Following fertilisation, the ovule will produce a structure called a seed (in certain plants, this may be contained within a fruit)

• The embryo in a seed will initially develop within the parental plant until growth is halted (dormancy) – the seed is then dispersed and subsequently germinates to form a new plant 
  

Seed Structure

A typical plant seed will possess the following features:

• An outer seed coat (testa) that protects the embryonic plant – the coat contains a small pore (micropyle) to allow for the passage of water
  

• The interior consists of a embryonic leaf (cotyledon) that contains the food reserves, as well as an embryonic root (radicle) and shoot (plumule / epicotyl) 

Structure of a Seed

Seed Dispersal

Seeds are typically dispersed away from the parental plant, to reduce competition for resources between parent and offspring

• There are a variety of seed dispersal mechanisms, including wind, water and animals – seed structure may vary according to the dispersal method employed
  

Most seeds do not germinate immediately and instead require specific conditions to damage the seed coat and break a state of dormancy

• Such conditions may include exposure to heat (fire), pH changes (due to animal digestion) or washing to remove inhibitors preventing germination 
  

Seed Germination

Germination begins with the absorption of water, which metabolically activates the seed by causing gibberellin to be produced

• Gibberellin is a plant hormone which triggers the synthesis of enzymes capable of digesting the food reserves within the cotyledon
  

• The sugars produced are either hydrolysed to produce energy (via cell respiration), or polymerised to produce vital cell components (biosynthesis) 
  

Once the seed is metabolically activated, germination proceeds according to the following stages:

• The seed coat (testa) ruptures and the embryonic root (radicle) grows into the ground to extract key nutrients and minerals
  

• The cotyledon emerges and produces the growing shoot’s first leaves (allowing photosynthesis to begin)
  

• The growing plant continues to develop, forming distinctive roots, stems, leaves (and potentially flowers)
  

Germination Timelapse