Introduction
This insect life cycle question is a common Primary Science graph question that tests both concept understanding and careful reading. Many students can read the bar chart values correctly, but they lose marks because they include the wrong stage or miss the phrase “after the egg has hatched”. Once you focus on what the question is really asking, this insect life cycle question becomes much easier to solve.
The Question / Scenario Explanation
Source: P5 Question 2
Question (as shown): The graph shows the length of time for each stage in the life cycle of insect T. How many days does it take for insect T to reach the adult stage after the egg has hatched?
From the graph:
Egg \(= 3\) days
Larva \(= 6\) days
Pupa \(= 9\) days
Adult \(= 10\) days
Step-by-Step Solution / Explanation
Step 1: Identify the key phrase in the question
The most important phrase is “after the egg has hatched”.
This means we do not include the egg stage in our calculation.
So for this insect life cycle question, we only count the stages after hatching and before becoming an adult.
Step 2: Read the relevant stages from the graph
After the egg hatches, the insect goes through:
- larva stage \(= 6\) days
- pupa stage \(= 9\) days
We stop when the insect reaches the adult stage, so we do not include the adult stage duration either.
Step 3: Add the correct durations
\(6 + 9 = 15\)
So it takes \(15\) days for the insect to reach the adult stage after the egg has hatched.
✅ Final Answer: \(15\) days
Step 4: Explain why the other answers are wrong
13 is wrong because it may come from adding the wrong stages or reading the graph inaccurately.
19 is wrong because students may include the adult stage by mistake.
28 is wrong because it includes all four stages: \(3 + 6 + 9 + 10\), but the question clearly says after the egg has hatched and asks only until the insect reaches the adult stage.
This is why \(15\) is the correct answer for this insect life cycle graph question.
Key Concepts Students Must Know
- An insect life cycle may be shown using a graph, table, or diagram.
- Students must read both the graph values and the wording of the question carefully.
- The phrase after the egg has hatched means the egg stage should not be counted.
- The phrase reach the adult stage means stop at the point the insect becomes an adult, so do not include the adult stage duration.
- Science graph questions often test understanding of sequence as well as data reading.
Exam Tips / Common Mistakes
Exam Tips
- Underline key phrases such as after the egg has hatched and reach the adult stage.
- List the stages in order before doing any addition.
- For an insect life cycle graph question, decide clearly which stages to include and which to exclude.
- Read the graph values carefully from the correct axis before calculating.
Common Mistakes
- Including the egg stage even though the question says after the egg has hatched.
- Including the adult stage duration even though the question asks when the insect reaches adulthood.
- Reading the bar heights wrongly from the graph.
- Adding all stages automatically without checking what the question actually asks.
Parent Insight
This insect life cycle question is a strong example of how Science requires both concept knowledge and precise reading. Many children understand life cycles, but they still lose marks when they do not pay attention to phrases like “after” and “reach”. Regular practice with graph-based Science questions helps students become more careful, accurate, and confident in exams.
Conclusion
In this insect life cycle graph question, we do not count the egg stage because the question says after the egg has hatched. We also do not count the adult stage duration because we stop when the insect reaches adulthood. So we add only the larva and pupa stages: \(6 + 9 = 15\). The correct answer is 15 days.
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