The multicellular eukaryotes are plants (Plantae), which are one of the ecosystem's important life forms. They are characterized by photosynthetic feeding (except for a few parasitic plants, insectivorous plants) where water, sunlight, minerals, and carbon dioxide are used to generate chemical energy. Secondly, they are immobilized, leading to a stationary life. In a localized area, they can grow widely.
Plants have a well-established vascular system that helps in transporting water and food throughout the body. Their height ranges from a few millimeters (duckweed) to much greater than 90 meters (giant sequoias).
There are plant varieties that are found in various regions of the world; they are present in the dry, cold, underwater, high, low, etc. areas.
There are approx 390, 900 plant species recognized, and more to be discovered in various parts of the world. They all serve the life form and support it in many ways. Both forms of energy consumed by a living organism depend directly or indirectly on the photosynthesis process carried out by green plants.
A type of woody plant which continues its development (perennial). Trees (Plantae) have a single trunk that carries their weight, woody tissues are in the trunk, and a tree's trunk also produces the secondary limbs or branches.
One can define the tree physiologically as a tree's trunk that has dead tissues that help to support the treetop's weight. Within the tissue band, the xylem and phloem are present and help in moving food and water from the roots to other areas of the tree. Inside the cambium, the xylem is present, while the phloem is present outside the tissue.
Every year, the tree grows two annual rings; one is in summer, which is a dense layer known as summerwood, and the second is in spring, which is a thin and vast layer known as springwood types.
Trees represent the largest and fundamental diversity on Earth. The biosphere depends directly or indirectly on the activity of the tree, such as digestion, photosynthesis, recycling, as well as its products (pulp, fruit, leaves, flowers, wood, etc). There are approximately 3 trillion mature trees all over the world.
As they slow and filter rainfall, trees help enhance our water quality.
Trees need water to live, just like humans — and they drink a lot of it. A large tree will absorb 100 gallons of water from the ground in a single day and release it as oxygen and water vapor into the air. Remember that there are many factors that play a role, such as tree size, tree species, humidity, temperature, exposure to the sun, etc.
Plants are divided into their growth habits. Some grow independently while others need support to grow. Based on the growth habits of plants, they are classified as follows-
Herbs- Herbs are short-sized plants with soft and delicate stems without woody tissues and are green in colour. They can be easily and directly uprooted from the soil. Herbs complete their life cycle within 1 or 2 seasons. Usually, herbs have rare branches and mostly are without any branches. Herbs possess many nutritional benefits such as vitamins and minerals. That's why it is recommended to make herbs part of a daily diet to make it healthy and balanced. For example, tomatoes, wheat, grass, etc.
Shrubs- Shrubs are taller than herbs but are shorter than trees. These are medium-sized woody plants with a height ranging between 6 meters and 10 meters. Shrubs are bushy, hard, and have woody stems with multiple branches. Despite having hard stems, shrubs are flexible but still not easily breakable. The lifespan of shrubs depends on their species. For example, rose, tulsi, etc.
Trees- Trees are thick, woody, and tall plants that have hard stems (trunk). The trunk of the tree is the single primary stem. It gives rise to numerous branches that bear leaves, flowers, and fruits. Some trees are branchless like coconut trees, which means they have only one main stem which bears leaves, flowers, and fruits all by itself. Trees live much longer than other plants and some trees live for more than a human being's life. For example, banyan, oak, etc.
Climbers- Climbers are plants that have a very thin, long, and weak stem that cannot stand upright, but they use external aid to grow vertically and hold up their weight. Climbers are those types of plants that use certain structures (tendrils) to grow and climb. Climbers are much more developed than creepers as creepers can't take their own weight. For example, pea plants, money plants, etc.
Creepers- Creepers are very fragile and long plants that drag on the ground. creepers have thin stems that can't stand erect. Their thin stem can't even support all its weight. For example, watermelon, pumpkin, etc.
