Animal cells, plant cells and organisation of life

The Cell

• Basic Building Blocks: Cells are essential components of all living organisms.

Microscopy

• Equipment Components:

  • Body Tube

  • Revolving Nosepiece

  • Objectives

  • Stage Clips

  • Diaphragm

  • Light Source

  • Ocular Lens (Eyepiece)

  • Arm

  • Stage

  • Coarse Adjustment Knob

  • Fine Adjustment Knob

  • Base

Preparing Wet Mounts

• Steps to create a wet mount:

  1. Add a drop of water to a slide.

  2. Place the specimen in the water.

  3. Use a coverslip:

     • Place the edge on the slide so it touches the water.

     • Slowly lower to avoid trapping air bubbles.

Characteristics of Cells

• Cells as Units of Life:

  • All living organisms are composed of cells.

  • Cells are microscopic and the fundamental units of life.

  • Unicellular organisms (e.g., Amoeba) vs. multicellular organisms.

  • Fertilization creates a zygote; cells begin to divide and differentiate.

Animal Cell Structure

• Key Components:

  • Cell membrane

  • Cytoplasm

  • Nucleus

  • Mitochondrion (not always visible)

Amoeba Structure

• Structure includes:

  • Cell membrane

  • Nucleus

  • Cytoplasm

  • Pseudopods (used for movement and feeding)

  • Contractile vacuole (excretes water and waste)

  • Food vacuole (digests food)

Human Cheek Epithelial Cells

• Example of animal cells that are easily observable.

Bacteria

• Characteristics:

  • No true nucleus.

  • Structure includes cytoplasm, cell wall, plasmid DNA.

  • Flagellum (not always present).

Varieties of Animal Cells

• Different types of animal cells:

  • White blood cells

  • Red blood cells

  • Sperm cells

  • Cheek cells

  • Muscle cells

  • Nerve cells

Specialized Cells

• Types of specialized cells:

  • Surface skin cells

  • Blood cells

  • Bone cells

  • Cardiac muscle cells

  • Neurons

  • Skeletal muscle cells

  • Smooth muscle cells

Plant Cell Structure

• Key Components:

  • Cell wall (provides structure)

  • Cell membrane (encloses the cell)

  • Cytoplasm

  • Vacuole (contains cell sap)

  • Nucleus

  • Chloroplasts (for photosynthesis)

Plant Cell Differentiation

• Types of plant cells:

  • Meristem cells

  • Parenchyma cells

  • Sclerenchyma cells (fiber)

  • Companion cells

  • Collenchyma cells

  • Tracheid and sieve tube cells

Differences Between Plant and Animal Cells

• Plant Cell:

  • Has a cellulose cell wall.

  • Fixed shape.

  • Contains chloroplasts.

  • Large central vacuole.

• Animal Cell:

  • No cell wall.

  • No fixed shape.

  • No chloroplasts.

  • Small or no vacuole.

Onion Epidermal Cells

• Another example of plant cells under a microscope.

Organization of Life

• Levels of biological organization:

  • Cellular Level: Basic unit of life.

  • Tissue Level: Group of similar cells performing the same function.

  • Organ Level: Multiple tissue types functioning together.

  • System Level: Group of organs working together.

  • Organismal Level: All systems combine to form an organism.

Specialized Cell Functions

• Each type of specialized cell has distinct functions:

  • Cells work together to form tissues; four types:

    • Epithelial

    • Connective

    • Muscle

    • Nervous

  • Organs are formed by various tissues that work together.

  • Organ Systems consist of multiple organs functioning in unison.

Stem Cell Applications

• Potential Applications:

  • Muscle cells for cardiac recovery.

  • Blood cells for leukemia treatments.

  • Nerve cells for conditions like Parkinson's.

  • Islet cells for diabetes management.

  • Retinal cells to address blindness.