Class 9 Tissue: Plant, Animal & Nervous Tissue

Introduction

• The instructor is addressing issues in the provision of Class 9th Tissue lessons.
• Students face exam stress and struggle with memory retention.
• Conceptual teaching is used to enhance understanding, moving away from rote memorization.
• Additional science chapters are available in the playlist.

Energetic Start

• Learning should be approached with high energy.
• Students are encouraged to show enthusiasm, with a "Josh meter" goal of over 1000.

Teaching Approach

• Storytelling helps students understand tissues.

Topics Covered

• Tissues
• Plant tissue
• Permanent tissue
• Animal tissue
• Nervous tissue

What are Tissues?

• Cells are the basic units of life.
• Tissues are groups of cells with similar shapes and functions working together.
• Cells form tissues, tissues form organs, organs form organ systems, and organ systems form organisms.

Utility of Tissues in Multicellular Organisms

• Tissues enable bodily functions in multicellular organisms
• They form organs and organ systems for excretion, digestion, respiration, etc.
• Tissue organization allows specific activities.

Plant and Animal Tissues Overview

• Plant Tissues:
  • Meristematic Tissue: For plant growth, contains dividing cells.
  • Permanent Tissue: Not focused on growth, cells don't divide.

Key Differences Between Meristematic and Permanent Tissues

• Goal:
  • Meristematic: Growth-focused
  • Permanent: Not growth-focused
• Cells:
  • Meristematic: Capable of dividing
  • Permanent: Cannot divide
• Cell Shape/Size:
  • Meristematic: Small cells, same shape
  • Permanent: Large cells, different shapes
• Vacuoles:
  • Meristematic: Usually absent to allow cell division
  • Permanent: Present
• Intracellular Spaces:
  • Meristematic: Absent
  • Permanent: Present
• Cell Wall:
  • Meristematic: Thin, to aid division
  • Permanent: Thick or thin

Types of Meristematic Tissue

• Apical Meristem:
  • Located at stem, root, and leaf tips.
  • Facilitates shoot and root lengthening (primary growth).
• Lateral Meristem:
  • Causes stem and root thickening (secondary growth).
  • Thickness is called 'girth'.
• Intercalary Meristem:
  • Located at leaf bases and between knots.
  • Aids growth of internal nodes and leaves.

Apical Meristem Subtypes

• Shoot Apical Meristem: Top of the shoot/stem
• Root Apical Meristem: Located in the root

Wound Healing in Plants

• Meristematic tissues repair wounds via cell division.
• Cell division restores injured areas.

Permanent Tissue Fundamentals

• Cells don't divide, growth is not the focus.
• Intercellular spaces exist.

Differentiation Process

• Meristematic tissues become permanent tissues through differentiation.

Permanent Tissue Types

• Simple Permanent Tissue: Same cell type
• Complex Permanent Tissue: Different cell types

Simple Permanent Tissue Types

• Parenchyma:
  • Supports plants and stores food in stems and roots.
  • Contains simple, unspecialized cells.
  • Cells are thin-walled and alive.
  • Loosely packed.
• Collenchyma:
  • Found in leaf stalks.
  • Provides flexibility.
  • Living cells.
  • Thick corners with little space.
• Sclerenchyma:
  • Provides toughness and rigidity.
  • Contains dead cells.
  • Thick cell walls.
  • May contain lignin for toughness.

Parenchyma Subtypes

• Chlorenchyma:
  • Contains chlorophyll for photosynthesis.
• Aerenchyma:
  • Fills cell spaces with air for lightness.
  • Allows aquatic plants like lotus to float.

Complex Permanent Tissue

• Consists of Xylem and Phloem.
• Xylem provides water.
• Phloem provides food.

Xylem Description

• Transports water throughout the plant.
• Also known as wood.
• Made from thick-walled cells.
• Consists of Tracheids, Vessels, Xylem Parenchyma, and Xylem Fibers.
• Three out of four are dead, except xylem parenchyma
• Tracheids and Vessels transport water.
• Xylem Parenchyma stores food.
• Xylem fibers provide support.

Phloem Description

• Transports food throughout the plant.
• Consists of Sieve Tube, Companion Cell, Phloem Fibers, and Phloem Parenchyma.
• Sieve tubes use companion cells.

Xylem vs Phloem in Plant Tissue

• Transports:
  • Xylem: Water in one direction
  • Phloem: Food in multiple directions
• Cells:
  • Xylem: Mostly dead cells
  • Phloem: Mostly living cells
• Provides:
  • Xylem: Mechanical strength
  • Phloem: Tissue support only

Protective Tissue Functions

• Epidermis and Cork Tissue provide protection.

