• Question: How does the plant cycle work

    Asked by anon-349295 on 6 Mar 2023. This question was also asked by anon-349299.
    • Photo: Phil Howell

      Phil Howell answered on 6 Mar 2023:

      It usually starts with a seed. Seeds contain all the food plants need to survive in the beginning, so when seeds start to grow (we call this germination) the stored food in the seed gets digested and tunred into the energy and materials the seedling needs to grow the first roots and shoots. Once the shoots reach the surface they use the energy in sunlight to drive more growth, getting taller and growing more leaves and roots to support the plant. Once it is big and strong enough, if it is the right time of year the plant puts more energy into producing flowers – which can be pretty and coloured and scented, but don’t have to be – so that they can reproduce through the production of new seeds. Of course life is very complicated, not all plants produce flowers, and not all plants produce seeds. Some plants die soon after producing seeds, others last for many years producing seeds over several cycles. Some flower and produce seed very quickly, others may take years.

    • Photo: Laura Vickers

      Laura Vickers answered on 9 Mar 2023:

      A plant cycle begins with a baby plant contained in a seed. That once it has the right conditions, it will germinate. This maybe moisture and a good temperature. Each species varies with its exact requirements to germinate but generally good temperature (not too hot and not cold) and moisture are the main requirements.

      The plant emerges from the seed and produces a few leaves to start photosynthesising. This is the process of converting light energy to chemical energy: food such as glucose.

      They also produce roots to get water, for photosynthesis and other reactions, and minerals from the soil to make proteins and other molecules.

      All of these molecules are used to make new cells and tissues and grow. The plant then can do two things. 1) Produce a flower and sexually reproduce creating a seed, that mixes the genetics from two plants. This is from a pollen grain being brought to the plant from another plant, via either a bee (insect pollinator) or the wind. This fertilises the ovule (like an egg) and produces seed. This seed falls to the floor and germinates to repeat the cycle. Sometimes seeds are in fruit and carried away by animals somewhere else, or they can be blown away by the wind.

      2) Or they can genetically clone themselves in what we call asexual reproduction. This can be through runners in the soil that sprout up a new plant (think of a strawberry plant here). Or mini plants on the edges of leave that drop off into the soil to create a new plant (plantlets). If you’ve ever grown a spider plant in your house they often do this.

      Once the plant has reproduced (and it may have many years doing this or only a few weeks, think of the life of an oak tree compared to a annual needing plant), eventually the plant will reach the end of its life and die.