Plant and Animal Nutrition

Nutrition in Plants

• Plants are autotrophs, producing their own food through photosynthesis.
• Photosynthesis uses chlorophyll, sunlight, carbon dioxide, and water to create carbohydrates (food) and oxygen.
• Heterotrophs, like animals and some plants, rely on others for nutrition since they cannot produce their own food.
• Parasitic plants, such as Cuscuta, get their nutrition from other plants (hosts).
• Saprophytes acquire nutrients from dead and decaying organic matter.
• Nutrients, including carbohydrates, proteins, fats, vitamins, and minerals, are vital food components.
• Rhizobium bacteria in leguminous plant root nodules convert atmospheric nitrogen into usable forms for the plant.

Nutrition in Animals

• Animals are heterotrophic and get food from plants or other animals.
• Nutrition involves ingestion, digestion, absorption, assimilation, and egestion.
• Digestion simplifies complex food into absorbable forms.
• In humans, digestion starts in the mouth where saliva breaks down starch into sugars.
• The esophagus transports food to the stomach.
• The stomach mixes food with digestive juices like hydrochloric acid and protein-digesting enzymes.
• The small intestine is the primary site for nutrient absorption.
• Bile, from the liver, supports fat digestion, while pancreatic juice from the pancreas contains enzymes for digesting carbohydrates, fats, and proteins.
• Villi in the small intestine increase the surface area for absorption.
• The large intestine absorbs water and salts from undigested food.
• Undigested waste is expelled through the anus.
• Ruminants, such as cows, have a rumen where food is partially digested and then regurgitated as cud for further chewing.

Fibre to Fabric

• Fibres can be natural or synthetic.
• Natural fibres originate from plants (cotton, jute) or animals (wool, silk).
• Synthetic fibres, like nylon and polyester, are man-made.
• Wool is sourced from sheep, goats, yaks, and other animals.
• Silk is derived from silkworms.
• Rearing includes feeding, sheltering, and breeding animals such as sheep.
• Shearing refers to removing fleece from sheep.
• Scouring cleans sheared wool to eliminate grease, dust, and dirt.
• Sorting separates wool based on different textures.
• Sericulture is silk production, involving silkworm rearing to get silk.
• Silkworms consume mulberry leaves.
• Silkworms create cocoons made of silk fibres.
• Silk fibres are extracted from cocoons through reeling.

Heat

• Heat is energy that creates a sensation of warmth.
• Temperature quantifies the hotness or coldness of an object.
• Thermometers measure temperature.
• Clinical thermometers measure body temperature.
• Laboratory thermometers measure the temperature of objects.
• Normal human body temperature is about 37°C.
• Heat flows from a hotter object to a colder object.
• Conduction transfers heat through a material without material movement, mainly in solids.
• Convection transfers heat via fluid (liquid or gas) movement.
• Radiation transfers heat through electromagnetic waves without needing a medium.
• Dark-colored objects absorb more heat than light-colored ones.
• Woolen clothes keep us warm in winter because wool traps air, which is a poor heat conductor.

Acids, Bases and Salts

• Acids taste sour and turn blue litmus paper red.
• Bases taste bitter, feel soapy, and turn red litmus paper blue.
• Neutralisation is an acid-base reaction that produces salt and water.
• Indicators change color in acidic and basic solutions (e.g., litmus, turmeric, china rose).
• Common acids include hydrochloric acid, sulfuric acid, and nitric acid.
• Common bases include sodium hydroxide, potassium hydroxide, and calcium hydroxide.
• Salts form through acid-base neutralisation.
• Acid rain contains excessive acids, harming buildings, soil, and aquatic ecosystems.

Physical and Chemical Changes

• Physical changes alter a substance's physical properties without changing its composition (e.g., melting ice, boiling water).
• Chemical changes create new substances and are usually irreversible (e.g., burning wood, rusting iron).
• Rusting iron requires oxygen and water.
• Crystallization purifies solid substances from a solution.
• Galvanization protects iron from rusting by coating it in zinc.

