Chapter 2 Notes: Diversity in the Living World

Biodiversity means the variety of plants and animals found in a particular region. Every plant and animal has a unique role — trees give shelter to birds, animals spread seeds, and so on. This shows that all living things are interdependent.

Plants are grouped based on their height, stem type, and branching pattern:

• Herbs: Small plants with soft, green stems (e.g., tomato, mint).
• Shrubs: Medium-sized plants with hard but thin woody stems that branch close to the ground (e.g., rose, hibiscus).
• Trees: Tall plants with thick, hard, woody stems that branch high up (e.g., mango, neem).
• Climbers need support to grow upward; Creepers grow along the ground.

Veins are the thin lines on leaves, and their pattern is called venation. There are two types:

• Reticulate venation: Net-like pattern (e.g., hibiscus, mango).
• Parallel venation: Veins run parallel to each other (e.g., grass, banana).

Roots also have two types:

• Taproot: One main thick root with small side roots (e.g., mustard, hibiscus).
• Fibrous roots: A bunch of thin, similar-sized roots from the stem base (e.g., grass, wheat).

Seeds can be divided based on the number of cotyledons (seed leaves inside the seed):

• Dicotyledons (Dicots): Seeds split into two parts (e.g., chickpea, mustard). Dicots have reticulate venation and taproots.
• Monocotyledons (Monocots): Seeds have only one thin cotyledon (e.g., maize, wheat). Monocots have parallel venation and fibrous roots.

Animals can be grouped in many ways — by what they eat, where they live, or how they move. For movement, different animals use different body parts: fish use fins, birds use wings, and goats use legs. Animals can fly, run, crawl, hop, or swim depending on their body structure and habitat.

The place where a plant or animal lives is its habitat, which provides food, water, air, and shelter. Plants and animals develop adaptations — special features to survive in their habitat. For example, cactus stores water in thick stems for hot deserts, deodar trees have conical shapes to shed snow in cold mountains, and desert camels have wide hooves to walk on sand.

When habitats are damaged by human activities like deforestation, plants and animals lose their homes, food, and resources — leading to loss of biodiversity. India has launched projects like Project Tiger (1973) and the Cheetah Reintroduction Project (2022) to protect endangered species. Sacred groves are traditional community-protected forest patches that preserve local biodiversity.