Chapter Exam

Chapter 8: Heredity and Evolution — Online MCQ Test

Q: Genes are located on:

Answer: B. chromosomes — Genes are segments of DNA present on chromosomes inside the cell nucleus.

Q: A trait that is expressed in the presence of its contrasting trait is called:

Answer: C. dominant trait — A dominant trait shows its effect even when only one copy of the gene is present.

Q: In Mendel's pea plant experiments, which trait was dominant for plant height?

Answer: B. Tallness — Mendel found that tallness is dominant over dwarfness in pea plants.

Q: If a pure tall pea plant is crossed with a pure dwarf pea plant, the F1 generation will be:

Answer: A. all tall — Tallness is dominant, so all F1 plants with genotype Tt will appear tall.

Q: In a monohybrid cross between two heterozygous tall pea plants, the phenotypic ratio in F2 generation is:

Answer: B. 3 tall : 1 dwarf — A Tt x Tt cross gives TT, Tt, Tt, and tt, producing a 3 tall : 1 dwarf phenotypic ratio.

Q: In a dihybrid cross between two heterozygous pea plants for round/yellow seeds, the F2 phenotypic ratio is:

Answer: C. 9 : 3 : 3 : 1 — A dihybrid cross shows independent inheritance of two pairs of traits, giving a 9 : 3 : 3 : 1 ratio in F2.

Q: A pea plant with genotype RrYy is crossed with rryy. What phenotypic ratio is expected in the offspring?

Answer: D. 1 : 1 : 1 : 1 — The RrYy parent forms four types of gametes in equal numbers, and the rryy parent forms only ry gametes, giving four phenotypes equally.

Q: In pea plants, tallness is dominant over dwarfness. If two heterozygous tall plants are crossed, what fraction of the tall offspring will be homozygous tall?

Answer: B. 1/3 — Tt x Tt gives 1 TT, 2 Tt, and 1 tt. Among the tall offspring, 1 out of 3 is homozygous tall.

SCIENCE · Grade 10 · CBSE(NCERT)

Practice Chapter 8: Heredity and Evolution with a free chapter-wise online MCQ test for CBSE(NCERT) Grade 10 SCIENCE. This chapter covers: Mendel Inheritance Traits Genes Chromosomes Dominant Recessive Sex determination Variation Evolution Natural selection Speciation. AI-generated questions from basic to board-exam level, with instant results and explanations.

Questions

20m

Time Limit

Attempts Left

10 random questions from this chapter (mixed difficulty)
Questions you've seen before won't repeat until the pool resets
You have 20 minutes — exam auto-submits when time is up
Maximum 3 attempts per chapter
Results and explanations shown immediately after submission

New here? Register free — includes 3 free chapter exams.

Chapter 8: Heredity and Evolution — Important Questions & Answers (FAQ)

Frequently asked questions from CBSE(NCERT) Grade 10 SCIENCE — Chapter 8: Heredity and Evolution, with answers and explanations. These are sample questions; the exam has its own separate question set.

Heredity refers to the:

A. transfer of characters from parents to offspring ✓
B. change in body size due to exercise
C. formation of fossils in rocks
D. movement of organisms from one place to another

Answer: A. transfer of characters from parents to offspring
Heredity is the transmission of traits from one generation to the next through genetic material.

Genes are located on:

A. ribosomes
B. chromosomes ✓
C. cell wall
D. vacuoles

Answer: B. chromosomes
Genes are segments of DNA present on chromosomes inside the cell nucleus.

A trait that is expressed in the presence of its contrasting trait is called:

A. recessive trait
B. acquired trait
C. dominant trait ✓
D. invisible trait

Answer: C. dominant trait
A dominant trait shows its effect even when only one copy of the gene is present.

In Mendel's pea plant experiments, which trait was dominant for plant height?

A. Dwarfness
B. Tallness ✓
C. Medium height
D. No height

Answer: B. Tallness
Mendel found that tallness is dominant over dwarfness in pea plants.

If a pure tall pea plant is crossed with a pure dwarf pea plant, the F1 generation will be:

A. all tall ✓
B. all dwarf
C. half tall and half dwarf
D. one-fourth dwarf

Answer: A. all tall
Tallness is dominant, so all F1 plants with genotype Tt will appear tall.

In a monohybrid cross between two heterozygous tall pea plants, the phenotypic ratio in F2 generation is:

A. 1 tall : 1 dwarf
B. 3 tall : 1 dwarf ✓
C. 1 tall : 3 dwarf
D. 2 tall : 2 dwarf

Answer: B. 3 tall : 1 dwarf
A Tt x Tt cross gives TT, Tt, Tt, and tt, producing a 3 tall : 1 dwarf phenotypic ratio.

In a dihybrid cross between two heterozygous pea plants for round/yellow seeds, the F2 phenotypic ratio is:

A. 3 : 1
B. 1 : 2 : 1
C. 9 : 3 : 3 : 1 ✓
D. 1 : 1 : 1 : 1

Answer: C. 9 : 3 : 3 : 1
A dihybrid cross shows independent inheritance of two pairs of traits, giving a 9 : 3 : 3 : 1 ratio in F2.

A pea plant with genotype RrYy is crossed with rryy. What phenotypic ratio is expected in the offspring?

A. 9 : 3 : 3 : 1
B. 3 : 1
C. 1 : 1
D. 1 : 1 : 1 : 1 ✓

Answer: D. 1 : 1 : 1 : 1
The RrYy parent forms four types of gametes in equal numbers, and the rryy parent forms only ry gametes, giving four phenotypes equally.

Which statement about evolution is most accurate according to NCERT?

A. Evolution always produces organisms that are superior to older organisms
B. Evolution is a ladder in which humans are the final goal
C. Evolution produces organisms adapted to their environments, not necessarily more advanced ✓
D. Evolution stops when complex organisms appear

Answer: C. Evolution produces organisms adapted to their environments, not necessarily more advanced
Evolution is not a ladder of progress; it results in organisms becoming better suited to particular environments.

In pea plants, tallness is dominant over dwarfness. If two heterozygous tall plants are crossed, what fraction of the tall offspring will be homozygous tall?