Grade: Grade 2 Subject: Science Unit: Life Cycles Lesson: 3 of 6 ACT: Science

Investigation Lab: Observing Life Cycles

Learn

Scientists learn about living things by observing them carefully. In this investigation lab, you will become a scientist and watch how living things grow and change over time.

What Do Scientists Do?

  • Observe: Look carefully at living things
  • Record: Write down or draw what they see
  • Measure: Use tools to find out how big things are
  • Compare: See what is the same and different

Tools Scientists Use

  • Magnifying glass: Makes small things look bigger
  • Ruler: Measures how long or tall something is
  • Science journal: A notebook to draw and write observations
  • Camera: Takes pictures to remember what things look like

Setting Up a Life Cycle Investigation

To study a life cycle, you need to:

  1. Choose a living thing to observe (seeds, caterpillars, tadpoles)
  2. Create a safe home for it
  3. Observe it every day at the same time
  4. Record what you see with drawings and words
  5. Look for changes over time

Examples

Example 1: Observing a Bean Seed

Day 1: The seed is small, brown, and hard. It is about 2 cm long.

Day 5: A tiny white root is poking out of the seed.

Day 10: A green stem is growing up. The stem is 3 cm tall.

Day 15: Two small leaves have opened. The plant is 8 cm tall.

Example 2: Observation Journal Entry

Date: March 5

What I observed: My caterpillar is eating a lot of leaves today. It looks fatter than yesterday. I can see stripes on its body.

Drawing: [Student would draw the caterpillar]

Measurement: The caterpillar is 4 cm long.

Example 3: Comparing Changes

Week What the Tadpole Looks Like
Week 1 Round body, long tail, no legs
Week 3 Body is bigger, tiny back legs starting
Week 5 Back legs are longer, front legs starting

Practice

Answer these questions about being a science investigator.

1. What tool would you use to see a tiny seed up close?

A) Ruler   B) Magnifying glass   C) Camera   D) Pencil

2. Why do scientists write in a journal every day?

A) To practice handwriting   B) To remember what they observed   C) To draw pictures   D) To do homework

3. A student wants to know how tall a plant has grown. Which tool should they use?

A) Magnifying glass   B) Camera   C) Ruler   D) Paintbrush

4. What does "observe" mean?

A) To guess   B) To look carefully   C) To run fast   D) To eat

5. Why is it important to observe at the same time each day?

A) Because you might forget   B) To see fair comparisons of changes   C) Because nighttime is too dark   D) To finish faster

6. A caterpillar was 2 cm on Monday. On Friday it was 5 cm. What happened?

A) The caterpillar got smaller   B) The caterpillar stayed the same   C) The caterpillar grew 3 cm   D) The ruler was broken

7. Which is the BEST observation?

A) The flower is pretty   B) The flower has 5 yellow petals and is 10 cm tall   C) I like flowers   D) Flowers are nice

8. What should you do FIRST when setting up a life cycle investigation?

A) Draw a picture   B) Choose a living thing to observe   C) Write a report   D) Clean up

9. Why do scientists take pictures during an investigation?

A) To show their friends   B) To remember exactly what things looked like   C) For fun   D) To make art

10. What is a science journal used for?

A) To write stories   B) To record observations with drawings and words   C) To do math problems   D) To write letters

Check Your Understanding

Think about these questions to make sure you understand investigation skills.

  • Can you name three tools scientists use to observe living things?
  • Why is it important to record what you observe?
  • What are two things you could measure about a growing plant?
  • How is a good observation different from an opinion?

Next Steps

  • Try observing a plant or animal in your home or yard
  • Start your own science journal with drawings and measurements
  • Continue to the next lesson to learn about organizing data