically refer to the offspring of a cross between individuals that breed true for different forms of a trait, making choice C the best option.

Question 9

What best explains why some organisms 'breed true" for certain traits?

Accepted Answer

Breeding true means that the offspring have the same traits as the parents, which is only possible if the organisms have identical alleles for those traits.

Question 10

Gene A occurs on chromosome #5; gene B occurs on chromosome #21. Therefore, these two portions of the chromosome CANNOT be

Accepted Answer

The answer of Gene A occurs on chromosome #5; gene...

Question 11

If R is dominant to r , the offspring of the cross of RR with rr will

Accepted Answer

If R is dominant to r, the phenotype of RR and Rr individuals will be the same, because the dominant allele will mask the recessive allele. Therefore, the offspring of the cross between RR and rr individuals will all be heterozygous Rr, but they will have the same phenotype as the RR parents, because the dominant allele will be expressed.

Question 12

Which of the following was Mendel's experimental organism?

Accepted Answer

Mendel's experimental organism was pea plants. He conducted his experiments on pea plants to study the patterns of inheritance of traits from one generation to the next.

Question 13

Which of the following was unknown to Mendel?

Accepted Answer

The answer of Which of the following was unknown to...

Question 14

If red coat is homozygous dominant in horses and white coat is homozygous recessive, in a cross between a homozygous dominant red-coated horse and a white-coated horse, what would the result be in the offspring?

Accepted Answer

The answer of If red coat is homozygous dominant in...

Question 15

Observable traits are known in genetics as

Accepted Answer

Observable traits are referred to as phenotypes in genetics.

Question 16

An allele is ____ if its effect masks that of a ____ allele paired with it.

Accepted Answer

An allele is dominant if its effect masks that of a recessive allele paired with it. This is a fundamental principle of Mendelian genetics, where dominant alleles express their traits over recessive ones when both are present.

Question 17

Regarding the dominant theory of inheritance before Mendel's theory, which of the following is the closest analogy to "genes"?

Accepted Answer

The answer of Regarding the dominant theory of inheritance before...

Question 18

When two alleles of the same gene are different, the individual carrying those alleles is said to be

Accepted Answer

When an individual has two different alleles of the same gene, they are said to be heterozygous. This means that the two alleles are different from one another, and the individual may inherit different traits or expressions of the gene depending on which allele is dominant or recessive.

Question 19

When two alleles of the same gene are identical, the individual carrying those alleles is said to be

Accepted Answer

When the two alleles of a gene are identical, the individual is said to be homozygous for that gene. Homozygous individuals can have either two dominant alleles (homozygous dominant) or two recessive alleles (homozygous recessive).

Question 20

Which of the following determines an observable trait?

Accepted Answer

The answer of Which of the following determines an observable...

Quiz 9: Patterns of Inheritance