Excretion

Excretion is the process by which metabolic wastes and other non-useful materials are eliminated from an organism. This process is essential for maintaining homeostasis and ensuring the body's internal environment remains stable.

Organs Involved in Excretion

Kidneys: The primary organs of excretion in humans. They filter the blood to remove waste products and excess substances, forming urine.
Lungs: Excrete carbon dioxide and water vapor during respiration.
Skin: Eliminates waste products through sweat, including water, salts, and small amounts of urea.
Liver: Processes and eliminates metabolic waste products, as well as detoxifying various substances in the body.

Types of Waste Products

Waste products that are excreted from the body include:

Urea: Formed in the liver as a byproduct of protein metabolism and excreted by the kidneys in urine.
Carbon Dioxide: Produced during cellular respiration and excreted by the lungs during exhalation.
Excess Salts: Removed by the kidneys in urine or through sweat from the skin.
Water: Excreted in urine, sweat, and through respiration to maintain water balance in the body.

Regulation of Excretion

Excretion is regulated by various hormones and feedback mechanisms in the body, including:

Antidiuretic Hormone (ADH): Regulates water reabsorption in the kidneys to control urine concentration.
Aldosterone: Controls the reabsorption of sodium and potassium ions in the kidneys to regulate blood pressure and electrolyte balance.
Renin-Angiotensin-Aldosterone System: Regulates blood pressure and fluid balance through the release of renin, angiotensin, and aldosterone.

Excretion in Plants

Plants excrete waste products through various mechanisms, including the release of oxygen during photosynthesis, the elimination of excess water through transpiration, and the storage of waste products in vacuoles within plant cells.

Study Tips

When studying excretion, it's important to understand the functions of the different excretory organs, the types of waste products eliminated, and the regulatory mechanisms involved in maintaining homeostasis. Practice drawing and labeling the excretory system and its components to reinforce your understanding.

◂Biology Worksheets and Study Guides High School. Food Chains and Food Webs

Worksheet/Answer key

Food Chains and Food Webs

Worksheet/Answer key

Food Chains and Food Webs

Worksheet/Answer key

Food Chains and Food Webs

Vocabulary/Answer key

Food Chains and Food Webs

Vocabulary/Answer key

Food Chains and Food Webs

The resources above cover the following skills:

Concepts Of Biology: The student will demonstrate the ability to use scientific skills and processes (Core Learning Goal 1) and major biological concepts to explain the uniqueness and interdependence of living organisms, their interactions with the environment, and the continuation of life on earth.

The student will be able to explain the correlation between the structure and function of biologically important molecules and their relationship to cell processes.

The student will be able to compare the transfer and use of matter and energy in photosynthetic and non-photosynthetic organisms.

The student will investigate the interdependence of diverse living organisms and their interactions with the components of the biosphere.

The student will analyze the interrelationships and interdependencies among different organisms and explain how these relationships contribute to the stability of the ecosystem.

The student will illustrate how all organisms are part of and depend on two major global food webs that are positively or negatively influenced by human activity and technology.

Environmental Science: The student will demonstrate the ability to use the scientific skills and processes (Core Learning Goal 1) and major environmental science concepts to understand interrelationships of the natural world and to analyze environmental issues and their solutions.

The student will investigate the interdependence of organisms within their biotic environment.

The student will explain how organisms are linked by the transfer and transformation of matter and energy at the ecosystem level (At least - Photosynthesis/respiration; Producers, consumers, decomposers; Trophic levels; Pyramid of energy/pyramid of biomass).