Case Study Questions for Class 9 Science Chapter 3 Tissues in Action (Exploration Book) 2026-27

Plants grow in different ways – increase in length, increase in girth, and regrowth after cutting. This growth requires actively dividing cells that together form a tissue called a meristematic tissue. The apical meristem, located at the root and shoot tips, increases its length. The lateral meristem located along the circumference of stems increases girth. The intercalary meristem located at the base of certain plants, such as grasses, helps them regenerate after cutting.

The cells of the meristematic tissues are small, have thin cell walls, a large and prominent nucleus, and dense cytoplasm with many organelles. Due to continuous cell division, they add new cells to the plant body. The cells that lose the ability to divide undergo changes in structure and function, and become permanent tissues through a process called differentiation.

Like plants, animal cells also group together to form tissues specialised in performing different functions. Movements under our conscious control, such as running or lifting objects, are carried out by skeletal muscles. These muscles are attached to the bones of the skeleton by strong, flexible bands of connective tissue called tendons.

When a muscle contracts, the tendon transmits this force to the bone, resulting in movement at a joint. For instance, the hinge joint present in the knee and elbow allows movement primarily in one plane. All these actions, whether voluntary or involuntary, are ultimately controlled and coordinated by nervous tissue. Nervous tissue consists of neurons that are specialised to receive, process, and transmit messages throughout the entire body.