Aadya Isai

1. Definition:- A rapid growth of microscopic algae in water, often resulting in à coloured scum on the surface.

   An algal bloom is a rapid, excessive growth of algae in fresh water or marine environments, often turning the water discoloured (green, red, brown) due to high nutrient levels, especially nitrogen and phosphorus from fertiliser runoff or wastewater.

   
   

   These blooms can be harmless but are often harmful, causing oxygen depletion (hypoxia) that kills fish and other aquatic life.

1) Introduction:

A) Definition:- Pollution is the introduction of harmful substances or energy (like - heat, sound, light) into the natural environment, causing adverse effects on living organisms and ecosystems, making the surrounding impure and unsafe.

B) Causes:- Pollution stems rein hunan activities like burning fossil fuels for energy and transport; industrial emission, vehicle exhaust, agricultural chemicals (pesticides/fertilisers), and improper waste disposal (sewage, plastic, garbage burning).

2) Causes of water pollution:

A. Factories:- Factories cause water pollution by discharging untreated waste water filled with toxic chemicals, heavy metals (like-led, mercury) dyes, oils, and pathogens into rivers, lakes, and groundwater.

B. House hold works:- House holds pollutes water through untreated sewage release, poor drainage systems, and ground water sewage.

Animal population size is shaped by growth factors (like - birth and immigration) and population decline (like - deaths and emigration), all controlled by limiting factors like food supply, water, shelter, predation, diseases, space, as well as environmental conditions (climate, light) and biological interactions (competition, symbiosis) ultimately determining the habitat’s carrying capacity.

How food supply impacts growth: A) Food supply:

Food supply is a primary driver of animal population size; abundant food allows for more births and better survival, leading to population growth, while scarcity cause declines through starvation, reduced reproduction, and increased stress/predation.

B) Predators:

• Predation significantly effects animal population by creating dynamic cycles; more prey leads to move predators, which then reduces the prey to rebound, and restarting the cycle.

1. Definition:

   • Population is the total number of individuals of the same species living in a specific area at a particular time.

   
   

2. Why is population important?

   Population is important because it determines how living organisms survive, interact, and use resources in an area.

   
   

   • Population size helps us understand how many individuals of a species are living in a place and whether their numbers are increasing or decreasing.

   
   

   • It affects the availability of food, water, space, and shelter, since resources are limited.