Microscopes and Cell Structures

Microscopes

Instruments used to magnify small objects, allowing scientists to see tiny building blocks that make up living things.

Microscopic

Describes objects that can only be seen using a microscope.

Light Microscope

Type of microscope that uses light passing through a specimen and a series of lenses to magnify the object.

Stereo Microscope

Microscope that provides a three-dimensional view by using two monocular microscopes focusing on the same point from different angles.

Magnification

The factor by which a microscope enlarges an image compared to the real object, indicated by a number followed by '×'.

Field of View

The area visible when looking through a microscope; decreases as magnification increases.

Micrometre (µm)

One-thousandth of a millimetre or one-millionth of a metre, commonly used to measure microscopic objects.

Electron Microscopes

Powerful microscopes that use beams of electrons instead of light, capable of magnifying up to a million times.

Cell Theory

Scientific theory stating that cells are the basic building blocks of all living organisms, proposed by Schleiden and Schwann in the 19th century.

Robert Brown

Scottish botanist who discovered the cell nucleus and identified structures within plant cells in the 19th century.

Matthias Schleiden

German scientist who proposed that cells are the basic unit of all plants and new plants start as a single cell.

Theodor Schwann

Scientist who proposed that animals are also made of cells, establishing cells as the basic unit of life for both plants and animals.

Karl Nägeli

Swiss scientist who observed cells dividing to form new cells, contributing to the understanding of cell reproduction.

Rudolf Virchow

German scientist who linked observations of cell division, emphasizing that new cells arise from existing cells.

Nucleus

Cell part controlling activities, chemical reactions, development, and reproduction

Cell Membrane

Outer layer controlling cell contents entering and leaving

Cytoplasm

Jelly-like mixture where cell functions occur

Vacuole

Storage structure in cells containing various substances

Organelles

Structures with specific functions in cells, e.g., mitochondria, lysosomes

Mitochondria

Cell organelles producing energy from food

Lysosomes

Organelles removing wastes from cells

Endoplasmic Reticulum

Forms pathways for materials to move easily within cells

Ribosomes

Microscopic factories producing proteins for growth and repair

Plant Cell Wall

Supportive structure outside the cell membrane in plant cells

Chloroplasts

Organelles in plant cells for photosynthesis, containing chlorophyll

Unicellular Organisms

Living beings composed of a single cell, e.g., bacteria

Mitosis

Cell division process producing two identical cells

Involuntary Muscles

Muscles working automatically, e.g., diaphragm

Cardiac Muscle

Muscle of the heart, involuntary and continuously active

Nerve Cells

Cells transmitting information in the brain and body

Axon

Longest part of a nerve cell, can reach over a meter

Red blood cells

Carry oxygen to cells and remove carbon dioxide

White blood cells

Part of the immune system, fight infections

Brown fat cells

Produce heat for the body, especially in cold

White fat cells

Store energy and provide insulation under the skin

Epithelial tissue

Forms surfaces over organs, e.g., skin and digestive lining

Connective tissue

Supports and holds together other tissues in the body

Muscle tissue

Specialized tissue that can contract, enabling movement

Nerve tissue

Sends electrical signals around the body for communication

Tissues

Specialized cells working together for a specific task

Organs

Contain different tissues working together for a task

Organ systems

Multiple organs working together for a common function

Vascular tissue

Transports materials in plants, composed of xylem and phloem

Xylem

Carries water from roots, provides support to plants

Phloem

Carries glucose from leaves to all plant parts

Photosynthesis

Process by which plants make glucose using sunlight

Chlorophyll

Chemical that converts sunlight into plant energy

Stomata

Regulate gas exchange in leaves, control water loss

Root hairs

Increase surface area for water absorption in plants

Guard cells

Regulate opening and closing of stomata in plant leaves