Epidermis Function

• Protects from injury and other conditions
• Is the outermost layer
• Controls surface input/output
• Prevents water loss
• Facilitates gas exchange

Cork Description

• Bark on tree stems providing security.
• Prevents bacteria and provides heat.

Animal Tissue Discussion and Type

• Human tissue that protects
• Epithelial, Muscular, Connective, and Nervous tissues comprise animal tissues

Epithelial Tissue

• Outer layer protecting all organs
• Thin, singular cell layers
• Lacks blood vessels
• Non-nervous

Epithelial Tissue Types

• Types: Squamous, Stratified Squamous, Cuboidal, Columnar, Ciliated
• Squamous Epithelium: Single layer around blood vessels for protection.
• Stratified Squamous Epithelium: Two-layered, acts as skin.
• Cuboidal Epithelium: Cube-shaped cells.
• Columnar Epithelium: Column-shaped cells.
• Ciliated Epithelium: Hair-like tissue.

Muscular Tissue Description

• Facilitates muscle movement
• Long, fiber-like cells move muscles.

Types of Muscular Tissues

• Striated: Voluntary muscle with controllable movement.
• Smooth Muscle: Involuntary muscle with spindle shape.
  • Example: Esophagus smooth muscle aids digestion.
• Cardiac: Involuntary heart muscle for blood pumping.

Muscular Tissue Chart

• Movement:
  • Striated: Controllable
  • Smooth & Cardiac: Incontrollable
• Location:
  • Striated: In bones
  • Smooth: In internal organs
  • Cardiac: In the heart
• MultiNucleate:
  • Striated: No
  • Smooth: Yes
  • Cardiac: Yes
• Cytoplasm: Sarcoplasm
• Tired:
  • Striated: Yes
  • Smooth & Cardiac: No
• Control: Striated controls movement. Smooth and Cardiac control flow.

Animal Tissue Connective

• Connects body parts, protects against infection, and stores fat
• Fluid tissue: Blood
• Blood transports gases, digested food, and hormones.

Blood Description

• Fluid tissue
• Transports gases, digested food, and hormones

Parts of Blood

• Plasma: 90% water
• Red Blood Cell (RBC): Erythrocytes, give blood red color.
• White Blood Cell (WBC): Protection/Soldier cells, fight disease.
• Blood Platelets: Thrombocytes, clot blood.

Difference between Ligament VS Tendons

• Connects:
  • Ligament: Bone to bone (B2B)
  • Tendon: Bone to muscle (B2M)
• Elasticity:
  • Ligaments: Elastic connection
  • Tendons: Movement source, less elastic
• Color:
  • Ligaments: Yellow (elastin fiber)
  • Tendons: White (less blood)

Differences between Cartilage vs Bone

• Cartilage: Soft, elastic, flexible
• Bone: Strong, hard
• Cartilage: Grows in any direction
• Bones: Don't grow in may directions

Differences between Areolar VS Adipose tissue

• Both are connective tissues
• Areolar fills organ space, especially between skin and muscle.
• Adipose stores fat for nutrients.

Human Nervous System

• Sends signals via stimulus.
• Example: Touching hot object sends pain through brain and spinal cord.

Nerves Description

• Spinal cord dictates body reactions via signals.

Important

• Neurons are the longest and functional portion.
• Neuron cell body: Cyton
• Neuron Structure: Dendrites receive, process, send signals to Axon.

Neuron's Purpose

• Dendrites: Collect signals.
• Axon: Signal travels for processing, carries nerve signals.
• Nerves can chain for more brain connections
• Neuron's purpose:
  • Dendrites
  • Axon
  • Nerve Ending

Difference between Animal vs Plant Tissue

• Movement:
  • Plants: No muscular tissue
  • Animals: Muscular tissue
• Cells:
  • Plants: Mostly dead cells
  • Animals: Mostly living cells
• Stationary vs Movement.

Stationary versus Movement

• Plant Growth is slower vs animal, with the location of plant growth is in plants versus random in animals
• animal can have different layers of connection in tissue types versus plant which is just basic vs complex
• Animal tissues are more complex than plant tissues.

End note for learning

• Maintain a positive attitude while learning.

Learn about tissues in Class 9, including plant, permanent, animal, and nervous tissues. Understand the function of tissues, which are groups of cells with similar shapes working together. The instructor uses storytelling to explain the concepts.