Protection, Reproduction and Cooperation
The human body protects itself with non-specific defense systems that react naturally and automatically to invading organisms. Your skin, with its layers of protective tissue, is a very strong, watertight barrier to environmental pathogens. What is an Antigen? A antigen is a molecule that immune system can recognize as either part of the body or as foreign to the body.
◂Science Worksheets and Study Guides Sixth Grade. Protection, Reproduction and Cooperation
Worksheet/Answer key
Protection, Reproduction and Cooperation 
Worksheet/Answer key
Protection, Reproduction and Cooperation Worksheet/Answer key
Protection, Reproduction and Cooperation Vocabulary/Answer key
Protection, Reproduction and Cooperation Vocabulary/Answer key
Protection, Reproduction and Cooperation Vocabulary/Answer key
Protection, Reproduction and Cooperation
Worksheet/Answer keyWorksheet/Answer keyVocabulary/Answer keyVocabulary/Answer keyVocabulary/Answer keyThe resources above cover the following skills:
Reading Standards for Literacy in Science and Technical Subjects
Craft and Structure
Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 6-8 texts and topics.