1.
In humans, pigmented skin is dominant to non-pigmented skin (albinism). What is the genotype of an individual with albinism?
Correct Answer
D. Homozygous recessive
Explanation
An individual with albinism has a genotype of homozygous recessive. This means that both alleles for the pigmentation gene are recessive, resulting in the absence of pigmentation in the skin. The dominant allele for pigmented skin is not present in the genotype of an individual with albinism.
2.
The principle of dominance states that
Correct Answer
C. Some alleles are dominant and others are recessive.
Explanation
The principle of dominance states that some alleles are dominant and others are recessive. This means that in a pair of alleles for a particular trait, one allele may exert its effect over the other allele, which is considered recessive. The dominant allele determines the phenotype or physical expression of the trait, while the recessive allele remains hidden unless both alleles are recessive. This principle helps explain the inheritance patterns observed in traits and the variations in phenotypes within a population.
3.
Organisms that have two identical alleles for a particular trait are said to be
Correct Answer
B. Homozygous.
Explanation
Organisms that have two identical alleles for a particular trait are said to be homozygous. This means that both alleles present in the organism are the same, whether they are both dominant or both recessive. This is in contrast to heterozygous organisms, which have two different alleles for a particular trait. Hybrid refers to the offspring of two different species or varieties, and dominant refers to the allele that is expressed in the phenotype.
4.
If a pea plant has a recessive allele for green peas, it will produce
Correct Answer
C. Green peas if it does not also have a dominant allele for yellow peas.
Explanation
If a pea plant has a recessive allele for green peas, it will produce green peas if it does not also have a dominant allele for yellow peas. This means that the presence of a dominant allele for yellow peas will override the recessive allele for green peas, resulting in the production of yellow peas instead. However, if the plant does not have a dominant allele for yellow peas, the recessive allele for green peas will be expressed, leading to the production of green peas.
5.
Genotype is the
Correct Answer
B. Genetic make-up of the trait.
Explanation
The correct answer is "genetic make-up of the trait." This means that genotype refers to the specific genes an individual has for a particular trait. It is not related to the physical appearance of the trait, which is known as phenotype. Therefore, the correct answer is that genotype represents the genetic make-up of the trait.
6.
Phenotype is the
Correct Answer
A. pHysical appearance of the trait.
Explanation
The correct answer is "physical appearance of the trait" because phenotype refers to the observable characteristics or traits of an organism. It is determined by the interaction of an organism's genetic makeup (genotype) and environmental factors. The physical appearance of a trait is a direct result of the expression of the genes in an organism's genotype.
7.
If a tall plant (T) is dominant to a short plant (t), what would the genotype be for tall plants?
Correct Answer
D. TT and Tt
Explanation
The genotype for tall plants can be either TT or Tt. This is because the tall plant trait is dominant, so even if an individual has one dominant allele (T) and one recessive allele (t), they will still exhibit the tall plant phenotype. Therefore, both homozygous dominant (TT) and heterozygous (Tt) genotypes will result in tall plants.
8.
If a tall plant (T) is dominant to a short plant (t), what would the plant's phenotype be if it was Tt?
Correct Answer
A. Tall height
Explanation
If a tall plant (T) is dominant to a short plant (t), the plant's phenotype would be tall height if it was Tt. This is because the dominant trait (T) will be expressed in the presence of at least one dominant allele, even if it is paired with a recessive allele (t). Therefore, the plant will exhibit the tall height characteristic.