Diversity in the Living World
The world around us is full of a vast variety of living things. When we observe nature, we notice different types of plants and animals, each with unique characteristics. For instance, birds have their own distinct chirps, which is a clear example of the variety present in nature. Observing and understanding this variety is the objective of studying the living world.
Diversity in Plants and Animals Around Us
Nature is rich in various forms of plants and animals. When we explore a park or a forest, we can observe many differences:
- Plants vary in their smells, forms, and structures. We see grasses, bushes, and large trees.
- Animals include birds, butterflies, and monkeys, each exhibiting different behaviors and appearances. Birds chirp uniquely, butterflies move from flower to flower, and monkeys jump between trees.
These observations highlight the wide range of features in living organisms. Plants, for example, show variety in:
- Their height (tall or short) and the nature of their stem (hard or soft).
- The shapes of their leaves and how these leaves are arranged on the stem or branches.
- The colour, shape, and scent of their flowers.
Animals also display significant diversity:
- They live in different places, such as on land, on trees, or in water. For example, birds live on trees, fish live in water, and frogs can live both on land and in water.
- They consume a diverse range of foods.
- They exhibit a variety of movements.
The variety of plants and animals found in a particular region is known as biodiversity. Each part of this biodiversity plays an important role. For example, trees provide food and shelter to animals, and animals help spread seeds by eating fruits. This demonstrates that plants and animals are dependent on each other for survival.
How to Group Plants and Animals?
To better understand and study the vast variety of plants and animals, we can group them based on their similarities and differences. Grouping helps us to organise our knowledge of the living world.
Different criteria can be used for grouping. For plants, some might consider height, while others might focus on the presence or absence of flowers. For animals, grouping might be based on their eating habits, where they live, their colour, or how they move. The importance of grouping is that it simplifies the understanding and study of diverse organisms.
How to group plants?
Plants show many variations in their stems, leaves, and flowers. These features can be used to group them effectively.
One common way to group plants is based on their height, stem type, and branching patterns:
- Herbs: These are typically small plants with soft, green, and tender stems. Their branches usually arise close to the ground. An example is a tomato plant.
- Shrubs: These plants are usually medium in height, not as tall as trees. They have many brown, woody stems that start branching very close to the ground. Their stems are hard but not as thick as those of trees. A rose plant is an example of a shrub.
- Trees: These are tall plants with a single, thick, hard, brown, woody stem (trunk). Their branches typically arise higher up on the stem. A mango tree is an example.
- Climbers: These plants have weak stems and require support to climb and grow upwards.
- Creepers: These plants also have weak stems but grow along the ground instead of climbing.
Another way to group plants is by observing the venation in their leaves. Venation refers to the pattern of veins on a leaf.
- Reticulate venation: In this pattern, the veins form a net-like network on both sides of a thick middle vein. Leaves of hibiscus plants show reticulate venation.
- Parallel venation: In this pattern, the veins run parallel to each other. Leaves of banana plants and grasses exhibit parallel venation.
The roots of plants also show diversity, allowing for another grouping method:
- Taproot: This root system consists of one main, thick root from which smaller side roots arise. Mustard plants and hibiscus plants have taproots.
- Fibrous roots: This system consists of a bunch of similar-sized thin roots that arise from the base of the stem. Common grass plants and lemongrass have fibrous roots.
There is a general relation between leaf venation and root type:
- Plants with reticulate venation typically have taproots. Examples include sadabahar and chickpea.
- Plants with parallel venation generally have fibrous roots. Examples include lemongrass and wheat.
Finally, plants can be grouped based on their seeds:
- A cotyledon is a part of the embryo within the seed of a plant.
- Dicotyledons (dicots): These are plants whose seeds can be split into two parts, meaning they have two cotyledons. Chickpea seeds are dicots.
- Monocotyledons (monocots): These are plants whose seeds have a single cotyledon. Maize seeds are monocots.
There is also a clear relation among the number of cotyledons, leaf venation, and root types:
- Dicot plants typically have reticulate venation in their leaves and a taproot system.
- Monocot plants typically have parallel venation in their leaves and a fibrous root system.
How to group animals?
Animals are incredibly diverse in their features. We can group them based on various characteristics, just like plants. One significant way to group animals is by their types of movement and the body parts they use for movement.
