Question 1

Q1. During transcription in eukaryotes, which enzyme is directly responsible for synthesis of mRNA?

Accepted Answer

Option B: RNA polymerase II. RNA polymerase II synthesizes hnRNA (precursor of mRNA) in eukaryotes. Other polymerases synthesize rRNA or have different roles.

Question 2

Q2. During translation, the correct order of events is:

Accepted Answer

Option B: Initiation → Elongation → Termination. Protein synthesis begins with initiation, continues with elongation of polypeptide chain, and ends with termination at stop codon.

Question 3

Q3. Which immunoglobulin is most abundant in human blood serum?

Accepted Answer

Option C: IgG. IgG constitutes about 75% of serum antibodies and provides long-term immunity.

Question 4

Q4. If allele frequency in a population remains constant generation after generation, this condition is known as:

Accepted Answer

Option C: Hardy-Weinberg equilibrium. Hardy-Weinberg equilibrium states that allele frequencies remain constant in absence of evolutionary forces.

Question 5

Q5. Double fertilization in angiosperms results in formation of:

Accepted Answer

Option B: Embryo and endosperm. One male gamete fuses with egg (zygote), another with polar nuclei (endosperm).

Question 6

Q6. In a pedigree, a trait appears only in males and is passed from mother to sons. The most likely inheritance is:

Accepted Answer

Option B: X-linked recessive. X-linked recessive traits often appear in males and are transmitted through carrier mothers.

Question 7

Q7. A cloning vector must have which essential feature?

Accepted Answer

Option B: Origin of replication. Ori (origin of replication) is essential for replication of vector inside host cell.

Question 8

Q8. In an ecosystem, which pyramid is always upright?

Accepted Answer

Option C: Pyramid of energy. Energy decreases at each trophic level due to loss as heat, so energy pyramid is always upright.

Question 9

Q9. Restriction enzymes recognize:

Accepted Answer

Option C: Specific palindromic DNA sequences. Restriction endonucleases cut DNA at specific palindromic recognition sites.

Question 10

Q10. In PCR, which component is NOT directly required?

Accepted Answer

Option D: Ribosomes. Ribosomes are not involved in PCR; it is an in vitro DNA amplification process.

Question 11

Q11. Vaccination helps in disease prevention by:

Accepted Answer

Option C: Stimulating memory immune response. Vaccines prepare immune system to respond faster upon real infection.

Question 12

Q12. In diabetes mellitus, which hormone is deficient or ineffective?

Accepted Answer

Option B: Insulin. Insulin regulates blood glucose; its deficiency leads to hyperglycemia.

Question 13

Q13. Excess nutrients in water bodies lead to:

Accepted Answer

Option B: Eutrophication. Nutrient overload causes algal bloom and oxygen depletion.

Question 14

Q14. Assertion (A): Crossing over occurs during pachytene stage of prophase I. Reason (R): It increases genetic variation in offspring.

Accepted Answer

Option A: Both A and R are true and R explains A. Crossing over occurs in pachytene and leads to recombination, increasing variation.

Question 15

Q15. Assertion (A): Lac operon is induced in absence of lactose. Reason (R): Repressor binds to operator and blocks transcription.

Accepted Answer

Option D: A false R true. Lac operon is OFF without lactose because repressor blocks transcription.

Question 16

Q16. Case Study: A patient shows uncontrolled cell division forming a mass of cells that can spread to other organs. What is the most likely condition?

Accepted Answer

Option B: Cancer. Uncontrolled proliferation and metastasis are characteristic of cancer.

Question 17

Q17. Case Study: In recombinant insulin production, human insulin gene is inserted into bacteria which then produce insulin. Why is E. coli commonly used?

Accepted Answer

Option C: It has well-known genetics and rapid multiplication. E. coli is easy to manipulate and multiplies rapidly, making it ideal for recombinant protein production.

