Question 1

Q1. The enzyme that unwinds the DNA helix during replication is:

Accepted Answer

Option C: Helicase. Helicase breaks hydrogen bonds and unwinds the DNA double helix at the replication fork.

Question 2

Q2. The codon is located on:

Accepted Answer

Option C: mRNA. Codons are triplet nucleotide sequences present on mRNA that code for amino acids.

Question 3

Q3. Which law explains the expression of only one allele in heterozygous condition?

Accepted Answer

Option B: Law of dominance. Dominant allele masks the effect of recessive allele in heterozygous condition.

Question 4

Q4. Which part of nephron is responsible for selective reabsorption?

Accepted Answer

Option C: Proximal convoluted tubule. PCT reabsorbs glucose, amino acids, ions, and water selectively.

Question 5

Q5. Which antibody is mainly involved in allergic reactions?

Accepted Answer

Option C: IgE. IgE triggers histamine release from mast cells causing allergy symptoms.

Question 6

Q6. A cross between two heterozygous tall plants produces a dwarf plant. This indicates:

Accepted Answer

Option C: Segregation of recessive allele. Recessive allele expresses when homozygous (tt) appears in F2 generation.

Question 7

Q7. During meiosis, crossing over occurs between:

Accepted Answer

Option C: Non-sister chromatids of homologous chromosomes. Exchange of genetic material occurs between non-sister chromatids in pachytene stage.

Question 8

Q8. Which trophic level receives maximum energy in an ecosystem?

Accepted Answer

Option C: Producers. Producers capture solar energy; energy decreases at higher levels.

Question 9

Q9. Restriction enzymes are used in biotechnology because they:

Accepted Answer

Option B: Cut DNA at specific sites. They cut DNA at specific palindromic sequences for gene manipulation.

Question 10

Q10. The process of conversion of DNA into RNA is called:

Accepted Answer

Option C: Transcription. Transcription synthesizes RNA from DNA template.

Question 11

Q11. Copper-T prevents pregnancy mainly by:

Accepted Answer

Option B: Preventing implantation. Copper ions reduce sperm motility and prevent implantation.

Question 12

Q12. HIV primarily attacks:

Accepted Answer

Option C: Helper T-cells. HIV targets CD4+ helper T cells, weakening immune system.

Question 13

Q13. The main reason energy is lost between trophic levels is:

Accepted Answer

Option B: Respiration and heat loss. Energy is lost as heat during metabolic processes.

Question 14

Q14. Assertion (A): DNA replication is semiconservative. Reason (R): Each daughter DNA has one parental strand and one new strand.

Accepted Answer

Option A: Both true and R explains A. Meselson-Stahl experiment proved semiconservative replication.

Question 15

Q15. Assertion (A): Genetic drift is more effective in large populations. Reason (R): Random changes affect allele frequency more in small populations.

Accepted Answer

Option B: A false R true. Genetic drift is significant in small populations, not large ones.

Question 16

Q16. Case Study: A patient shows excessive urination, thirst, and high blood glucose levels. What is the most likely condition?

Accepted Answer

Option A: Diabetes mellitus. Insulin deficiency leads to high blood glucose and polyuria.

Question 17

Q17. Case Study: In recombinant DNA technology, bacteria produce human insulin. Why is plasmid used?

Accepted Answer

Option B: It acts as cloning vector. Plasmids carry foreign genes into bacterial cells.

Question 18

Q18. If recombination frequency between two genes is 1%, they are:

Accepted Answer

Option C: Closely linked. Low recombination frequency indicates close linkage.

Question 19

Q19. In a Hardy-Weinberg population, if p = 0.6, q is:

Accepted Answer

Option B: 0.4. p + q = 1 → q = 0.4

Question 20

Q20. Which of the following shows highest species diversity?

Accepted Answer

Option B: Tropical rainforest. Tropical rainforests have stable climate and high biodiversity.

Mock Test 06 Performance Solutions

Detailed Question Analysis

Q1. The enzyme that unwinds the DNA helix during replication is:

Q2. The codon is located on:

Q3. Which law explains the expression of only one allele in heterozygous condition?

Q4. Which part of nephron is responsible for selective reabsorption?

Q5. Which antibody is mainly involved in allergic reactions?

Q6. A cross between two heterozygous tall plants produces a dwarf plant. This indicates:

Q7. During meiosis, crossing over occurs between:

Q8. Which trophic level receives maximum energy in an ecosystem?

Q9. Restriction enzymes are used in biotechnology because they:

Q10. The process of conversion of DNA into RNA is called:

Q11. Copper-T prevents pregnancy mainly by:

Q12. HIV primarily attacks:

Q13. The main reason energy is lost between trophic levels is:

Q14. Assertion (A): DNA replication is semiconservative. Reason (R): Each daughter DNA has one parental strand and one new strand.

Q15. Assertion (A): Genetic drift is more effective in large populations. Reason (R): Random changes affect allele frequency more in small populations.

Q16. Case Study: A patient shows excessive urination, thirst, and high blood glucose levels. What is the most likely condition?

Q17. Case Study: In recombinant DNA technology, bacteria produce human insulin. Why is plasmid used?

Q18. If recombination frequency between two genes is 1%, they are:

Q19. In a Hardy-Weinberg population, if p = 0.6, q is:

Q20. Which of the following shows highest species diversity?

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Mock Test 06 Performance Solutions

Detailed Question Analysis

Q1. The enzyme that unwinds the DNA helix during replication is:

Q2. The codon is located on:

Q3. Which law explains the expression of only one allele in heterozygous condition?

Q4. Which part of nephron is responsible for selective reabsorption?

Q5. Which antibody is mainly involved in allergic reactions?

Q6. A cross between two heterozygous tall plants produces a dwarf plant. This indicates:

Q7. During meiosis, crossing over occurs between:

Q8. Which trophic level receives maximum energy in an ecosystem?

Q9. Restriction enzymes are used in biotechnology because they:

Q10. The process of conversion of DNA into RNA is called:

Q11. Copper-T prevents pregnancy mainly by:

Q12. HIV primarily attacks:

Q13. The main reason energy is lost between trophic levels is:

Q14. Assertion (A): DNA replication is semiconservative. Reason (R): Each daughter DNA has one parental strand and one new strand.

Q15. Assertion (A): Genetic drift is more effective in large populations. Reason (R): Random changes affect allele frequency more in small populations.

Q16. Case Study: A patient shows excessive urination, thirst, and high blood glucose levels. What is the most likely condition?

Q17. Case Study: In recombinant DNA technology, bacteria produce human insulin. Why is plasmid used?

Q18. If recombination frequency between two genes is 1%, they are:

Q19. In a Hardy-Weinberg population, if p = 0.6, q is:

Q20. Which of the following shows highest species diversity?

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