Find out the correct statement:
a) Life spans of organisms are necessarily correlated with their sizes
b) The sizes crows and parrots are not very different, so their life spans are almost similar
c) A peepal tree has much shorter life span as compared to a mango tree
d) Reproduction is essential for continuity of species on the earth

Options

A. Life spans of organisms are necessarily correlated with their sizes
B. The sizes crows and parrots are not very different, so their life spans are almost similar
C. A peepal tree has much shorter life span as eompared to a mango tree
D. Reproduction is essential for continuity of species on the earth

Answer

To solve the question, we need to analyze each statement provided and determine which one is correct.

### Step-by-Step Solution:

1. **Analyze Statement A**: "Life spans of organisms are necessarily correlated with their sizes."
- Lifespan is the duration from birth to death of an organism. While there may be some correlation between size and lifespan, it is not necessarily true for all organisms. For example, a crow and a parrot have similar sizes but vastly different lifespans (crows live about 10-15 years, while parrots can live up to 140 years). Therefore, this statement is **incorrect**.

2. **Analyze Statement B**: "The sizes of crows and parrots are not very different, so their life spans are almost similar."
- As established, while crows and parrots are similar in size, their lifespans differ significantly. This statement incorrectly assumes that similar size leads to similar lifespan. Thus, this statement is also **incorrect**.

3. **Analyze Statement C**: "A peepal tree has a much shorter lifespan as compared to a mango tree."
- The lifespan of a mango tree is typically around 100-150 years, while a peepal tree can live for 1500 to 2500 years. This statement is incorrect because it misrepresents the lifespan comparison between the two trees. Therefore, this statement is **incorrect**.

4. **Analyze Statement D**: "Reproduction is essential for continuity of species on the earth."
- Reproduction, whether sexual or asexual, is indeed essential for the survival and continuity of species. Offspring are necessary for the continuation of any species. This statement is **correct**.

### Conclusion:
The correct statement is **D**: "Reproduction is essential for continuity of species on the earth."

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