CBSE _ NCERT Class-7th Science Chapter: Fibre to Fabric Why a cotton garment cannot keep us as warm in winter? Cotton clothes are thin and do not have spaces in which air can be trapped. thus Cotton clothes do not prevents heat coming out of our body. What is a fibre? A fibre is a long strong thread, which is obtained from natural sources or man made sources. Fibres are classified into two types on the basis of their sources. Plant fibres and animal fibres and synthetic fibres . The fibres, which are obtained from plants and animals are called natural fibres e.g., jute and wool. Animal fibres are obtained from animals, e.g., silk and wool. Those fibres which are made by the human –beings are known as Man-made or Synthetic Fibres, e.g., Rayon. Match the following: 1. Scouring-- > Cleaning sheared skin 2. Mulberry leaves -> Food of silkworm 3. Yak -> ...