GATE IN 2023 | GA | Question: 8

Question

The information contained in DNA is used to synthesize proteins that are necessary for the functioning of life. DNA is composed of four nucleotides: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G). The information contained in DNA can then be thought of as a sequence of these four nucleotides: A, T, C, and G. DNA has coding and non-coding regions. Coding regions-where the sequence of these nucleotides are read in groups of three to produce individual amino acids - constitute only about $2 \%$ of human DNA. For example, the triplet of nucleotides CCG codes for the amino acid glycine, while the triplet GGA codes for the amino acid proline. Multiple amino acids are then assembled to form a protein.

Based only on the information provided above, which of the following statements can be logically inferred with certainty?

1. The majority of human DNA has no role in the synthesis of proteins.
2. The function of about $98 \%$ of human DNA is not understood.

• A. only (i)
• B. only (ii)
• C. both (i) and (ii)
• D. neither (i) nor (ii)

Answer 1

Given facts:

1. The information in DNA is utilized for protein synthesis.
2. DNA consists of four nucleotides: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).
3. Thus, the information in DNA can be viewed as a sequence of these nucleotides: A, T, C, and G.
4. DNA contains coding and non-coding regions.
5. Coding regions—where nucleotide sequences are read in triplets to produce amino acids—make up only about 2% of human DNA.
6. These amino acids are then linked to form proteins.

Let's carefully analyze the statements:

Statement (i): "The majority of human DNA has no role in the synthesis of proteins."
Analysis: The information states that coding regions, where nucleotides are read in triplets for amino acid production, make up 2% of human DNA. However, it doesn't specify that the remaining 98% has no role in protein synthesis. Non-coding regions could potentially have indirect roles not mentioned. Therefore, this statement cannot be inferred with certainty.

Statement (ii): "The function of about 98% of human DNA is not understood."
Analysis: While we know that 98% of DNA is non-coding, the passage provides no information about our understanding of this DNA's function. It only states that it's not directly involved in coding for amino acids. The lack of coding function doesn't imply a lack of understanding. Thus, this statement also cannot be inferred.

Conclusion: Neither statement can be logically inferred with certainty from the given information. The correct answer is option D: neither (i) nor (ii).

While answering , such reasoning questions , we only need to consider, what is given in the given paragraph and then draw inferences acordingly . 

Comments

good solution

Answer 2

500. The above passage describes the coding region in detail which constitute only 2% of human DNA. But that doesn’t mean that the rest 98% (non-coding region) don’t play any role in the synthesis of proteins. The details are absent here, doesn’t mean that functions are not yet discovered in the medical domain. 

Answer 3

The majority of human DNA has no role in the synthesis of proteins: This statement is true and can be directly inferred from the passage. It explicitly states that coding regions, responsible for protein synthesis, constitute only 2% of human DNA. Therefore, the remaining 98% must have other functions or no known function at this time.

(ii) The function of about 98% of human DNA is not understood: This statement is not necessarily true. While the passage mentions that the function of most of human DNA is not yet understood, it doesn't guarantee that it has no function at all. There might be roles for non-coding DNA that are still being discovered and researched. The information only emphasizes the lack of current understanding, not the absence of any potential function