Select the correct statement-

Options

A. Miller experiment is related to organic evolution.
B. Placental mammals in Australia are result of adaptive radiation.
C. Mutations are directional.
D. Vertebrate hearts represent Analogous organs.

Answer

To solve the question, we need to evaluate each of the provided statements and determine which one is correct. Here’s a step-by-step breakdown:

### Step 1: Analyze the First Statement
**Statement:** Miller experiment is related to organic evolution.

- The Miller-Urey experiment was designed to simulate the conditions of early Earth and test the hypothesis of abiogenesis (the origin of life from non-living matter). While it does relate to the origins of organic compounds, it does not directly address organic evolution, which refers to the changes in living organisms over time. Therefore, this statement is **incorrect**.

**Hint:** Consider the distinction between the origin of life and the evolution of life.

### Step 2: Analyze the Second Statement
**Statement:** Placental mammals in Australia are a result of adaptive radiation.

- Adaptive radiation is a process where organisms diversify rapidly into a variety of forms to adapt to different environments. In Australia, placental mammals have evolved into various forms due to the unique ecological niches available. This statement is **correct**.

**Hint:** Think about how species adapt to their environments and how this leads to diversification.

### Step 3: Analyze the Third Statement
**Statement:** Mutations are directional.

- Mutations are random changes in the genetic material. They do not occur in a specific direction or with a specific purpose. Therefore, this statement is **incorrect**.

**Hint:** Reflect on the nature of mutations and their randomness.

### Step 4: Analyze the Fourth Statement
**Statement:** Vertebrate hearts represent analogous organs.

- Vertebrate hearts are actually homologous organs, meaning they share a common structure but may have different functions across species. Analogous organs, on the other hand, serve similar functions but do not share a common structure. Thus, this statement is **incorrect**.

**Hint:** Differentiate between homologous and analogous structures.

### Conclusion
After evaluating all four statements, the only correct statement is the second one: "Placental mammals in Australia are a result of adaptive radiation."

### Final Answer
The correct statement is **Option 2**: Placental mammals in Australia are a result of adaptive radiation.