📘 Chapter 6 – Tissues
🧠 Easy & Notes
🔹 1. What is Tissue?
- Group of similar cells that perform a specific function.
- Cells in tissues work together.
- Tissue → Organ → Organ System → Organism
🔹 2. Types of Tissues
A. Plant Tissues
🔸 I. Meristematic Tissue (Dividing Tissue)
| Type | Location | Function |
|---|---|---|
| Apical | Tip of root and shoot | Helps in growth |
| Intercalary | Base of leaves | Helps in increasing length |
| Lateral | Sides of stem/root | Increases thickness |
Features: Small cells, dense cytoplasm, no vacuoles, divide continuously.
🔸 II. Permanent Tissue (Non-Dividing)
a) Simple Permanent Tissue
| Type | Function | Examples |
|---|---|---|
| Parenchyma | Storage, support | Stem, roots |
| Collenchyma | Flexibility, support | Leaf stalks |
| Sclerenchyma | Strength, thick walls | Husk of coconut |
b) Complex Permanent Tissue (Transport)
| Tissue | Function |
|---|---|
| Xylem | Transports water |
| Phloem | Transports food |
B. Animal Tissues
🔸 I. Epithelial Tissue (Covering Tissue)
| Type | Function |
|---|---|
| Squamous | Protection |
| Cuboidal | Absorption/secretion |
| Columnar | Absorption |
| Ciliated | Move mucus, egg, etc |
| Glandular | Secretion |
🔸 II. Connective Tissue
| Type | Function |
|---|---|
| Blood | Transport oxygen, nutrients |
| Bone | Support and structure |
| Ligament | Connect bone to bone |
| Tendon | Connect muscle to bone |
| Cartilage | Smooth surface in joints |
| Areolar tissue | Fills space, binds skin/muscle |
| Adipose tissue | Fat storage |
🔸 III. Muscular Tissue
| Type | Features |
|---|---|
| Striated | Voluntary, striped, many nuclei |
| Smooth | Involuntary, no stripes |
| Cardiac | Heart muscles, involuntary, branched |
🔸 IV. Nervous Tissue
- Neurons: Carry messages in form of electrical impulses
- Brain, spinal cord, nerves.
✅ MCQs
- The basic unit of a tissue is:
a) Organ
b) Cell
c) Organ system
d) Blood - Which of the following is a simple permanent tissue?
a) Xylem
b) Parenchyma
c) Phloem
d) Blood - Which connective tissue connects bone to bone?
a) Tendon
b) Ligament
c) Cartilage
d) Areolar - Cardiac muscles are found in:
a) Lungs
b) Liver
c) Heart
d) Kidneys - The tissue responsible for transport of water is:
a) Phloem
b) Parenchyma
c) Xylem
d) Collenchyma - Squamous epithelium is:
a) Cube shaped
b) Flat shaped
c) Column-like
d) Branched - Which tissue helps in bending of plant stems?
a) Parenchyma
b) Collenchyma
c) Xylem
d) Phloem - Which animal tissue has fluid matrix?
a) Cartilage
b) Blood
c) Bone
d) Ligament - Which is an involuntary muscle?
a) Skeletal
b) Cardiac
c) Striated
d) Voluntary - Intercalary meristem is present at:
a) Tip of shoot
b) Base of leaf
c) Side of stem
d) Tip of root - Phloem transports:
a) Water
b) Salts
c) Food
d) Oxygen - Which connective tissue joins muscle to bone?
a) Ligament
b) Cartilage
c) Tendon
d) Areolar - Nervous tissue is made of:
a) Muscles
b) Neurons
c) Ligaments
d) Bone cells - Ciliated epithelium is found in:
a) Skin
b) Nose and throat
c) Heart
d) Bone - Sclerenchyma cells are:
a) Thin-walled
b) Dead cells
c) Living cells
d) Green in colour
✅ Assertion and Reason
A: Xylem helps in water transport.
R: Xylem contains vessels and tracheids.
a) Both A and R are true, R explains A
b) Both A and R are true, R doesn’t explain A
c) A true, R false
d) A false, R true
A: Cardiac muscles are involuntary.
R: They are found in the heart.
a) Both A and R are true, R explains A
b) Both A and R are true, R doesn’t explain A
c) A true, R false
d) A false, R true
A: Ligaments connect muscles to bones.
R: Ligaments have flexibility.
a) Both A and R are true, R explains A
b) Both A and R are true, R doesn’t explain A
c) A true, R false
d) A false, R true
A: Parenchyma provides flexibility.
R: It has thick corners.
a) Both A and R are true, R explains A
b) Both A and R are true, R doesn’t explain A
c) A true, R false
d) A false, R true
A: Blood is a connective tissue.
R: It transports food and gases.
a) Both A and R are true, R explains A
b) Both A and R are true, R doesn’t explain A
c) A true, R false
d) A false, R true
✅ Case-Based Study
📘 Passage:
A student observed cross sections of plant stems and roots under a microscope. He noticed thick-walled cells in outer layers (sclerenchyma), water-carrying tissues in the center (xylem), and flexible tissues near corners (collenchyma). He also observed that leaves had cells for photosynthesis and storage.
- Which tissue gives mechanical strength?
a) Parenchyma
b) Collenchyma
c) Sclerenchyma
d) Xylem - Xylem is responsible for transporting:
a) Food
b) Hormones
c) Water
d) Air - Which plant tissue has living cells with thick corners?
a) Sclerenchyma
b) Collenchyma
c) Xylem
d) Phloem - Which part stores food in plants?
a) Parenchyma
b) Xylem
c) Collenchyma
d) Epidermis - Leaf tissues mainly do:
a) Water transport
b) Photosynthesis
c) Movement
d) Muscle support
✅ Reason-Based Questions
- Why is meristematic tissue important for plants?
Because it helps in the growth of plants by continuously dividing. - Why is xylem considered a complex tissue?
Because it is made of different types of cells like vessels, tracheids, fibers, etc. - Why are parenchyma cells called living cells?
Because they have a nucleus and perform functions like storage and photosynthesis. - Why is blood called a connective tissue?
Because it connects different parts of the body by transporting oxygen and nutrients. - Why do tendons connect muscles to bones?
Because tendons are strong and help transmit force during movement. - Why do cardiac muscles never get tired?
Because they work continuously and have many mitochondria for energy. - Why are sclerenchyma cells dead?
Because they lose their cytoplasm and become hard to give strength. - Why are neurons important in our body?
Because they carry messages and signals from one part to another. - Why are epithelial tissues tightly packed?
Because they cover body surfaces and need to protect against germs and injury. - Why does adipose tissue store fat?
Because fat acts as energy storage and insulation. - Why are collenchyma cells flexible?
Because they have unevenly thick walls which allow bending of plant parts. - Why is areolar tissue present under skin?
Because it binds skin to muscles and fills spaces inside organs. - Why is phloem necessary in plants?
Because it transports food made in leaves to other parts. - Why do animals need muscular tissues?
Because muscles help in movement of body parts. - Why are bones hard and strong?
Because they are made of calcium and give support and shape to the body.
✅ Answer Key
MCQs:
1–b, 2–b, 3–b, 4–c, 5–c, 6–b, 7–b, 8–b, 9–b, 10–b, 11–c, 12–c, 13–b, 14–b, 15–b
Assertion & Reason:
16–a, 17–a, 18–d, 19–d, 20–a
Case-Based:
21–c, 22–c, 23–b, 24–a, 25–b