LEC 1 Biology (1) PDF - Mashreq University

‫بسم هللا الرحمن الرحيم‬ An Introduction to cell biology disteducation.mashreq.edu.sd/  Overview  The Definition of Biology & Divisions  Proprieties of living things  Cell structure and function  The Cell life Cycle - Regulation (cell division)  C...

‫بسم هللا الرحمن الرحيم‬ An Introduction to cell biology disteducation.mashreq.edu.sd/  Overview  The Definition of Biology & Divisions  Proprieties of living things  Cell structure and function  The Cell life Cycle - Regulation (cell division)  Classification Of Organism  Systemic Of Organism  Definition of Biology The word biology is derived from the Greek words bio/ meaning: life and logos meaning: study. Biology : The study of living organisms Biologist : The person who studies Biology biological science : divided into many specialized fields that cover their morphology, physiology, anatomy, behavior…  Divisions of Biology Branches of biology: ▶ Botany: Is the study of plants. ▶ Zoology: Is the study of animals. Sub braches of biology: ▶ Ecology: Study of how organisms interact with their environment & with other organisms. ▶ Physiology: studies the function of body structures. ▶ Anatomy The Defintion Terms: ▶ Anatomy : Greek=to cut up, or dissect The science that deals with the structure of the body. ▶ Gross Anatomy: which can be seen with the naked eye ▶ Microscopic Anatomy: That which can be seen with the assisted eye ▶ Comparative Anatomy: Comparison of structures between the organisms ▶ Developmental Anatomy: The study of anatomical changes in a life cycle ▶ Cytology: The study of cells ▶ Histology: The study of tissues ▶ Organology: The study of organs Living things The characteristics of living things (organisms): 1. Cellular organization 2. Reproduction 3. Metabolism 4. Response to stimuli 5. Growth and development 6. Adaptation 7. Responsiveness 8. Excretion ▶ Metabolism: of all the chemical reactions (anabolism and catabolism) taking place in a cell of living organism. ▶ Responsiveness: All organisms are sensing their environment and respond to various physical, chemical and biological stimuli. ▶ Adaptation: Changes in the structure or behavior of an organism that allow it to survive in a particular habitat. ▶ Growth and development: Young organisms grow and developed into adults ( they can increase cells both in number and mass) ▶ Movement: Animals exhibit a wide range of movements.(change position) E.g.: walking-flying- swimming… ▶ Respiration: Oxygen is used for the oxidation of food and carbon dioxide is produced. (Exchange of respiratory gases) ▶ Excretion: The process by which organisms remove wastes ▶ Reproduction: The biological process by which new organisms (offspring's) are produced from organisms of the same kind.  Cell structure and Function Cellular structure: All living organisms are made up of cells which may be prokaryotic or eukaryotic. ▶ Prokaryotes: are unicellular, lack membrane bound nuclei and some organelles like endoplasmic reticulum, Golgi bodies and so on (Example: Bacteria /Blue and green Algae). ▶ Eukaryotes: a definite nucleus and membrane bound organelles are present. Eukaryotes may be unicellular (Amoeba) or multicellular like? Prokaryotes: Prokaryotes are the smallest and simplest type of cells. Prokaryotes have no true nucleus and no membrane bound organelles. Prokaryotes’ Genome consists of single chromosome. DNA bundles together in a region called the nucleoid. Reproduction is asexual; basically mitosis  Eukaryotes: Eukaryotes are large and complex in structure. Eukaryotes have nuclei and membrane-bound organelles. Eukaryotes’ Genome consists of numerous chromosomes. Reproduction is sexual; by mitosis and meiosis Classification of Organism  Systemic of an Organism ▶ It is a group of organs working together to perform specific functions. The body is divided into biological system such as: 1. Circulatory System 2. Respiratory System 3. Digestive System 4. Nervous System 5. Excretory System Thank You