Question 18

Q18. If recombination frequency between two genes is 20%, they are:

Accepted Answer

Option C: Closely linked. Lower recombination frequency indicates genes are closely located on same chromosome.

Question 19

Q19. A bacterial population becomes resistant to antibiotics over time due to:

Accepted Answer

Option B: Natural selection. Antibiotic-resistant bacteria survive and reproduce, leading to natural selection.

Question 20

Q20. A population has 16% individuals showing recessive phenotype (aa). What is frequency of dominant allele (A)?

Accepted Answer

Option B: 0.6. q² = 0.16 → q = 0.4 → p = 1 - 0.4 = 0.6

Mock Test 03 Performance Solutions

Detailed Question Analysis

Q1. During transcription in eukaryotes, which enzyme is directly responsible for synthesis of mRNA?

Q2. During translation, the correct order of events is:

Q3. Which immunoglobulin is most abundant in human blood serum?

Q4. If allele frequency in a population remains constant generation after generation, this condition is known as:

Q5. Double fertilization in angiosperms results in formation of:

Q6. In a pedigree, a trait appears only in males and is passed from mother to sons. The most likely inheritance is:

Q7. A cloning vector must have which essential feature?

Q8. In an ecosystem, which pyramid is always upright?

Q9. Restriction enzymes recognize:

Q10. In PCR, which component is NOT directly required?

Q11. Vaccination helps in disease prevention by:

Q12. In diabetes mellitus, which hormone is deficient or ineffective?

Q13. Excess nutrients in water bodies lead to:

Q14. Assertion (A): Crossing over occurs during pachytene stage of prophase I. Reason (R): It increases genetic variation in offspring.

Q15. Assertion (A): Lac operon is induced in absence of lactose. Reason (R): Repressor binds to operator and blocks transcription.

Q16. Case Study: A patient shows uncontrolled cell division forming a mass of cells that can spread to other organs. What is the most likely condition?

Q17. Case Study: In recombinant insulin production, human insulin gene is inserted into bacteria which then produce insulin. Why is E. coli commonly used?

Q18. If recombination frequency between two genes is 20%, they are:

Q19. A bacterial population becomes resistant to antibiotics over time due to:

Q20. A population has 16% individuals showing recessive phenotype (aa). What is frequency of dominant allele (A)?

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Mock Test 03 Performance Solutions

Detailed Question Analysis

Q1. During transcription in eukaryotes, which enzyme is directly responsible for synthesis of mRNA?

Q2. During translation, the correct order of events is:

Q3. Which immunoglobulin is most abundant in human blood serum?

Q4. If allele frequency in a population remains constant generation after generation, this condition is known as:

Q5. Double fertilization in angiosperms results in formation of:

Q6. In a pedigree, a trait appears only in males and is passed from mother to sons. The most likely inheritance is:

Q7. A cloning vector must have which essential feature?

Q8. In an ecosystem, which pyramid is always upright?

Q9. Restriction enzymes recognize:

Q10. In PCR, which component is NOT directly required?

Q11. Vaccination helps in disease prevention by:

Q12. In diabetes mellitus, which hormone is deficient or ineffective?

Q13. Excess nutrients in water bodies lead to:

Q14. Assertion (A): Crossing over occurs during pachytene stage of prophase I. Reason (R): It increases genetic variation in offspring.

Q15. Assertion (A): Lac operon is induced in absence of lactose. Reason (R): Repressor binds to operator and blocks transcription.

Q16. Case Study: A patient shows uncontrolled cell division forming a mass of cells that can spread to other organs. What is the most likely condition?

Q17. Case Study: In recombinant insulin production, human insulin gene is inserted into bacteria which then produce insulin. Why is E. coli commonly used?

Q18. If recombination frequency between two genes is 20%, they are:

Q19. A bacterial population becomes resistant to antibiotics over time due to:

Q20. A population has 16% individuals showing recessive phenotype (aa). What is frequency of dominant allele (A)?

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