1.
In a Mendelian monohybrid cross, which generation is always completely homozygous?
Correct Answer
D. P generation
Explanation
In a Mendelian monohybrid cross, the P generation is always completely homozygous. This is because the P generation consists of the parental individuals that are crossed to produce the first filial generation (F1). The parental individuals in the P generation are homozygous for the traits being studied, meaning they have two identical alleles for that trait. The F1 generation, on the other hand, is heterozygous as it results from the crossing of two different homozygous individuals. Therefore, the P generation is always completely homozygous in a Mendelian monohybrid cross.
2.
If a pea plant shows a recessive phenotype,
Correct Answer
D. It can be only tt.
Explanation
If a pea plant shows a recessive phenotype, it means that it does not exhibit the dominant trait. In this case, the only possible genotype for the plant to display the recessive phenotype is tt. This is because the recessive trait is represented by a lowercase letter, and two lowercase letters (tt) are needed for the trait to be expressed in the phenotype.
3.
Mendel used statistical methods in the interpretation of his results.
Correct Answer
A. True
Explanation
Mendel used statistical methods in the interpretation of his results. This means that he relied on mathematical analysis and calculations to make sense of the data he collected during his experiments. By using statistical methods, Mendel was able to determine patterns, probabilities, and relationships between different traits in his experiments with pea plants. This approach allowed him to establish the fundamental principles of inheritance and lay the foundation for the field of genetics.
4.
Mendel's work was widely accepted and praised when he reported his results.
Correct Answer
B. Fasle
Explanation
Mendel's work was not widely accepted and praised when he reported his results. In fact, his work on genetics was largely ignored and not recognized until several years after his death. It was only in the early 20th century that his work was rediscovered and gained widespread recognition for its significance in the field of genetics.
5.
The F1 offspring of a monohybrid cross will be intermediate in phenotype between the phenotypes of the parents.
Correct Answer
B. False
Explanation
The F1 offspring of a monohybrid cross will not be intermediate in phenotype between the phenotypes of the parents. In fact, the F1 offspring will exhibit the dominant phenotype of one of the parents, as the dominant allele masks the expression of the recessive allele. Therefore, the F1 offspring will not be a blend of the two parental phenotypes, but rather resemble one of the parents more closely.
6.
The ratio Mendel obtained from his monohybrid cross was approximately 9:3:3:1.
Correct Answer
B. False
Explanation
Mendel did not obtain a ratio of 9:3:3:1 from his monohybrid cross. This ratio is actually the expected phenotypic ratio resulting from a dihybrid cross, where two traits are being studied simultaneously. In a monohybrid cross, which focuses on one trait, the expected phenotypic ratio is 3:1. Therefore, the given statement is false.
7.
The phenotype is the physical appearance of an individual.
Correct Answer
A. True
Explanation
The phenotype refers to the observable characteristics or physical traits of an individual, such as their height, eye color, or hair type. It is determined by the interaction of an individual's genotype (their genetic makeup) with environmental factors. Therefore, the given statement that the phenotype is the physical appearance of an individual is correct.
8.
Each gamete carries one factor, now called an allele, for each inherited trait.
Correct Answer
A. True
Explanation
This statement is true because each gamete, which is a reproductive cell, carries one allele for each inherited trait. Alleles are different forms of a gene that determine specific traits. During fertilization, when gametes combine, the resulting offspring will inherit one allele from each parent for each trait. This is the basis of Mendelian genetics, where the inheritance of traits is determined by the combination of alleles from both parents.
9.
An individual with the genotype Tt will have the dominant phenotype.
Correct Answer
A. True
Explanation
An individual with the genotype Tt will have the dominant phenotype because the dominant allele (T) masks the effects of the recessive allele (t), resulting in the expression of the dominant trait. In this case, since the individual has one dominant allele (T) and one recessive allele (t), the dominant allele will be expressed, leading to the dominant phenotype.
10.
Mendel's law of independent assortment says that members of one pair of factors segregate independently of members of another pair of factors.
Correct Answer
A. True
Explanation
Mendel's law of independent assortment states that the inheritance of one trait is not dependent on the inheritance of another trait. This means that the genes for different traits segregate independently during the formation of gametes. In other words, the alleles for one gene separate and assort into gametes randomly and independently of the alleles for other genes. This principle is a fundamental concept in genetics and has been supported by numerous experiments and observations. Therefore, the given answer, "True," is correct.