Reproduction and Growth
- Biology
- Ages 11–14 · Grades 6–8
What you’ll find out
- Animal behaviours such as displays and parental care increase reproductive success.
- Plant structures such as flowers, fruits and seed hooks or wings aid pollination and seed dispersal.
- Growth depends on genes, which set the range, and on environmental factors such as nutrients, water and light.
No sign-up and no real names. In the lesson you check your understanding as you read, and practise until it sticks.
Helping the next generation
Every species must reproduce or it will die out, and animals and plants have evolved behaviours and structures that improve their chances. Many animals attract mates with displays: a peacock fans his dazzling tail, and some birds sing complex songs. Parents often build nests or dens and protect and feed their young. Plants cannot move, so they rely on partners. Colourful, scented flowers attract insects and birds that carry pollen, while tasty fruits tempt animals to eat them and scatter the seeds in their droppings.
What affects growth
How large an organism grows depends on both its genes and its environment. Genes set the possible range: a small breed of dog will never grow as large as a big breed, however much it eats. The environment determines where in that range an organism ends up. Plants need light, water and mineral nutrients, and without enough of them they grow small and weak. Animals need enough nutritious food. Farmers use water and fertilisers to help crops reach their full size.
Curriculum links: NGSS MS-LS1-4 · NGSS MS-LS1-5 · England KS3: Structure and function of living organisms · Cambridge Lower Secondary Stages 7–9: Biology · NCERT Science, Classes 6–8