Plants: From Seed To Flower
The Seed
The production of flowers is a fascinating natural process. From a plant’s beginning as a tiny seed, the living organism is able to create its own food and reproduce to continue the cycle of life. Not only do flowering plants provide beautiful landscaping, many flowering plants also provide foods sources, including some fruit. Flowers come in hundreds of varieties, each with a different set of characteristics. Understanding how flowers grow is an important part of biology and science because that knowledge will help us to understand more complex systems later on.
Seeds are baby plants in a dormant, or resting, state. Each seed has a tiny plant embryo inside, surrounded by a thick portion of the seed called the cotyledons. The cotyledons contain stored food, known as endosperm. Their outer seed coat protects them they are ready to germinate, or grow. Proper nutrients are very important for the growth of a healthy baby plant. Nutrient rich soil and water, as well as nutrient supplicants are used by gardeners to ensure that their plants grow up as healthy as possible.
There are many different plant species, but only a couple types of seeds. The two types of seeds are monocots and dicots. The prefix “mono” comes from the Greek word for one, and monocot seeds have one cotyledon. A familiar example of a monocot seed is the corn seed. Dicot seeds come for the Greek word “di,” meaning two. Dicot seeds have two cotyledons, like a bean seed which can be spit into two halves.
Growth
When a seed is planted in dirt, the cotyledons supply food to the plant embryo while the seed collects nutrients from the earth. Seeds germinate best in damp soil because the water helps the seed to absorb nutrients. As the embryo becomes larger, the seed coat splits and a main root comes out of the seed, taking the endosperm with it. The seed coat is shed and the cotyledon becomes the first leaves of the plant. The new plant, known as a seedling, continues to grow below the ground as root hairs extend from the main root. The plant then begins to sprout above the ground and grow more leaves.
When above the ground, a plant needs not only water, but sunlight to continue growing. A plant produces its own food to give it the energy it needs to grow through a process called photosynthesis. Chloroplast cells in the plant’s leaves react with sunlight. The sunlight is stored as energy in a green pigment called chlorophyll. Plants also absorb carbon dioxide from the air through tiny holes in the leaves called stomata. The stored light energy combines with the carbon dioxide to create sugar, which the plant uses as food. A byproduct of the photosynthesis process is oxygen, which we and many creatures on the planet need to breathe. A full-grown plant is now ready to reproduce.
Plant Reproduction
Unlike animal reproduction, which requires mating between a male and female of the species, plants contain both male and female reproductive parts and can reproduce on their own. Pollination occurs when pollen from the male part of the plant, the anther, is transferred to the female part of the flower, or stigma. Grains of pollen attach to the sticky stigma and follow a small tube down the style into the ovary. The pollen fertilizes the ovule which becomes a seed, and the surrounding ovary becomes the fruit.
Since plants can not move on their own, animals, insects or wind help the pollen grains to move from the anther to the stigma. Ninety percent of flowers count on insects for pollination. One example is of a pollinator is the bee. When bees fly from flower to flower, pollen sticks to their legs. As they move to other flowers, they deposit some of the pollen on the stigma, which fertilizes the plant and a seed is created.
Once a plant has fully matured and created its own seeds, the seeds can be planted which will begin the life cycle all over again. While flowers are beautiful to look at, plants provide much more for humanity. Many plants have fruit or leaves that can be harvested for food. However, the most important gift that plants give us is the oxygen created through photosynthesis. Without plants, humans and animals could not survive.
