Heredity and Evolution (Class 10 Science)
Heredity is the process of passing traits from parents to offspring. Understanding heredity helps us comprehend how characteristics are inherited across ge
TL;DR: Heredity is the process of passing traits from parents to offspring. Understanding heredity helps us comprehend how characteristics are inherited acro…
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Heredity is the process of passing traits from parents to offspring. Understanding heredity helps us comprehend how characteristics are inherited across ge
Heredity and Evolution MCQs with Answers & Explanations
Q1. What is the unit of heredity called?
- Allele
- Chromosome
- Gene ✓ (correct)
- Nucleus
Explanation: A gene is the unit of heredity that carries information for specific traits and is passed from parents to offspring.
Q2. Who is known as the father of genetics?
- Louis Pasteur
- Robert Hooke
- Charles Darwin
- Gregor Mendel ✓ (correct)
Explanation: Gregor Mendel conducted experiments on pea plants and established the fundamental laws of inheritance.
Q3. In Mendel's monohybrid cross, what was the phenotypic ratio in F2 generation?
- 3:1 ✓ (correct)
- 1:2:1
- 9:3:3:1
- 1:1
Explanation: The 3:1 ratio appeared in the F2 generation showing that the dominant trait appeared three times more often than the recessive.
Q4. What are alleles?
- Recessive genes only
- Different forms of the same gene ✓ (correct)
- Dominant genes only
- Different genes on same chromosome
Explanation: Alleles are alternate forms of a gene that code for different versions of the same trait.
Q5. Which of the following is a dominant trait in humans?
- Red hair
- Attached earlobes
- Rolling tongue ✓ (correct)
- Blue eyes
Explanation: The ability to roll the tongue is a dominant trait, requiring only one dominant allele for expression.
Q6. What is a homozygous genotype?
- Aa or Bb
- Different alleles
- Aa
- AA or aa ✓ (correct)
Explanation: Homozygous means both alleles are the same, either AA (homozygous dominant) or aa (homozygous recessive).
Q7. In a test cross, what is the ratio obtained when a homozygous dominant is crossed with homozygous recessive?
- All dominant ✓ (correct)
- 3:1
- 1:2:1
- 1:1
Explanation: A test cross with a homozygous recessive produces all dominant offspring in the F1 generation.
Q8. Which chromosome pair determines the sex in humans?
- Chromosome 10
- Chromosome 23 ✓ (correct)
- Chromosome 1
- Chromosome 5
Explanation: Chromosome 23 is the sex chromosome pair (XX for females, XY for males) that determines biological sex.
Q9. What is a variation in biology?
- Change in environment
- Mutation in genes
- Differences between individuals of same species ✓ (correct)
- Disease in organism
Explanation: Variation refers to the differences in traits among individuals of the same species due to genetic and environmental factors.
Q10. Which process leads to evolution according to Darwin?
- Adaptation
- Genetic drift
- Mutation
- Natural selection ✓ (correct)
Explanation: Natural selection is the mechanism Darwin proposed where organisms with favorable traits survive and reproduce more successfully.
Frequently Asked Questions
What is the difference between dominant and recessive traits?
Dominant traits are expressed in heterozygous (Aa) individuals, while recessive traits appear only in homozygous recessive (aa) individuals. A dominant allele masks the effect of a recessive allele.
Can two brown-eyed parents have a blue-eyed child?
Yes, if both parents are heterozygous for the brown eye trait (Bb). Each can contribute the recessive blue eye allele (b), resulting in a blue-eyed child (bb).
More Class 10 Science MCQs
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