Exhaustive Study Notes on Life Processes

• Living beings exhibit observable actions (e.g., breathing). Molecular movements are crucial for life; viruses only show movement when they infect a host. Organisms must maintain order through continuous molecular movement.

Life Processes

• Defined as all functions that ensure the maintenance and survival of an organism.

• Require constant energy sourced from nutrition:

  • Autotrophs: Organisms that derive nutrients from inorganic materials (e.g., plants).

  • Heterotrophs: Organisms that consume complex substances (e.g., animals, humans).

Photosynthesis

• Autotrophs utilize sunlight to convert CO₂ and water into carbohydrates.

• These carbohydrates are stored as starch in plants and glycogen in humans.

Digestion in Humans

• The alimentary canal acts as a long tube extending from the mouth to the anus, composed of specialized regions for digestion.

• Digestion initiates in the mouth with enzymatic action and concludes in the small intestine.

Circulation

• The heart pumps blood through a double circulation system, keeping oxygenated and deoxygenated blood separate.

Excretion

• The human excretory system consists of the kidneys, ureters, bladder, and urethra, responsible for removing metabolic wastes.

• In plants, excretion involves the release of oxygen and water through a process known as transpiration.

Gas Exchange

• In humans, gas exchange occurs primarily in the alveoli of the lungs.

• Hemoglobin in red blood cells efficiently transports oxygen throughout the body.