The difference between creepers and climbers is as follows-
Creepers extend their stem and leave horizontally along with the soil on the ground. Creepers can also bear flowers with fruits on the ground Climbers. The leaves of the creepers cultivate roots that are like fibre. They fix the plant to the ground and supply external aid to grow further.
On the other hand, climbers are plants with a delicate stem that only grows with the help of some external support. Climbers create a twine or hook from its leaves to climb. Some of the climbers make special roots that serve as an attachment to climb around the near objects.
While many characteristics are shared by plants and trees, they are easy to tell apart. Generally, trees are much larger in size than plants. Trees also have only one woody stem and are referred to as a trunk. Plants typically have several roots, but they are readily bendable and somewhat weaker.
Another distinction is that, on the lower parts of their body, trees have few leaves or branches. Plants, although they are closer to the ground, still have leaves. Some plants are composed entirely of leaves as well. Trees have less variety of shapes, ranging from triangular and rounded forms to columnar varieties. In contrast, plants have a broader variety of shapes. These vary from scrambling vines to thickets or clumps.
1. How Do Trees Mitigate Pollution?
The health of humans, animals and plants is negatively affected by high concentrations of harmful gases and particles in our atmosphere. It also causes temperatures to increase, causing climate change to intensify. A third of global emissions are absorbed every year by the world's forests. On the leaves of a tree, particles, odours and pollutant gases such as nitrogen oxides, ammonia and sulphur dioxide settle down. Through their stomata, or 'pores', trees absorb these toxic chemicals, effectively filtering these chemicals from the air. Through trapping heat, and reducing ground-level ozone levels and releasing life-giving oxygen, trees also mitigate the greenhouse gas effect. If our current rate of deforestation continues, it will have a serious impact on the quality of our air.
2. How Do Plants Respire?
In plants, the respiration process involves using the sugars generated during photosynthesis plus oxygen to generate energy for plant growth. Respiration is the opposite of photosynthesis in many respects. Plants produce their food in the natural environment to survive. They use the environment's carbon dioxide to produce sugar and oxygen, which can later be used as an energy source. While photosynthesis only takes place in the leaves and stems, respiration takes place in the leaves, stems, and plant roots. The plants get oxygen from the air through the stomata, as with photosynthesis. In the presence of oxygen, which is called 'aerobic respiration', respiration takes place in the mitochondria of the cell. Two types of respiration occur in plants: dark respiration and photorespiration. In the presence or absence of light, the first kind occurs, while the second occurs solely in the presence of light.
3. What part of a tree is alive?
The outside layers of the tree trunk are the only actual living part of a tree. The cambium that is present in the plant is responsible for producing the new wood and bark. The band of tissue that is outside of the cambium is the phloem. The phloem transports the new substances that are sugars created from photosynthesis, from the peak to the roots. The inner bark, (in older stems is living tissue), possesses the innermost layer of the periderm. The outer bark on older stems consists of the dead tissue on the surface stems with the parts of the outermost periderm and also all the tissues on the outer part of the periderm.
4. What is a stem of a plant?
The part of the plant that is found just above the ground is called the stem of the plant. The stem carries out several functions such as photosynthesis. The stem transports water and minerals from the root and formulates food from leaves to other regions of the plant. Stem gives a solid structure and framework to a plant which later becomes a tree. The area where the leaves appear is known as the node and the area between the nodes is called the internode. In a few plants in the desert areas, such as Opuntia, the stem gets adjusted into thick, fleshy arrangements that hold food and control excessive water loss due to transpiration.
5. What are the different parts present in a flower?
Flowers are the most beautiful and colourful part of a plant. They are also known as the reproductive part of one plant. The parts of the flower are-
Petals: Petals are the colourful part of a flower that is responsible for attracting insects and birds.
Sepals: Sepals are green and leafy parts that lie under petals and protect the flower buds from outside damage.
Stamens: Stamen is the male part of the flower involving another and filament.
Pistil: Pistil is the female part of the flower that consists of stigma, ova, and style.