Lesson 1: Cell Theory PDF

Lesson 1 : CELL THEORY OPENING PRAYER Dear Lord and Father of all, Thank you for today. Thank you for ways in which you provide for us all. For Your protection and love we thank you. Help us to focus our hearts and minds now on what we are about to learn. Inspire us by Your Holy Spirit as we list...

Lesson 1 : CELL THEORY OPENING PRAYER Dear Lord and Father of all, Thank you for today. Thank you for ways in which you provide for us all. For Your protection and love we thank you. Help us to focus our hearts and minds now on what we are about to learn. Inspire us by Your Holy Spirit as we listen and write. Guide us by your eternal light as we discover more about the world around us. We ask all this in the name of Jesus. Amen…  WHAT ARE THE CHARACTERISTICS OF A LIVING ORGANISM? 4  ▪ is the scientific study of life in all of its diverse forms. ▪ Biologists study not only life’s diversity but also the characteristics that are shared by all living organisms. ▪ These characteristics include Biology ❑ levels of organization, ❑ the ability to acquire materials and energy, ❑ the ability to maintain an internal environment, ❑ the ability to respond to stimuli, ❑ the ability to reproduce and develop, and the ability to adapt and evolve to changing conditions THE STUDY OF BIOLOGY AS THE SCIENCE OF LIFE…… Exploring Levels of Biological Organization CELL LESSON 1 : CELL THEORY Learning Competency: ▪ The learners shall be able to explain the postulates of the cell theory ▪ (STEM_BIO11/12-Ia-c-1) LESSON 1 : CELL THEORY CELL ▪ life's fundamental unit of structure and function. ▪ A cell is the smallest entity that can exhibit all characteristics of life. ▪ Some organisms, such as amoebas and most bacteria, are single cells. ▪ Other organisms, including plants and animals, are multicellular. CELL ▪ Human body consists of trillions of microscopic cells of many different kinds, such as muscle cells and nerve cells, which are organized into the various specialized tissues. Early Microscopy and Observations Robert Hooke (1665) → a physicist and curator of instruments for the Royal Society of London, examined the structure of thinly sliced cork under the microscope and described small rectangular compartments which he called cellulae (Latin for small chambers written in his treatise Micrographia) Anton van Leeuwenhoek (1676) a Dutch shopkeeper, examined pond water sample and saw living organisms (protozoa and fungi), which he called animalcules (small animals). His single-lenses magnified an image 200 times. Anton van Leeuwenhoek's pioneering work in microscopy laid the foundation for the field of microbiology. His observations paved the way for further research into the diversity and significance of microorganisms, eventually leading to the development of the cell theory. Development of the Cell Theory The formulation of this theory is given to German scientists: a. Matthias Schleiden,(1838) a German Botanist, stated that all plants are composed of cells b. Theodor Schwann (1839), a German Zoologist concluded that all animals are composed of cells Jointly, Schleiden and Schwann came out with the theory that all living things are composed of cells. c. Rudolf Virchow (1858), ▪ a German Biologist theorized that all living things come from pre-existing living cells. The Cell Theory states: ▪ 1. All known living things are made up of one or more cells. ▪ 2. The cell is the structural and functional unit of all living things. ▪ 3. All cells come from pre-existing cells by division. (Spontaneous generation does not occur). (1) All known living things are made up of one or more cells. This postulate asserts that all living things, whether they are plants, animals, fungi, or microorganisms, are made up of one or more cells. Cells are the basic building blocks of life. (2) The cell is the structural and functional unit of all living things. According to the cell theory, the cell is the smallest structural and functional unit of an organism. All the activities and functions of life occur within cells, and they are the smallest entities that can carry out the processes necessary for life. (3) Cells arise from pre-existing cells This postulate states that new cells are formed through the process of cell division, and they are derived from pre-existing cells. This principle, often attributed to Rudolf Virchow, challenged the earlier idea of spontaneous generation, which suggested that life could arise from non-living matter.  The 1. Cells contain hereditary information which is passed from modern cell to cell during cell division. version of the Cell 2. All cells are basically the same Theory in chemical composition. includes the ideas 3. All energy flow (metabolism and that: biochemistry) of life occurs within cells. Cell Biology is a branch of biology that studies the structure, function, and behavior of cells. Cytology is the exam of a single cell type, as often found in fluid specimens. the study of the structure and function of cells; the examination of cells under a microscope as used in the diagnosis of cancer. CAREER CONNECTION Cytotechnologist ▪ stains the cells from the uterine cervix → medical lab ▪ study cells via microscopic examinations and other laboratory tests.