- Animals exhibit different movements like flying, running, crawling, walking, hopping, or jumping.
- They use specific body parts for movement, such as wings (for flying), legs (for walking, running, jumping), or fins (for swimming).
Beyond movement, animals can also be grouped based on their shape, size, structure, and colour. Grouping animals helps in understanding their vast diversity and the roles they play in different environments.
Plants and Animals in Different Surroundings
The characteristics of plants and animals, including their movement, are often linked to their surroundings. For example, fish have streamlined bodies and fins, which are specialized features that help them move efficiently in water. Goats, living in grassy areas, use their legs for movement.
The special features that enable plants and animals to survive in a particular region are called adaptations. These adaptations allow organisms to thrive under specific environmental conditions.
Here are some examples of adaptations:
- Desert Plants (e.g., Cactus): Deserts have very little water and experience extreme temperature changes (hot days, cold nights). Cactus plants have thick and fleshy stems that store water, helping them tolerate the hot conditions.
- Mountain Trees (e.g., Deodar): Mountains in extremely cold regions often experience heavy snowfall. Deodar trees are conical in shape with flexible and sloping branches. This adaptation allows snow to slide off easily, preventing damage to the tree.
- Camels: Camels show different adaptations depending on whether they live in hot or cold deserts.
- Hot Desert Camels (e.g., Rajasthan): They have long legs with wide hooves, which prevent them from sinking into the sand. They store food in one hump and excrete small amounts of urine, dry dung, and do not sweat, all to conserve water.
- Cold Desert Camels (e.g., Ladakh): They have comparatively shorter legs, which are better suited for mountainous regions. They have two humps for food storage, which can shrink in winter when food is scarce. They also grow long hair from head to neck to survive cold winters.
- Rhododendrons: These flowering plants show variations even within mountainous regions. In windy mountain tops (like Nilgiris), they might be shorter with smaller leaves. In other mountain areas (like Sikkim), they might grow taller, adapting to local conditions.
- Fish: Their streamlined body shape is an adaptation that reduces resistance and helps them swim efficiently in water.
The specific place where plants and animals live is called their habitat. A habitat provides an organism with all its essential needs for survival, including food, water, air, and shelter. Many different types of plants and animals can share the same habitat. The unique conditions of a habitat play a crucial role in shaping the biodiversity of that region.
Based on their habitats, plants and animals can be grouped:
- Terrestrial habitats: These are habitats on land. Examples include forests, deserts, grasslands, and mountains. Plants and animals living here are called terrestrial organisms.
- Aquatic habitats: These are habitats in water. Examples include ponds, lakes, rivers, and oceans. Plants and animals living here are called aquatic organisms.
- Amphibians: Some animals, like frogs, can live both in water and on land. These are known as amphibians.
Damage to habitats can have severe consequences. When habitats are destroyed or disturbed, plants and animals lose their homes, food sources, and other vital resources. This directly leads to the loss of biodiversity. For instance, the populations of the Bengal Tiger, Cheetah, and Great Indian Bustard in India have declined due to human activities damaging their natural habitats.
Recognizing this threat, governments and communities have initiated various conservation efforts:
- 'Project Tiger' was started in 1973 to protect the declining population of the Bengal Tiger.
- The 'Cheetah Reintroduction Project' was initiated in 2022 to restore the Cheetah population.
- Habitats of the Great Indian Bustards have been declared as protected areas in states like Gujarat, Rajasthan, and Maharashtra.
Sacred groves are traditionally protected forests found across India. These are undisturbed patches of forest, varying in size, that are home to diverse plants and animals, including many medicinal plants. Local communities protect these groves, prohibiting harm to animals or cutting of trees. This makes sacred groves a valuable, community-protected treasure of biodiversity.
It is essential to protect biodiversity to ensure that our planet remains vibrant with life, allowing all plants and animals to survive and thrive.
Keywords
- Adaptation
- Amphibians
- Aquatic
- Biodiversity
- Cotyledon
- Dicot plants
- Fibrous root
- Habitat
- Herbs
- Monocot plants
- Parallel venation
- Reticulate venation
- Sacred groves
- Shrubs
- Taproot
- Terrestrial
- Tree
- Venation