Genetic Variation — Homi Bhabha Class 9 Biology MCQs with Solutions
Free Homi Bhabha Class 9 Biology Genetic Variation MCQs with step-by-step solutions (15 questions). Part of Heredity & Genetics. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Genetic Variation · medium · theory
The differences seen among individuals of the same species are called:
A. clones
B. variations ✓ Correct
C. mutations only
D. traits
Solution: Variations are the differences in characteristics among individuals of a species.
Q2 — Genetic Variation · hard · theory
Which type of reproduction generally produces MORE variation among offspring?
A. sexual reproduction ✓ Correct
B. budding
C. asexual reproduction
D. binary fission
Solution: Sexual reproduction mixes genes from two parents, producing greater variation.
Q3 — Genetic Variation · medium · theory
Variations are important because they:
A. help a species adapt and survive in changing conditions ✓ Correct
B. reduce survival
C. always harm the organism
D. stop evolution
Solution: Useful variations improve the chances of survival and are the raw material for evolution.
Q4 — Genetic Variation · hard · theory
A sudden, permanent change in the gene (DNA) of an organism is called a:
A. adaptation
B. reproduction
C. mutation ✓ Correct
D. variation only
Solution: A mutation is a change in the DNA that can create new variations.
Q5 — Genetic Variation · medium · theory
In human beings, the total number of chromosomes in a body cell is:
A. 46 (23 pairs) ✓ Correct
B. 23
C. 48
D. 44
Solution: Humans have 46 chromosomes arranged in 23 pairs.
Q6 — Genetic Variation · hard · theory
A human female has the sex chromosomes ______ and a male has ______:
A. XX; XX
B. XX; XY ✓ Correct
C. XY; XX
D. XY; XY
Solution: Females are XX and males are XY.
Q7 — Genetic Variation · hard · theory
The sex of a human child is determined by the:
A. temperature
B. father (whether the sperm carries X or Y) ✓ Correct
C. mother only
D. both equally at random
Solution: The mother always gives X; the father's sperm (X or Y) decides whether the child is a girl (XX) or boy (XY).
Q8 — Genetic Variation · medium · theory
Traits that are passed from parents to offspring through genes are called:
A. learned traits
B. inherited traits ✓ Correct
C. acquired traits
D. temporary traits
Solution: Inherited (genetic) traits are transmitted through genes to the next generation.
Q9 — Genetic Variation · hard · theory
A trait developed during an individual's lifetime (like a scar or learned skill) is:
A. a mutation
B. an inherited trait
C. an acquired trait that is not inherited ✓ Correct
D. always passed to offspring
Solution: Acquired traits arise from the environment and are not passed on to offspring genetically.
Q10 — Genetic Variation · medium · theory
Variation ultimately provides the basis for the process of:
A. evolution ✓ Correct
B. digestion
C. excretion
D. respiration
Solution: Variations, acted on by natural selection, drive the evolution of species over time.
Q11 — Genetic Variation · easy · theory
Which type of reproduction generally produces offspring with more genetic variation?
A. Binary fission
B. Sexual reproduction ✓ Correct
C. Asexual reproduction
D. Budding
Solution: Sexual reproduction mixes genes from two parents (through gamete formation and fertilisation), so it produces offspring that differ from each other. Asexual methods such as budding and binary fission give near-identical copies.
Q12 — Genetic Variation · medium · theory
A sudden, heritable change in the DNA (genetic material) of an organism is known as a:
A. Adaptation
B. Segregation
C. Fertilisation
D. Mutation ✓ Correct
Solution: A mutation is a sudden change in the DNA sequence that can be passed on to offspring. Mutations are an important original source of new genetic variation in a population.
Q13 — Genetic Variation · medium · theory
Offspring produced by asexual reproduction are usually genetically identical to the parent. What is the main reason for this?
A. They are formed by the fusion of two different gametes
B. They always carry many new mutations
C. They inherit genes from two different parents
D. They receive all their genes from a single parent without any mixing ✓ Correct
Solution: In asexual reproduction there is only one parent and no fusion of gametes, so the offspring get a copy of the same set of genes. Without mixing of genes from two parents, there is very little variation.
Q14 — Genetic Variation · hard · theory
Two farmers grow the same crop. Farmer A propagates plants only by cuttings (asexually), while Farmer B grows them from seeds produced by cross-pollination. If a new disease strikes, whose field is more likely to contain at least some resistant plants, and why?
A. Farmer A, because genetically identical plants always resist disease
B. Farmer B, because sexual reproduction creates more genetic variation among the plants ✓ Correct
C. Both equally, because variation does not affect disease resistance
D. Neither, because disease resistance can never be inherited
Solution: Farmer A's plants are genetic copies, so if one is susceptible all are. Farmer B's seed-grown plants vary genetically, so some individuals are more likely to carry resistance and survive the disease.
Q15 — Genetic Variation · hard · theory
Assertion (A): Genetic variation within a species is important for evolution. Reason (R): Natural selection acts on the variation present in a population, favouring individuals better suited to the environment. Choose the correct option.
A. Both A and R are true, but R is not the correct explanation of A
B. A is false but R is true
C. A is true but R is false
D. Both A and R are true, and R is the correct explanation of A ✓ Correct
Solution: Both statements are true. Evolution needs variation to work on, and natural selection is exactly the process that acts on that variation, favouring better-suited individuals. So R correctly explains why variation matters for evolution.