Which is correct sequence according to increasing molecular weight?

Options

A. tRNA-DNA-rRNA
B. tRNA-rRNA-DNA
C. rRNA-DNA-tRNA
D. DNA-tRNA-rRNA

Answer

To solve the question regarding the correct sequence according to increasing molecular weight among tRNA, rRNA, and DNA, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Molecules**:
- tRNA (transfer RNA) is involved in protein synthesis and is relatively small.
- rRNA (ribosomal RNA) is a component of ribosomes and is larger than tRNA.
- DNA (deoxyribonucleic acid) is the genetic material and is the largest among these three.

2. **Determine the Size of Each Molecule**:
- tRNA typically consists of about 75 to 95 nucleotides.
- rRNA can range from about 3500 to 5000 nucleotides, depending on the type of rRNA.
- DNA molecules can be very large, often consisting of millions of nucleotides.

3. **Compare Molecular Weights**:
- Since tRNA is the smallest, it has the lowest molecular weight.
- rRNA, being larger than tRNA, has a higher molecular weight.
- DNA, being the largest, has the highest molecular weight.

4. **Establish the Sequence**:
- Based on the sizes and molecular weights, the correct order from smallest to largest is: tRNA < rRNA < DNA.

5. **Select the Correct Option**:
- The correct sequence according to increasing molecular weight is option B: tRNA, rRNA, DNA.

### Final Answer:
The correct sequence according to increasing molecular weight is **Option B: tRNA, rRNA, DNA**.

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