How groups of similar cells share the work in plants and animals
A tissue is a group of similar cells that work together to perform a specific function. Plant tissues are meristematic or permanent. Meristematic tissues, found at root and shoot tips (apical), in stems (lateral) and at the base of leaves (intercalary), keep dividing and help plants grow. Permanent tissues include simple tissues like parenchyma for storage, collenchyma for flexibility and sclerenchyma for strength, as in husk of coconut. Complex tissues are xylem, which carries water, and phloem, which carries food.
Animal tissues are of four types. Epithelial tissue covers body surfaces and lines organs; it can be squamous, cuboidal or columnar. Connective tissue includes blood, bone, cartilage, tendons that join muscle to bone and ligaments that join bone to bone. Muscular tissue has three types: striated muscles that move limbs, smooth muscles in the stomach and blood vessels that work involuntarily, and cardiac muscles of the heart that never tire. Nervous tissue is made of neurons that carry messages quickly.
Why it matters
Tissues explain how plants grow taller and thicker, why coconut husk and jute fibres are strong, and how wounds heal. Doctors study tissue samples, called biopsies, to diagnose diseases such as cancer. Knowing about ligaments and tendons helps athletes understand sports injuries. This topic connects cells to organs and organ systems.
Key terms
- Tissue
- A group of similar cells working together to perform a particular function.
- Meristematic tissue
- Plant tissue whose cells keep dividing, found at growing regions.
- Xylem
- Plant tissue that carries water and minerals from roots to leaves.
- Connective tissue
- Animal tissue that binds, supports and connects other tissues, such as bone and blood.