Class 10 Science: Heredity — Practice Questions with Answers

In a Mendelian cross, tall pea plants with violet flowers were bred with short pea plants with white flowers. All offspring produced had violet flowers, but approximately half were short. What is the most likely genetic makeup of the tall, violet-flowered parent plant?

1. TTWW
2. TTww
3. TtWW
4. TtWw

If pea plants with round and green seeds (genotype RRyy) are crossed with pea plants having wrinkled and yellow seeds (genotype rrYY), what will be the characteristics of the seeds developed by the plants of the F₁ generation?

1. 50% round and green
2. 75% wrinkled and green
3. 100% round and yellow
4. 75% wrinkled and yellow

This question consists of two statements: Assertion (A) and Reason (R). Select the correct answer from the codes (A), (B), (C), and (D) given below. Assertion (A): A mango seed will germinate to form a mango tree. Reason (R): Heredity determines the process by which traits and characteristics are reliably inherited from parents to offspring.

1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.

A tall pea plant with round seeds (TTRR) is crossed with a short pea plant with wrinkled seeds (ttrr). What is the expected outcome for the F₁ generation?

1. 25% tall with round seeds
2. 50% tall with wrinkled seeds
3. 75% tall with round seeds
4. 100% tall with round seeds

When a pure-tall pea plant is crossed with a pure-dwarf pea plant, what will be the respective percentages of tall pea plants in the F₁ and F₂ generations?

1. (100% ; 25%)
2. (100% ; 50%)
3. (100% ; 75%)
4. (100% ; 100%)

Consider the following statements and identify the correct ones: (i) The sex of a child is determined by the genetic inheritance from the mother. (ii) The sex of a child is determined by the genetic inheritance from the father. (iii) The probability of having a male child is greater than that of a female child. (iv) The sex of a child is established at the moment of fertilization when the male and female gametes fuse.

1. (i) and (iii)
2. (ii) and (iv)
3. (iii) and (iv)
4. (i), (iii) and (iv)

In an experiment studying the independent inheritance of two separate traits, seed shape and seed color, what is the expected ratio of the different combinations in the F2 progeny?

1. 1 : 3
2. 1 : 2 : 1
3. 9 : 3 : 3 : 1
4. 9 : 1 : 1 : 3

When two tall pea plants are crossed, the offspring include a few dwarf plants. What must be the gene-combination of the parental plants?

1. Tt and Tt
2. Tt and tt
3. TT and tt
4. TT and Tt

If a cross between two pea plants results in 50% tall and 50% short offspring, what must be the gene combination of the parental pea plants?

1. Tt and Tt
2. TT and Tt
3. Tt and tt
4. TT and tt

In a cross between a pea plant with white flowers (recessive) and one with homozygous violet flowers (VV, dominant), what will be the ratio of violet flowers to white flowers in the F2 progeny?

1. 1 : 1
2. 2 : 1
3. 3 : 1
4. 1 : 3

Identify the appropriate terms for the following two statements respectively: (i) The trait that is expressed in the F1 generation. (ii) The trait that is passed on from one generation to the next.

1. Recessive trait; Dominant trait
2. Dominant trait; Recessive trait
3. Dominant trait; Inherited trait
4. Recessive trait; Inherited trait

Assertion (A): In humans, if gene (B) is for black eyes and gene (b) is for brown eyes, then progeny with the gene combination Bb or bb will have black eyes. Reason (R): Black eye color is a dominant trait.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true and (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. (A) is false but (R) is true.

Assertion (A): Genes inherited from the parents decide the sex of a child. Reason (R): X chromosome in a male child is inherited from his father.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true and (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. (A) is false but (R) is true.
5. Both (A) and (R) are false.

Which of the following statements accurately describes the characteristics of a gene?

1. In individuals of a given species, a specific gene is located on a particular chromosome.
2. A gene is not the information source for making proteins in the cell.
3. Each chromosome has only one gene located all along its length.
4. All the inherited traits in human beings are not controlled by genes.