Which of the following criteria should be fulfilled by a molecule to act as a genetic material?
(i) It should be able to replicate.
(ii) It should be structurally and chemically stable.
(iii) It should be able to ndergor slow mutations.
(iv)It should be able to express itself in the form of 'Mendelian characters'

Options

A. (i) and (ii)
B. (ii) and (iii)
C. (i) and (ii), (iii)
D. (i),(ii),(iii) and (iv)

Explanation

To determine which criteria should be fulfilled by a molecule to act as genetic material, we can analyze each of the given statements step by step:

### Step 1: Ability to Replicate
The first criterion states that the molecule should be able to replicate. This means that the genetic material must have the ability to produce copies of itself. This is essential for passing genetic information from one generation to the next. In living organisms, DNA is known to replicate itself during cell division, ensuring that each new cell has the same genetic information as the parent cell.

**Hint:** Think about how DNA is copied during cell division.

### Step 2: Structural and Chemical Stability
The second criterion indicates that the genetic material should be structurally and chemically stable. Stability is crucial because it ensures that the genetic information is preserved over generations. If the genetic material were unstable, it could lead to frequent mutations or loss of information. DNA, with its double-helix structure, provides this stability due to its complementary base pairing and the sugar-phosphate backbone.

**Hint:** Consider why a stable structure is important for the integrity of genetic information.

### Step 3: Ability to Undergo Slow Mutations
The third criterion suggests that the genetic material should be able to undergo slow mutations. Mutations are changes in the genetic sequence, and while some mutations can be harmful, others can lead to variations that are beneficial for evolution. The ability to undergo slow mutations allows for genetic diversity while maintaining the overall integrity of the genetic material.

**Hint:** Reflect on the role of mutations in evolution and adaptation.

### Step 4: Expression in Mendelian Characters
The fourth criterion states that the genetic material should be able to express itself in the form of Mendelian characters. This means that the traits and characteristics governed by the genetic material should be observable and follow Mendelian inheritance patterns. Genes, which are segments of DNA, are responsible for these traits, and their expression is essential for the phenotype of an organism.

**Hint:** Think about how traits are passed from parents to offspring according to Mendel's laws.

### Conclusion
After analyzing all four criteria, we can conclude that all of them are essential for a molecule to act as genetic material. Therefore, the correct answer is that all four statements are true.

**Final Answer:** All of the above criteria should be fulfilled by a molecule to act as genetic material.