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Heredity — Class 10 CBSE Science MCQs with Solutions
Free Class 10 CBSE Science Heredity MCQs with step-by-step solutions. Practise online on Prepizo — no login needed.
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Sample questions with solutions
Q1 — easy
Transmission of genetically inherited traits from parents to offspring is called:
A. Variation
B. Heredity ✓ Correct
C. Evolution
D. Mutation
Solution: Heredity is the passage of genetic traits down generations.
Q2 — easy
Differences shown by individuals of same species in a population are known as:
A. Heredity
B. Variations ✓ Correct
C. Alleles
D. Clones
Solution: Variations are morphological or physiological differences among individuals.
Q3 — easy
Gregor Johann Mendel conducted classic genetic hybridization experiments on:
A. Sweet pea
B. Garden pea (Pisum sativum) ✓ Correct
C. Wild mustard
D. Fruit fly
Solution: Mendel worked on garden pea plants (*Pisum sativum*).
Q4 — easy
Cross involving single pair of contrasting characters (e.g. Tall × Dwarf) is a:
A. Dihybrid cross
B. Monohybrid cross ✓ Correct
C. Test cross
D. Back cross
Solution: Monohybrid crosses trace one trait pair.
Q5 — easy
Phenotypic ratio obtained in F₂ generation of a Mendelian Monohybrid cross is:
A. 1 : 2 : 1
B. 3 : 1 ✓ Correct
C. 9 : 3 : 3 : 1
D. 2 : 1
Solution: F₂ monohybrid phenotype = 3 Dominant : 1 Recessive.
Q6 — easy
Genotypic ratio obtained in F₂ generation of a Mendelian Monohybrid cross is:
A. 3 : 1
B. 1 : 2 : 1 ✓ Correct
C. 9 : 3 : 3 : 1
D. 1 : 1
Solution: F₂ monohybrid genotype = 1 TT : 2 Tt : 1 tt.
Q7 — easy
Phenotypic ratio obtained in F₂ generation of a Mendelian Dihybrid cross is:
A. 3 : 1
B. 1 : 2 : 1
C. 9 : 3 : 3 : 1 ✓ Correct
D. 1 : 1 : 1 : 1
Solution: Dihybrid F₂ phenotypic ratio = 9 : 3 : 3 : 1.
Q8 — easy
Allele that expresses its phenotype in presence of contrasting allele (e.g. 'T' in Tt) is:
A. Recessive allele
B. Dominant allele ✓ Correct
C. Co-dominant allele
D. Recessive trait
Solution: Dominant alleles mask recessive alleles in heterozygotes.
Q9 — easy
Allele whose phenotypic effect is masked in heterozygous condition (e.g. 't' in Tt) is:
A. Dominant
B. Recessive ✓ Correct
C. Co-dominant
D. Hybrid
Solution: Recessive alleles express only in homozygous state.
Q10 — easy
Total number of chromosome pairs in a normal human somatic cell is:
A. 23 individual
B. 23 pairs (46 chromosomes) ✓ Correct
C. 46 pairs
D. 22 pairs
Solution: Human cells contain 23 pairs (46) of chromosomes.
Q11 — easy
Number of autosome pairs in human body cells is:
A. 23 pairs
B. 22 pairs (44 autosomes) ✓ Correct
C. 1 pair
D. 21 pairs
Solution: Humans have 22 autosome pairs and 1 sex chromosome pair.
Q12 — easy
Sex chromosomes present in human males are:
A. XX
B. XY ✓ Correct
C. YY
D. XO
Solution: Human males possess heterametic XY sex chromosomes.
Q13 — easy
Sex chromosomes present in human females are:
A. XY
B. XX ✓ Correct
C. YY
D. XO
Solution: Human females possess homogametic XX sex chromosomes.
Q14 — easy
In human beings, sex of a newborn child is determined by:
A. Mother's egg cell
B. Father's sperm cell (carrying X or Y chromosome) ✓ Correct
C. Environmental temperature
D. Nutrition
Solution: Paternal sperm provides either X or Y chromosome.
Q15 — easy
Which combination of sex chromosomes results in a female child?
A. 44 + XY
B. 44 + XX ✓ Correct
C. 44 + YY
D. 45 + XO
Solution: 44 autosomes + XX sex chromosomes yields a female.