What Is A Plant?
Plants have more similarities to human beings than one might think. For instance, like us, plants have veins that transport nutrients and sap, which is similar to blood, to vital parts of their bodies. They also possess the ability to breathe, and their lives are regulated by hormones and a basic nervous system. Additionally, plants can reproduce themselves.
Interestingly, human blood shares a striking similarity with chlorophyll, a green pigment found in all green plants that absorbs light to generate energy for photosynthesis. However, blood contains iron while chlorophyll contains magnesium, as noted in a medical research paper.
For further evidence of our resemblance to plants, scientists have found that over 60% of human DNA is identical to the DNA of a banana. A research article in the Journal of Biological Databases and Curation provides more information on this topic.
Given these similarities, let’s now explore the different parts of a plant.
Plants have two primary types of roots: branching roots, also known as adventitious roots, and tap roots.
Branching roots are large roots that can be seen when a plant is removed from its pot or dug up from the ground. They serve to anchor the plant to the ground and typically spread out over a wide area.
On the other hand, tap roots are commonly found in plants such as carrots and parsnips. These roots are used by the plant to store starches that will be utilized as fuel during the following season’s flowering.
It may come as a surprise that none of the plant’s roots take in water. Instead, the uptake of water and dissolved nutrients is carried out by microscopic root hairs located around the tips of the main roots. Essentially, plants cannot consume solid food, but they absorb a mineral-rich liquid, similar to a vacuum created by the evaporation of water from their leaves.
To put it simply, what goes in as liquid through the root hairs comes out as water vapor through the leaves.
The stem of a plant is considered its skeleton, providing structural support to prevent the plant from falling over and holding its leaves, flowers, and fruit in the best possible position.
In trees and other long-living plants, the stem adapts and forms solid structures (wood), which provides an even stronger framework to carry the weight of the plant.
Stems function like veins, containing a specialized tissue called xylem that transports water and dissolved minerals throughout the plant. The phloem, which carries starches and other essential nutrients, moves up from the stem to the areas where they are needed.
Leaves can be thought of as a plant’s power plant, using solar panels to carry out photosynthesis. Chlorophyll, the green pigment present in leaves, absorbs energy from the sun, which is used to convert carbon dioxide from the air and water and nutrients from the soil into starches.
Plants can store starch in underground reservoirs, such as in the case of carrots and potatoes. As a result of photosynthesis, plants release oxygen, which is essential for both the planet and our survival.
Flowers And Seeds
Flowers and seeds play a crucial role in the reproduction of a plant. The male pollen from one flower fertilizes the female part of another flower of the same species, resulting in the production of a fruit or a pod that will eventually ripen and release seeds for the next generation. For example, when an apple falls from a tree and its seeds are scattered on the ground, new apple trees can grow from those seeds.
Each flower has different parts. The petals act like waving flags to attract pollinating insects. The stamen is the male reproductive part of the flower, consisting of a filament stem and a pollen-loaded anther. The pistil is the female reproductive part, located centrally with a swollen base containing the ovary, a stem, and a pollen receptive tip called the stigma.
Seeds are formed in the ovary and can become either fruit or seed pods. Just like young birds leaving the nest, seeds must also be dispersed to prevent competition for vital nutrients, water, and light with the parent plant. Seeds have evolved various ways of travelling to new locations for successful germination.
Methods of Seed Dispersal
Plants have developed various methods to disperse their seeds to ensure their offspring can grow in suitable conditions. Here are some common methods:
Animals, including humans, can help disperse seeds in different ways. Birds, for example, eat fruits that contain seeds and drop them away from the parent plant through their droppings. Some seeds have hooks that catch onto animal fur or clothing, like burdock.
Some plants rely on water to disperse their seeds. Coconuts, for example, can float on water and be carried by ocean currents to new locations. Waterlilies and mangrove trees also use water to transport their seeds.
Some plants have seedpods that dry out and burst open, propelling the seeds in all directions. Pea and bean plants use this method.
Certain species of pine trees require heat to open their cones and release their seeds.
Types of Flowers
Most flowers have both male and female parts, but some plants have separate male and female flowers on the same plant (monoecious plants), like zucchini (courgettes). Others, like hollies, have male and female flowers on separate plants (dioecious plants).