Weather, Climate and Adaptations of Animals to Climate

• Weather reflects daily atmospheric conditions regarding temperature, humidity, rainfall, wind speed, etc.
• Climate describes average weather patterns over a long time (e.g., 25 years).
• Temperature, humidity, and rainfall are key climate determinants.
• Polar regions have extremely cold climates, whereas tropical regions have hot and humid climates.
• Polar bears have thick fur and fat layers, adapting them to polar regions.
• Penguins huddle to stay warm.
• Tropical rainforests are in regions with hot, humid climates and plentiful rainfall.
• Tropical rainforest animals have adaptations like camouflage and specialized diets.

Winds, Storms and Cyclones

• Wind is moving air, driven by air pressure differences.
• High-speed winds and air pressure variations can trigger storms and cyclones.
• Cyclones are large air masses rotating around a low-pressure center.
• An anemometer measures wind speed.
• A cyclone's eye is a calm area at its center.
• Cyclones can cause massive destruction from strong winds, heavy rain, and storm surges.
• Storm surges raise sea levels abnormally during storms.
• Weather forecasting aids in predicting and preparing for storms and cyclones.

Soil

• Soil, the Earth's top layer, supports plant growth.
• Soil forms through weathering, breaking rocks into smaller particles.
• Soil profiles have different layers or horizons (A, B, C) with unique compositions and features.
• Soil comprises minerals, organic matter, air, and water.
• Soil types include sandy, clayey, and loamy soil.
• Sandy soil is well-aerated but retains little water.
• Clayey soil retains much water but is poorly aerated.
• Loamy soil, a sand, clay, and silt mix, is best for plant growth.
• Soil erosion is the removal of topsoil by wind, water, or human activity.
• Soil conservation through afforestation (planting trees), terracing, and contour plowing prevents soil erosion.

Respiration in Organisms

• Respiration breaks down food to release energy.
• Aerobic respiration uses oxygen to break down glucose into carbon dioxide, water, and energy.
• Anaerobic respiration occurs without oxygen and produces less energy.
• Breathing involves inhaling oxygen-rich air and exhaling carbon dioxide-rich air.
• Humans breathe through their nose and lungs.
• The diaphragm is a muscle that facilitates breathing.
• Fish breathe through gills, extracting oxygen from water.
• Earthworms breathe through their skin.
• Plants respire via stomata on their leaves.

Transportation in Animals and Plants

• Transportation moves substances within the body.
• In animals, the circulatory system transports nutrients, oxygen, and waste.
• The heart pumps blood through blood vessels.
• Arteries carry oxygen-rich blood from the heart.
• Veins carry carbon dioxide-rich blood back to the heart.
• Capillaries are tiny vessels facilitating substance exchange between blood and tissues.
• Blood consists of plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets.
• RBCs carry oxygen, WBCs fight infection, and platelets aid blood clotting.
• In plants, xylem transports water and minerals from roots.
• Phloem transports food from leaves.
• Transpiration, water loss from leaves, aids water movement in the xylem.

Reproduction in Plants

• Reproduction is how organisms create new individuals.
• Asexual reproduction involves one parent, with offspring genetically identical (e.g., budding, fragmentation, spore formation, vegetative propagation).
• Sexual reproduction involves two parents, with offspring genetically different.
• Flowers are plant reproductive organs.
• The stamen (anther and filament) is the flower's male part.
• The pistil (stigma, style, and ovary) is the flower's female part.
• Pollination transfers pollen from anther to stigma.
• Self-pollination transfers pollen to the stigma of the same flower.
• Cross-pollination transfers pollen to the stigma of a different flower.
• Fertilization fuses male gamete (pollen) with female gamete (ovule) to form a zygote.
• The zygote develops into an embryo, and the ovule into a seed.
• Seed dispersal scatters seeds away from the parent via wind, water, or animals.

Forest: Our Lifeline

• Forests are key natural resources with numerous benefits.
• Forests provide timber, medicines, and other useful products.
• Forests help maintain oxygen and carbon dioxide balance.
• Forests prevent soil erosion and aid water conservation.
• Deforestation (forest clearing) causes soil erosion, biodiversity loss, and climate change.
• Forest conservation is vital for ecological balance and sustainable development.