How many marks does "Heredity and Evolution" carry in Bihar Board Class 10 Science?

In the Bihar Board papers of 2021–2026, this chapter carried about 2 marks and about 3 questions a year; by marks it ranks 16 in Science.

Which are the most important (VVI) questions of "Heredity and Evolution"?

The 6 questions above are from the board’s real papers, each with the years it was asked; the most-asked come first with their full model answers. All 6 written questions of this chapter, with answers, are in the AskMedha app.

Do the answers follow the board’s marking scheme?

BSEB does not publish a marking scheme. Each answer is written point by point on a structure derived from past papers and checked by a second, independent model; it is never called the board’s official scheme.

Bihar Board Class 10 · Science · Matric exam 2027

Chapter 9: Heredity and Evolution

This chapter’s questions from Bihar Board (BSEB)’s real papers of 2021–2026 — the 6 asked most often, 3 with the full model answer, 3 with how the answer begins — and objective questions with the board’s key.

marks a year (about): 2
questions a year (about): 3
rank in Science: #16

From 6 years of papers, 2021–2026 · full chapter-wise marks

Chapter 9 notes (PDF) →

VVI questions — the ones the board asked most (6)

Q1Short answer2 marksAsked: 2022, 2025
How is DNA the basis of heredity ?
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Model answer · DNA and heredity
1. 1.DNA is located in the nucleus of the cell and is the information source for making proteins in the cell. During sexual reproduction, both parents contribute equally to the DNA of the progeny. Through this DNA copying, genetic information is transferred from one generation to the next.1 mark
2. 2.DNA contains the codes necessary for protein synthesis. A section of DNA that provides information for one protein is called the gene for that protein. Since proteins control the characteristics of an organism, genes control characteristics, or traits, which determine the physical and functional traits of organisms.1 mark
- Write that DNA is located in the nucleus of the cell and that DNA copying transfers information from one generation to the next.
- State that a section of DNA is called the gene for a protein and genes control traits.
Marks split from a structure derived from past papers (checked twice); not Bihar Board’s official scheme
Q2Short answer2 marksAsked: 2025
What is the meaning of biological evolution?
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Model answer · meaning of organic evolution
1. 1.Organic evolution is the slow and gradual process by which complex organisms have originated from simpler organisms.1 mark
2. 2.This process takes place over millions of years and involves continuous changes in the physical structure of organisms.1 mark
- Write the definition starting with 'Organic evolution is the slow and gradual process' and mention 'complex organisms' and 'simpler organisms'.
- State that the process 'takes place over millions of years' and involves 'continuous changes in the physical structure of organisms'.
Marks split from a structure derived from past papers (checked twice); not Bihar Board’s official scheme
Q3Short answer2 marksAsked: 2026
What is called gene pattern or genotype ?
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Model answer · genotype, heredity
1. 1.The genetic constitution of an organism, that is the set of genes present in it, is called genotype. It is also known as gene pattern.1 mark
2. 2.It determines the hereditary traits of an organism. Since this genetic constitution is stored in DNA, it is transferred from one generation to the next, thus deciding the characteristics that appear in the offspring.1 mark
- Begin with 'The genetic constitution of an organism... is called genotype.'
- Mention 'set of genes' while defining genotype.
- State that genotype is stored in DNA and is responsible for hereditary traits passed to the next generation.
Marks split from a structure derived from past papers (checked twice); not Bihar Board’s official scheme
Q4Short answer2 marksAsked: 2026
Define genotype and phenotype.
How the model answer begins
1. Genotype represents the genetic constitution or the combination of genes of an organism. It is the set of genes that an organism inherits from its parents and decides the traits that may be expressed. Thus, the genotype…
The full answer from Medha Ma’am →
Q5Short answer2 marksAsked: 2026
What do you understand by homologous organs ? Give examples.
How the model answer begins
1. Organs which have the same basic structure and origin but perform different functions are called homologous organs. Such a homologous characteristic helps to identify an evolutionary relationship between apparently…
The full answer from Medha Ma’am →
Q6Short answer2 marksAsked: 2025
How is DNA the basis of heredity ?
How the model answer begins
1. DNA is present in the nucleus of the cell and is the information source that is passed from parents to progeny during reproduction, transferring genetic information from one generation to the next. This is how DNA forms…
The full answer from Medha Ma’am →

Objective questions with the board’s key (10)

1. Bihar Board 2026
The number of sex chromosomes in human gametes is
- (A) 1 ✓
- (B) 2
- (C) 3
- (D) 4
Answer: (A)
2. Bihar Board 2026
Which of the following is the pair of sex-chromosomes found in males?
- (A) XX
- (B) XY ✓
- (C) YY
- (D) XO
Answer: (B)
3. Bihar Board 2026
The number of autosomes in humans is
- (A) 22 pairs ✓
- (B) 23 pairs
- (C) 11 pairs
- (D) 24 pairs
Answer: (A)
4. Bihar Board 2025
What is the meaning of atavism?
- (A) Inheritance of parental characteristics in progeny
- (B) No inheritance of parental characteristics in progeny
- (C) Inheritance of ancestral characteristics in progeny, which are not in parents ✓
- (D) All of these
Answer: (C)
5. Bihar Board 2025
The genetic structure of an organism is called
- (A) Phenotype
- (B) Genotype ✓
- (C) Heredity
- (D) Diversity
Answer: (B)
6. Bihar Board 2025
The evolution of organisms by natural selection is called
- (A) Mendelism
- (B) Lamarckism
- (C) Micro-development
- (D) Darwinism ✓
Answer: (D)
7. Bihar Board 2024
The place of origin of human is
- (A) India
- (B) China
- (C) Africa ✓
- (D) America
Answer: (C)
8. Bihar Board 2024
The number of pairs of autosomes in human is
- (A) 24
- (B) 23
- (C) 11
- (D) 22 ✓
Answer: (D)
9. Bihar Board 2023
Which plant did Mendel choose for his experiment ?
- (A) Pea ✓
- (B) Gram
- (C) Wheat
- (D) All of these
Answer: (A)
10. Bihar Board 2023
Who among the following is called the 'Father of Biology' ?
- (A) Lamarck
- (B) Aristotle ✓
- (C) Charles Darwin
- (D) Gregor Johann Mendel
Answer: (B)

Questions parents and students ask

How many marks does "Heredity and Evolution" carry in Bihar Board Class 10 Science?: In the Bihar Board papers of 2021–2026, this chapter carried about 2 marks and about 3 questions a year; by marks it ranks 16 in Science.
Which are the most important (VVI) questions of "Heredity and Evolution"?: The 6 questions above are from the board’s real papers, each with the years it was asked; the most-asked come first with their full model answers. All 6 written questions of this chapter, with answers, are in the AskMedha app.
Do the answers follow the board’s marking scheme?: BSEB does not publish a marking scheme. Each answer is written point by point on a structure derived from past papers and checked by a second, independent model; it is never called the board’s official scheme.

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Every question of every chapter with its model answer, practice questions in the board’s own shapes, 60 minutes of class a day, written answers marked, a test every Sunday and a WhatsApp report to parents.

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