Nutrition in Plants and Animals: Understanding the Basics

Nutrition is the process by which living organisms obtain and utilize food to sustain life and carry out essential functions. In Class 7 science curriculum, one of the fundamental topics covered is nutrition in both plants and animals. Understanding how plants and animals obtain their nutrients is crucial for comprehending the processes that support life on Earth.

Nutrition in Plants:

Plants are autotrophic organisms capable of synthesizing their own food through the process of photosynthesis. Here's an overview of nutrition in plants:

1. Photosynthesis: Photosynthesis is the biochemical process by which green plants, algae, and some bacteria convert light energy, water, and carbon dioxide into glucose and oxygen using chlorophyll pigment in the presence of sunlight. The chemical equation for photosynthesis is: 6 CO2 + 6 H2O + Light energy → C6H12O6 + 6 O2
2. Role of Chlorophyll: Chlorophyll, the green pigment present in chloroplasts, captures light energy required for photosynthesis. Chloroplasts are the specialized organelles where photosynthesis takes place in plant cells.
3. Absorption of Water and Minerals: Apart from photosynthesis, plants also absorb water and minerals from the soil through their roots. Water is essential for maintaining turgidity and transporting nutrients within the plant.
4. Transport of Nutrients: Once synthesized, glucose and other nutrients produced during photosynthesis are transported to different parts of the plant through the vascular system, including xylem and phloem.

Nutrition in Animals:

Animals are heterotrophic organisms that rely on external sources for obtaining their nutrients. Here's an overview of nutrition in animals:

1. Ingestion: Animals ingest food through their mouth, where it undergoes mechanical and chemical digestion processes.
2. Digestion: Digestion begins in the mouth, where food is broken down into smaller pieces by chewing and mixed with saliva containing enzymes like amylase. It continues in the stomach, where gastric juices containing hydrochloric acid and pepsin further break down food. The process of digestion is completed in the small intestine, where nutrients are absorbed into the bloodstream.
3. Absorption: Nutrients such as glucose, amino acids, fatty acids, vitamins, and minerals are absorbed from the small intestine into the bloodstream through the villi, finger-like projections lining the intestinal walls.
4. Assimilation and Utilization: Once absorbed, nutrients are assimilated by cells and tissues throughout the body for energy production, growth, repair, and maintenance of bodily functions.
5. Egestion: Undigested food and waste products are eliminated from the body through the process of egestion, primarily through the anus.

Key Differences Between Plant and Animal Nutrition:

1. Plants synthesize their own food through photosynthesis, while animals rely on external food sources.
2. Plants absorb water and minerals from the soil, while animals ingest food through their mouth.
3. Digestive systems of animals involve specialized organs such as the mouth, stomach, and intestines for digestion, absorption, and egestion.

In conclusion, nutrition plays a vital role in sustaining life processes in both plants and animals in class 7 science topic. Understanding the mechanisms of nutrition in plants and animals is essential for appreciating the complexities of the natural world and the interdependence of living organisms within ecosystems.

This essay provides a comprehensive overview of nutrition in plants and animals, covering key concepts and processes within the specified word limit.