Excretion Study Guide
What is Excretion?
Excretion is the process of removing waste products and harmful substances from the body.
Organs Involved in Excretion
- Kidneys: They filter the blood to remove waste products and excess substances, producing urine as a result.
- Lungs: They remove carbon dioxide, a waste product of cellular respiration, during exhalation.
- Skin: Sweat glands in the skin excrete water, salts, and small amounts of urea in the form of sweat.
- Intestines: They excrete solid waste in the form of feces, which contains undigested food and other waste products.
Importance of Excretion
Excretion is essential for maintaining the body's internal balance by eliminating waste products and regulating the levels of substances such as water, salts, and gases.
Common Waste Products
Waste products excreted from the body include urea, carbon dioxide, water, salts, and other metabolic by-products.
Disorders Related to Excretion
Disorders such as kidney stones, urinary tract infections, and kidney failure can affect the excretory system and lead to imbalances in the body.
.◂Science Worksheets and Study Guides Third Grade. Relationships among living things
Study Guide
Relationships among living things 
Activity Lesson
Relationships Among Living Things Worksheet/Answer key
Relationships among living things Worksheet/Answer key
Relationships among living things Worksheet/Answer key
Relationships among living things Worksheet/Answer key
Relationships among living things Vocabulary/Answer key
Relationships among living things Vocabulary/Answer key
Relationships among living things
Activity LessonWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyVocabulary/Answer keyVocabulary/Answer keyThe resources above cover the following skills:
LIFE SCIENCE
From Molecules to Organisms: Structures and Processes
Create representations to explain the unique and diverse life cycles of organisms other than humans (e.g., flowering plants, frogs, butterflies), including commonalities such as birth, growth, reproduction, and death.
Unity and Diversity
Construct an argument from evidence to explain the likelihood of an organism’s ability to survive when compared to the resources in a certain habitat (e.g., freshwater organisms survive well, less well, or not at all in saltwater; desert organisms survive well, less well, or not at all in woodlands).
Create models that illustrate how organisms and their habitats make up a system in which the parts depend on each other.