> What is the Cell Theory?
> Identify six key scientists who contributed to the formulation of the Cell Theory (Give their key contributions)
* Explain the postulates of the Cell Theory and give some examples
> What is a cell?
• Identify cell organelles that cannot be found in animals but are present in plant cells and vice versa
Answer (1)
Cell Theory is a fundamental concept in biology that describes the properties and functions of cells. It is based on three main postulates:1. All living organisms are composed of one or more cells: This means that the cell is the basic unit of life.2. The cell is the basic unit of structure and organization in organisms : Cells are the smallest units that carry out all functions necessary for life.3. All cells arise from pre-existing cells : New cells are produced by the division of existing cells.Six Key Scientists Who Contributed to the Cell Theory:1. Robert Hooke (1665): First observed and coined the term "cell" after examining cork cells under a microscope.2. Anton van Leeuwenhoek (1670s): Improved the microscope and observed living cells, including bacteria and protozoa.3. Matthias Schleiden (1838): Proposed that all plants are made up of cells, contributing to the cell theory.4. Theodor Schwann(1839): Extended the cell theory to animals, stating that all animals are made of cells.5. Rudolf Virchow (1855): Introduced the idea that all cells come from pre-existing cells, completing the cell theory.6. Ludwig Traube (1850s): Contributed to the understanding of cell function and development.Examples Illustrating the Postulates of the Cell Theory:- All Living Organisms Composed of Cells: Bacteria, plants, and animals are all made up of cells. For instance, a tree (a plant) consists of millions of plant cells working together.- Basic Unit of Structure and Organization: The human body is made up of various cell types like muscle cells, nerve cells, and epithelial cells, each specialized for different functions.- All Cells Arise from Pre-Existing Cells : During human development, a single fertilized egg cell divides repeatedly to form the trillions of cells in the adult body.What is a Cell?A cell is the smallest unit of life that can perform all essential life processes. Cells are the building blocks of all living organisms.Cell Organelles Unique to Plant or Animal Cells:- Plant Cells: - Chloroplasts: Contain chlorophyll and are involved in photosynthesis. - Cell Wall: Provides structural support and protection, made of cellulose. - Large Central Vacuole : Stores nutrients, waste products, and helps maintain turgor pressure.- Animal Cells: - Lysosomes: Contain digestive enzymes to break down waste materials and cellular debris. - Centrioles: Involved in cell division, specifically in the formation of spindle fibers.
