Growing Plants Growing plants from seeds

Seed Biology Seeds contain all the parts needed to start a new plant Structure - Embryo: a) root b) shoot Food store (starch) – to provide energy Seed coat – to protect the seed

Germination A plant embryo growing into a plant with leaves Food store used up Root grows down, shoot grows up Shoot develops into stem and leaves

Plant Life Cycle 5 stages: - Germination - Plant Growth - Flower Formation - Pollination & Fertilisation - Seed formation & Dispersal

Life cycle stages Germination (early & late) – where seed develops roots and shoots Plant Growth – plant develops stems & leaves Flower formation – growth of flowers Pollination & Fertilisation – pollen carried from one flower to another - pollen joins to egg cell Seed formation & dispersal - fertilisation produces a seed - seed is then taken away from parent plant

Seed Growth/Dormancy Seeds need 3 vital factors to germinate: - water - oxygen - suitable temperature Seeds can stay inactive if the 3 factors aren’t available They are dormant Many stay dormant throughout the winter So, they become active when conditions are best

Photosynthesis Process where green plants make food Change light into chemical energy Takes place in the leaves Occurs after seed’s food store is used up Allows plants to be independent

Growing plants from seeds Sowing – to place seeds in an area where they are likely to grow Seeds need to be spaced out Large seeds are sown by hand Small seeds are mixed with silver sand before sowing Only very small seeds aren’t covered with soil

Pelleted seeds Seed that has been coated in layers of material e.g clay Gives seeds a regular shape – round and smooth Also chemicals can be included amongst the layers: - fungicide – kills fungal spores - pesticide – kills pests in the soil - nutrients – encourage plant growth Pelleted seeds need more water & take longer to germinate BUT produce better, healthier crops

Pre-germination Also known as chitting Makes a seed start to germinate before planting Often done by pre-soaking for a day or two For seeds with hard coats: - coat slit open or ‘nicked’ - coat filed away - rubbed with abrasive paper