Cells

Cells are the basic structural and functional units of all living organisms. They are often referred to as the "building blocks of life" because all living things are composed of one or more cells.

Types of Cells

There are two main types of cells: prokaryotic and eukaryotic cells.

Prokaryotic Cells

• Prokaryotic cells are simple, primitive cells that do not have a distinct nucleus or membrane-bound organelles.
• They are typically found in bacteria and archaea.
• Prokaryotic cells have a single circular DNA molecule located in the nucleoid region.

Eukaryotic Cells

• Eukaryotic cells are more complex cells that contain a true nucleus and membrane-bound organelles.
• They are found in plants, animals, fungi, and protists.
• Eukaryotic cells have multiple linear DNA molecules located within the nucleus.

Cell Structure

Eukaryotic cells have a complex structure with various organelles that perform specific functions.

Nucleus

• The nucleus is the control center of the cell and contains the genetic material (DNA).
• It is surrounded by a double membrane called the nuclear envelope.

Cell Membrane

• The cell membrane, or plasma membrane, surrounds the cell and regulates the passage of substances in and out of the cell.
• It is composed of a lipid bilayer with embedded proteins.

Organelles

• Eukaryotic cells contain various organelles, such as the endoplasmic reticulum, Golgi apparatus, mitochondria, chloroplasts (in plant cells), and lysosomes, each with specific functions.

Cell Functions

Cells carry out a variety of functions that are essential for the survival of the organism.

Metabolism

• Cells carry out metabolic processes such as respiration, photosynthesis (in plant cells), and synthesis of biomolecules.

Reproduction

• Cells have the ability to reproduce and give rise to new cells through processes such as mitosis and meiosis.

Homeostasis

• Cells maintain a stable internal environment through processes such as osmoregulation and waste elimination.

Cell Theory

The cell theory is a fundamental concept in biology that describes the properties of cells:

1. All living organisms are composed of one or more cells.
2. The cell is the basic unit of structure and function in organisms.
3. All cells come from pre-existing cells through the process of cell division.

Summary

Cells are the basic units of life, with different types and structures that enable them to carry out essential functions. Understanding the properties of cells is crucial for comprehending the biology of living organisms.

[Cells] Related Worksheets and Study Guides:

• Cell processesBiology • High School
• Cell ReproductionBiology • High School