This chapter explains that in multicellular organisms, similar cells group together to perform specific functions, forming tissues. It highlights how division of labour makes life processes more efficient in plants and animals. The chapter describes different types of plant tissues, including meristematic tissues responsible for growth and permanent tissues that provide support, storage, and transport. It also explains animal tissues such as epithelial, connective, muscular, and nervous tissues, showing how structure is closely related to function. Through examples from daily life, the chapter helps students understand how tissues form the building blocks of organs and organ systems.
Key Points
A tissue is a group of similar cells performing a specific function.
Multicellular organisms show division of labour at the tissue level.
Plants and animals have different types of tissues due to different lifestyles.
Plant tissues are classified as meristematic and permanent tissues.
Meristematic tissues are actively dividing and help in plant growth.
Apical meristem increases length, lateral meristem increases girth, and intercalary meristem helps regrowth.
Permanent tissues are formed after differentiation of meristematic cells.
Simple permanent tissues include parenchyma, collenchyma, and sclerenchyma.
Parenchyma stores food and may help in photosynthesis and buoyancy.
Collenchyma provides flexibility and mechanical support.
Sclerenchyma provides strength and rigidity to plant parts.
Complex permanent tissues include xylem and phloem.
Xylem transports water and minerals, while phloem transports food.
Animal tissues are classified as epithelial, connective, muscular, and nervous tissues.
Epithelial tissue provides protection, absorption, and secretion.
Connective tissue supports, binds, and transports materials in the body.
Muscular tissue helps in movement through contraction and relaxation.
Striated muscles are voluntary, smooth muscles are involuntary, and cardiac muscles work continuously.
Nervous tissue receives and transmits impulses for coordination.
👉 👉Living organisms are highly organised systems where every tissue has a specific role. Understanding tissues helps us appreciate how structure and function work together to maintain life, growth, and coordination in plants and animals.