Why do seeds need a store of food?

Seeds need a store of food because the embryonic plant contained within the seed requires nutrients to germinate and establish itself as a seedling. Here are reasons why seeds have a store of food:

Germination: When a seed germinates, it undergoes metabolic processes that require energy. The stored food provides the necessary energy source for various germination processes, such as cell division, root growth, and shoot emergence. This energy comes from the breakdown of stored macromolecules like starch, proteins, and lipids.

Early Growth and Development: After germination, the seedling relies on the stored food until it can develop enough leaves and roots to photosynthesize and absorb nutrients from the soil. During this critical phase, the stored food sustains the growth and development of the young plant.

Support for Embryo: Inside the seed, the embryo consists of delicate tissues that need protection and nutrition for survival. The stored food acts as a reserve for the embryo, providing the necessary resources to maintain its viability and support its growth.

Harsh Environmental Conditions: Seeds may often encounter harsh environmental conditions, such as drought, extreme temperatures, or nutrient-poor soils. The stored food serves as a survival mechanism, nourishing the embryo and aiding its survival until favorable conditions prevail for germination.

Ecological Advantage: By providing a nutrient reservoir, seeds have a competitive advantage in their natural environment. The stored food enables seedlings to establish quickly, giving them a better chance of outcompeting other plants for resources, such as sunlight, water, and nutrients.

Efficient Dispersal: Some seeds can travel long distances before finding a suitable location for germination. The stored food sustains the embryo during these dispersal events, allowing the seed to remain viable even if it doesn't find a suitable growth site immediately.

In conclusion, seeds contain a store of food to support the initial growth and development of the plant when the seedling is at its most vulnerable stage. This stored food provides essential nutrients and energy during germination and subsequent growth until the seedling can photosynthesize and sustain itself independently.