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Birth Control and Contraception
Birth Control and Contraception

Different pregnancy and birth control and contraception strategies are described. Read this tutorial to learn each of th..

Water Cycle
The Water Cycle

The water cycle (also referred to as the hydrological cycle) is a system of continuous transfer of water from the air, s..

Early Earth
The Origins of Life

This tutorial digs into the past to investigate the origins of life. The section is split into geological periods in the..

Physical growth
Physical Development in Humans

This tutorial elaborates on the physical development of humans, particularly from puberty to adulthood. Read this tutori..

Types and Causes of Brain Damage
Types and Causes of Brain Damage

This tutorial describes the different types and causes of brain damage. Find out how genetics, physical injury, lack of ..

sponge
Primitive Animals

Life, as we know it today, is presumed to have started in the sea and many of them were likely eukaryotic animal-like or..