Tissues
Biology · ऊतक
📋Quick Overview
A tissue is a group of similar cells performing a specific function. Plant tissues are Meristematic (dividing, at growing tips) and Permanent (simple — parenchyma, collenchyma, sclerenchyma; complex — xylem, phloem). Animal tissues are Epithelial (covering), Connective (binding/support), Muscular (movement), and Nervous (signal transmission).
📖Plant Tissues
| Tissue | Type | Location | Function |
|---|---|---|---|
| Meristematic | Dividing cells | Root tips, Shoot tips, Cambium | Growth — cells divide continuously |
| Parenchyma | Simple permanent | Throughout the plant | Storage, photosynthesis (chlorenchyma), buoyancy (aerenchyma) |
| Collenchyma | Simple permanent | Below epidermis (leaf stalks) | Flexibility + support (thickened corners) |
| Sclerenchyma | Simple permanent | Seed coats, nut shells | Rigidity + strength (dead cells, lignin) |
| Xylem | Complex permanent | Vascular plants | Transports WATER & minerals UP (root to leaf). Mostly dead cells. |
| Phloem | Complex permanent | Vascular plants | Transports FOOD (sucrose) up & down. Living cells. |
📖Animal Tissues
| Tissue | Function | Types | Location |
|---|---|---|---|
| Epithelial | Covering & protection | Squamous, Cuboidal, Columnar, Glandular | Skin, mouth lining, intestine, blood vessels |
| Connective | Binding, support, transport | Blood, Bone, Cartilage, Tendon, Ligament, Adipose | Bones, blood, tendons |
| Muscular | Movement & contraction | Striated (skeletal), Smooth (involuntary), Cardiac (heart) | Limbs, organs, heart |
| Nervous | Signal transmission | Neurons (dendrite→cell body→axon) | Brain, spinal cord, nerves |
⭐
Blood is a connective tissue (liquid). Bone is hardest connective tissue. Tendon connects muscle to bone. Ligament connects bone to bone. Cardiac muscle is involuntary + striated.