Animal groups and different life cycles
This Topic is About...
- I will recognise the different body parts of different groups of animals.
- I will describe and compare the different life cycles of different animals.
- I will use observations to sort animals into different groups.
- I will use a diagram to show how life cycles work.
- I will use a bar chart to answer questions.
- I will use information sources to research and answer questions.
You’re going to be a science explorer!
Key Words
- amphibian
- baby
- caterpillar
- cold-blooded
- hatch
- life cycle
- mammal
- reptile
- tadpole
- warm-blooded
Tap to Learn the Meanings!
- amphibian: An animal that lives part of its life in water and part on land, like frogs.
- baby: A very young animal or human.
- caterpillar: The larva of a butterfly or moth before it becomes a pupa.
- cold-blooded: Animals whose body temperature changes with the environment.
- hatch: When a young animal breaks out of an egg.
- life cycle: The stages an organism goes through from birth to adulthood.
- mammal: An animal that has hair or fur and feeds its babies milk.
- reptile: A cold-blooded animal with scaly skin, like snakes or lizards.
- tadpole: The young stage of a frog, which lives in water and has a tail.
- warm-blooded: Animals that keep a constant body temperature, like birds and mammals.
Great job! You’re learning key words about animals and their life cycles.
Scientists put animals into groups
Animals have many body parts. Some are similar like eyes, some are more unusual like claws or horns.
Some animals are warm-blooded because their bodies make heat inside. Others are cold-blooded. Their bodies are the same temperature as their environment around them.
Scientists group animals into the six groups you can see in the table below.
| Group | |
|---|---|
| mammals (warm-blooded, body hair, they have babies) |
|
| reptiles (cold-blooded, scales, lay eggs) |
|
| fish (cold-blooded, gills, scales, live in water, lay eggs) |
|
| birds (warm-blooded, feathers, lay eggs) |
|
| insects (body in three parts, six legs, lay eggs) |
|
| amphibians (live on land and in water, cold-blooded, lay eggs) |
|
FUN QUESTIONS
1. Look at the animals shown in the table. Point to their different body parts.
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2. Think of another animal for each group.
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– Birds: parrot
– Fish: goldfish
– Mammals: dog
– Reptiles: lizard
3. In which group would you put humans?
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Adult animals and their young
All young animals start life smaller than the adults. Some look like their parents. These polar bears are mammals.
FUN QUESTIONS
4. How is the baby bear similar to the adult bear?
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5. Do they both have the same body parts?
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Some young animals look different to their parents.
Look at these insects. Can you see the young butterfly we call a caterpillar and the adult butterfly?
FUN QUESTION
6. How is the caterpillar different to the adult?
Show answer
Life cycles
All animals grow through different parts of their life. The body of the animal changes. Animals always start life as an egg or a baby. When they are adults, animals can make new eggs or babies.
These changes happen one after another. Changes happen from the start of the animal’s life and go on until the end of its life. We call this the animal’s life cycle.
Look at the life cycle of the chicken from egg to adult. We can follow the arrows from change to change.
Each life cycle diagram is a model which helps us learn.
FUN QUESTION
7. How does the chicken’s body change from chick to adult?
Show answer
As a child you have changed since you were a baby.
The life cycle of a human includes these five stages.
Life cycle of a frog
In humans the baby looks a bit similar to the adult. Young of frogs look very different to the adults.
Frogs lay eggs which hatch into tadpoles. Young tadpoles have a body and a tail. The tadpoles slowly grow legs and lose their tails. They begin to look like small frogs and we call them froglets.
Think like a scientist
Height increases from baby to child
You will need:
a copy of the height bar chart, a ruler or straight edge, a pencil
As each human grows, their height changes. The bar chart shows a child’s height on each birthday from 1 to 10 years old.
Growth in height of a child (1–10 years)
Answer these questions.
- What was the child’s height at 2 years old?
- From age 1 to 2 years, how much did the child’s height increase?
- From age 9 to 10 years, how much did the child’s height increase?
- Why might a doctor or parent be pleased to see this graph?
How am I doing?
Look carefully at the whole graph. What pattern do you notice in the child’s height from 1 to 10 years old?
What does the whole graph tell us about how this child is growing over time?
👀 show answer
1. At 2 years old, the child’s height was about 90 cm.
2. From age 1 to 2 years the height increased from about 75 cm to 90 cm, an increase of about 15 cm.
3. From age 9 to 10 years the height increased from about 145 cm to 150 cm, an increase of about 5 cm.
4. A doctor or parent might be pleased because the graph shows the child is growing steadily each year, which is a sign of healthy growth.
How am I doing?
The pattern on the graph shows that the child keeps getting taller every year. The height increases quickly in the early years and then the increases become smaller as the child gets older.
The whole graph tells us that this child has grown from about 75 cm at age 1 to about 150 cm at age 10, showing continuous, healthy growth over time.