Read the given statements that refer to natural selection.
(i) Competition between organisms alters their genes.
(ii) Parent organisms transmit useful and adaptable characteristics to the next generation.
(iii) Organisms vary in their adaptations
. (iv) Only one species can occupy an ecological niche.
(v) Well-adapted organisms survive and reproduce.
Which statements summarise the theory of evolution by natural selection?

Options

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

Answer

To determine which statements summarize the theory of evolution by natural selection, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement (i): Competition between organisms alters their genes.**
- This statement is misleading. While competition does occur among organisms for resources, it does not directly alter their genes. Genetic changes occur over generations through mutations and natural selection, not through competition alone.
- **Conclusion:** This statement is **not correct**.

2. **Statement (ii): Parent organisms transmit useful and adaptable characteristics to the next generation.**
- This statement is accurate. In natural selection, advantageous traits that help organisms survive and reproduce are passed on to the next generation through heredity.
- **Conclusion:** This statement is **correct**.

3. **Statement (iii): Organisms vary in their adaptations.**
- This statement is true. Within a species, individuals often have variations in traits that affect their ability to survive in their environment. This variation is crucial for natural selection to occur.
- **Conclusion:** This statement is **correct**.

4. **Statement (iv): Only one species can occupy an ecological niche.**
- This statement is not entirely accurate. While it is true that two species cannot occupy the exact same niche due to competition (known as the competitive exclusion principle), multiple species can coexist in overlapping niches by utilizing different resources or adapting to different conditions.
- **Conclusion:** This statement is **not correct**.

5. **Statement (v): Well-adapted organisms survive and reproduce.**
- This statement is a fundamental principle of natural selection. Organisms that are better adapted to their environment are more likely to survive and reproduce, passing their advantageous traits to the next generation.
- **Conclusion:** This statement is **correct**.

### Summary of Correct Statements:
The statements that summarize the theory of evolution by natural selection are:
- (ii) Parent organisms transmit useful and adaptable characteristics to the next generation.
- (iii) Organisms vary in their adaptations.
- (v) Well-adapted organisms survive and reproduce.

Thus, the correct statements are **(ii), (iii), and (v)**.