Statement - I : Non-homologous DNA will attach to a DNA probe.
Statement - II : At high temperature, two complementary DNA strands will anneal.

Options

A. Only statement - I is true
B. Only statement - II is true
C. Both statements - I & II are true
D. Both statements - I & II are false

Answer

To analyze the statements provided, let's break down each statement step by step.

### Step 1: Understand Statement I
**Statement I:** Non-homologous DNA will attach to a DNA probe.

- **Definition of a DNA Probe:** A DNA probe is a short, single-stranded DNA sequence that is labeled (often radioactively) and is used to detect specific sequences of DNA.
- **Homologous vs. Non-Homologous DNA:** Homologous DNA refers to DNA sequences that are similar or identical in structure and sequence, while non-homologous DNA refers to sequences that are different.
- **Analysis:** DNA probes specifically bind to complementary sequences. Therefore, non-homologous DNA, which does not have a complementary sequence, will not attach to a DNA probe.

**Conclusion for Statement I:** This statement is false.

### Step 2: Understand Statement II
**Statement II:** At high temperature, two complementary DNA strands will anneal.

- **Annealing Process:** Annealing refers to the process where two complementary DNA strands bind together.
- **High Temperature Effect:** In techniques like PCR (Polymerase Chain Reaction), high temperatures are used to denature DNA strands, meaning they separate into single strands. After denaturation, the temperature is lowered to allow complementary strands to anneal.
- **Analysis:** The statement incorrectly suggests that at high temperatures, complementary strands will anneal. In reality, high temperatures cause the strands to separate (denature), and annealing occurs when the temperature is lowered.

**Conclusion for Statement II:** This statement is also false.

### Final Conclusion
Both statements are false.

### Answer:
Both Statement I and Statement II are false.

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