Year 5 Science: Reproduction in animals
Part of the Year 5 Science reproduction in plants and animals chapter. Chapter overview · whole chapter on one page
Reproduction in animals
Many animals reproduce by sexual reproduction. A male and a female are needed. The male makes sperm and the female makes eggs. When a sperm joins with an egg, this is fertilisation. The fertilised egg then develops into a new young animal.
In a frog, the eggs are fertilised outside the female, in water, as the male releases sperm over the spawn. In a blackbird, the egg is fertilised inside the female, and the egg is laid with a hard shell. In a cat, the young develop inside the mother.
| Animal | Where the young start |
|---|---|
| frog | eggs laid in water, as spawn |
| blackbird | eggs laid in a nest |
| cat | young develop inside the mother |
| butterfly | eggs laid on a leaf |
Key ideas
- Sexual reproduction needs a male and a female.
- The male makes sperm, and the female makes eggs.
- Fertilisation is when a sperm joins with an egg.
- The fertilised egg develops into a new young animal.
Method. Read the table in section 3.3.
- Read the table. The table says the cat’s young develop inside the mother.inside the mother
- Name the animal. So the animal is the cat.cat
- Write the answer. cat
Check. A mammal’s young develop inside the mother. ✓
Method. Read the key idea in section 3.3.
- Read the key idea. The male makes sperm, and the female makes eggs.male makes sperm
- Name it. So the male makes sperm.sperm
- Write the answer. sperm
Check. Sperm and egg join in fertilisation. ✓
Method. Read the description of the frog.
- Read the description. In a frog, the eggs are fertilised outside the female, in water.outside the female
- Decide. So the answer is no.no
- Write the answer. no
Check. The male releases sperm over the spawn in water. ✓
Watch out
Watch out: sperm and eggs are not the young animal. Fertilisation makes one fertilised egg, which then develops into a young animal.
Try it (with your teacher or a grown-up). Look at pictures of animal parents and their young, in a book or on a poster. For each animal, write whether the young develop inside the parent, or start as an egg outside it. Draw one arrow from each parent to its young, and label it. This is a model, so do not touch any real animals.
Exam tip
Grown-up tip. Ask: “Where is the egg fertilised? Where do the young develop?” Keep to the animals in the chapter, and let your child answer in their own words.
Exercise 3C Reproduction in animals
Method. Read the table in section 3.3.
- Read the table. The frog lays its eggs in water, as spawn.in water
- Name the animal. So the animal is the frog.frog
- Write the answer. frog
Check. Frog spawn is fertilised in the water. ✓
Method. Read the table in section 3.3.
- Read the table. The cat’s young develop inside the mother.inside the mother
- Name the animal. So the animal is the cat.cat
- Write the answer. cat
Check. Most mammals develop their young inside the mother. ✓
Method. Read the key idea in section 3.3.
- Read the key idea. The male makes sperm, and the female makes eggs.male makes sperm
- Name it. So the word is sperm.sperm
- Write the answer. sperm
Check. Sperm and eggs are the reproductive cells. ✓
Method. Read the key idea in section 3.3.
- Read the key idea. When a sperm joins with an egg, this is fertilisation.joins with an egg
- Name it. So the word is fertilisation.fertilisation
- Write the answer. fertilisation
Check. The fertilised egg then develops into a young animal. ✓
Method. Read the key idea in section 3.3.
- Read the key idea. Sexual reproduction needs a male and a female.a male and a female
- Fill the gap. So the missing word is female.female
- Write the answer. female
Check. The female makes eggs. ✓
Method. Read the description in section 3.3.
- Read the description. In a blackbird, the egg is fertilised inside the female, and then laid with a hard shell.inside the female
- Decide. So the answer is yes.yes
- Write the answer. yes
Check. The hard shell is added after fertilisation. ✓
Method. Read the description in section 3.3.
- Read the description. In a frog the eggs are fertilised outside the female, in water.outside the female
- Decide. So the answer is no.no
- Write the answer. no
Check. The male releases sperm over the spawn. ✓
Method. Read the table, and find the rows that say the young start inside.
- Read the rows. The cat’s young develop inside the mother. The blackbird’s egg is fertilised inside the mother.two rows
- Name the animals. So the two animals are the cat and the blackbird.cat and blackbird
- Write the answer. cat and blackbird
Check. The table gives the frog and butterfly as the other two. ✓
Method. Read the table.
- Read the rows. The frog lays spawn in water, and the butterfly lays its eggs on a leaf.outside
- Name the animals. So the two animals are the frog and the butterfly.frog and butterfly
- Write the answer. frog and butterfly
Check. Both lay their eggs outside the body of the parent. ✓
Method. Think about what the joined cell is called.
- Think about the join. When a sperm joins with an egg, the cell formed is called a fertilised egg.fertilised egg
- Name the cell. So the answer is fertilised egg.fertilised egg
- Write the answer. fertilised egg
Check. The fertilised egg develops into a young animal. ✓
Method. Think about the start of a new animal.
- Think about the egg. An egg alone does not develop into a young animal.alone
- Write the reason. Fertilisation makes the fertilised egg, which develops into the young.develops into the young
- Write the answer. Accept any sentence that says fertilisation is needed to make the fertilised egg, which then develops into a young animal.
Check. Fertilisation is the start of a new animal. ✓