NARAYANKAR NOTES

  Chapter 13: Organisms and Populations —  This chapter explains how organisms live in their surroundings, how they adjust to environmental conditions, how populations grow, and how different species interact with one another . 1. Ecology The natural world contains a huge variety of living organisms. To understand this living world, scientists study different levels of organization : Macromolecules → Cells → Tissues → Organs → Organism → Population → Community → Ecosystem → Biome What is Ecology? Ecology is the study of: interactions between organisms, and interactions between organisms and their physical or abiotic environment . The term ecology was first used by Reiter , while E. Haeckel gave proper meaning and importance to the concept. organisms and population tb 2. Ecological Hierarchy The chapter mainly describes four ecological levels: Organism → Population → Community → Biome Organism An individual living being. Example: One tiger, one mango tree, one human. Popu...

 Below is a one-shot HSC Board lecture for Chapter 14 – Ecosystems and Energy Flow , based on your uploaded textbook. It covers the major definitions, processes, diagrams, comparisons, and points that are most useful for board preparation. Ecosystem and energy flow tb CHAPTER 14 — ECOSYSTEMS AND ENERGY FLOW HSC BOARD ONE-SHOT LECTURE 1. Ecosystem An ecosystem is a self-regulatory and self-sustaining structural and functional unit of nature containing both biotic and abiotic components . The term ecosystem was coined by A. G. Tansley in 1935 . Think of an ecosystem as: Living organisms + non-living environment + interaction between them Examples: Pond Forest Grassland Desert River Ocean The entire biosphere can also be considered one global ecosystem . Types of ecosystems Terrestrial ecosystems Forest Grassland Desert Aquatic ecosystems Lakes Rivers Wetlands Estuaries Oceans Another classification: Natural ecosystem: self-sustainable and generally does not need regular human...

The moon was a silver coin in the night sky. She ran as fast as a cheetah. His words were daggers in my heart. The baby slept like a log. Time is a thief that steals our precious moments. Her smile was as bright as the sun. The classroom was a zoo during the break. He fought like a lion in the competition. Her eyes were sparkling diamonds. The old man was as wise as an owl. Life is a journey filled with unexpected turns. The water was as clear as crystal. My brother is a walking encyclopedia. The clouds looked like balls of cotton in the sky. His heart was a block of ice. She sings like a nightingale. The city is a jungle of concrete. He was as busy as a bee all morning. The stars were tiny lamps hanging in the sky. The child clung to his mother like a koala to a tree. Her voice was music to my ears. The boy was as hungry as a wolf. The wind was a wild beast roaring through the trees. The snow covered the ground like a white blanket. Books are windows to the world. His hands were as co...

🌿 PLANT WATER RELATION Recall...🤔🤔 1.Which are the various parts of plant body? 2. What are the functions of various parts of plant body? 3. Which plant tissues are involved in transport of water and minerals? Plants obtain a variety of substances from their surroundings: Water, Minerals, Nutrients, Gases such as O₂ and CO₂ 🤔Why is water so important? Water is considered the “Elixir of Life”. The productivity of plants is greatly affected  by the availability of water. If sufficient water  is not available, several essential processes  of the plant are affected mainly photosynthesis. Water constitutes approximately 90–95% of most plant cells and tissues. It helps cells to: maintain their turgidity maintain their shape carry out various biochemical activities   How does water move from the soil → roots → stem → leaves, even against gravity? PROPERTIES OF WATER 1. It is in the liquid form at room temperature and is the best solvent for most of the solut...