Final answer:
The common rule states that animals have four basic types of tissue, but it doesn't always apply to human tissues due to variations and complexities in classification and organization.
Step-by-step explanation:
The common rule refers to the idea that all animals, including humans, have four basic types of tissue: epithelial, connective, muscle, and nervous tissue. These tissues are responsible for various functions in the body and make up the organs and structures within it.
However, the common rule does not necessarily apply to human tissues because there is variation and complexity in the classification and organization of tissues. For example, blood, cartilage, and bone are considered connective tissues, but they differ significantly from other connective tissues. Additionally, there are embryonic connective tissues that have their own classification.
In summary, while the common rule provides a broad understanding of tissue types, it is important to recognize that human tissues can also have unique characteristics and classifications that deviate from this rule.