Gen Bio PDF

**1- Cell:** The fundamental unit of life, capable of carrying out all the processes necessary for life. **2- Atom**: The smallest unit of an element that retains the chemical properties of that element. **3- Molecule**: Two or more atoms held together by chemical bonds. **4- Organelle**: A speci...

**1- Cell:** The fundamental unit of life, capable of carrying out all the processes necessary for life. **2- Atom**: The smallest unit of an element that retains the chemical properties of that element. **3- Molecule**: Two or more atoms held together by chemical bonds. **4- Organelle**: A specialized structure within a cell that performs a specific function **5- Robert Hooke**: An English scientist who first observed cells in cork under a microscope in 1665. He coined the term \"cell\" because the compartments he saw reminded him of the small rooms monks lived in. **6- Anton van Leeuwenhoek**: A Dutch scientist who made significant improvements to the microscope and was the first to observe living cells, including bacteria, red blood cells, and sperm cells. **7- Louis Pasteur**: A French scientist who made groundbreaking contributions to microbiology, including disproving spontaneous generation and developing pasteurization, a process used to kill harmful bacteria in food. **8- Matthias Schleiden**: A German botanist who proposed that all plants are composed of cells. **9- Theodor Schwann**: A German physiologist who extended Schleiden\'s theory to animals, establishing the cell theory that states that all living organisms are composed of cells. **10- Rudolf Virchow**: A German pathologist who proposed that all cells arise from pre-existing cells, further solidifying the cell theory. **11- Cytoplasm**: The jelly-like substance that fills the inside of a cell, containing the organelles and other components. **12- Ribosomes**: Small organelles responsible for protein synthesis. **13- Cell membrane**: A thin, flexible barrier that surrounds the cell, regulating what enters and exits. **14- Cell wall**: A rigid outer layer found in plant cells that provides support and protection. **15- Nucleus**: The control center of the cell, containing the genetic material (DNA). **16- Lysosome**: An organelle that contains enzymes that break down waste products and cellular debris. **17- Mitochondria**: The \"powerhouses\" of the cell, responsible for generating energy (ATP) through cellular respiration. **18- Endoplasmic reticulum (ER**): A network of interconnected membranes involved in protein synthesis, lipid synthesis, and detoxification. **19- Vacuole:** A large, fluid-filled sac that stores water, nutrients, and waste products. **20- Chloroplast**: An organelle found in plant cells that carries out photosynthesis. **21- Nucleolus**: A dense region within the nucleus where ribosomes are assembled. **22- Chlorophyll**: The green pigment in plants that absorbs light energy for photosynthesis. **23- Leucoplast**: A colorless plastid that stores starch. **24- Thylakoids**: Flattened sacs within chloroplasts where chlorophyll is located. **25- Stomata**: Pores on the surface of leaves that allow for gas exchange. **26- Cytoskeleton**: A network of protein filaments that provides structural support and helps the cell move. **27- Cilia**: Short, hair-like projections that help with movement. **28- Flagella**: Long, whip-like projections that help with movement. Cell Division: **29- Centromere**: The region where sister chromatids are attached. **30- Chromatids**: Two identical copies of a chromosome that are joined together at the centromere. **31- Gap 1 (G1**): The first stage of interphase, where the cell grows and carries out normal metabolic processes. **32- Synthesis Phase (S):** The stage of interphase where DNA is replicated. **33- Gap 2 (G2**): The second stage of interphase, where the cell continues to grow and prepares for mitosis. **34- Mitosis**: The process of cell division that produces two daughter cells genetically identical to the parent cell. **35- Meiosis**: The process of cell division that produces four daughter cells, each with half the number of chromosomes as the parent cell.- Cytokinesis: The division of the cytoplasm after mitosis or meiosis. **36- Apoptosis**: Programmed cell death, a controlled process that eliminates damaged or unnecessary cells. **37- Process of Interphase**: The period between cell divisions, where the cell grows and replicates its DNA. **38- Process of Meiosis:** The process of cell division that produces gametes (sperm and egg cells). **39- Process of Mitosis:** The process of cell division that produces two identical daughter cells. **40- Polyploidy**: The condition of having more than two sets of chromosomes. **41- Aneuploidy**: The condition of having an abnormal number of chromosomes. **42- Nondisjunction**: The failure of chromosomes to separate properly during cell division. **43- Cell cycle:** The series of events that take place in a cell from its formation to its division. **44- Passive transport**: The movement of molecules across a membrane without the use of energy. **45- Simple diffusion**: The movement of molecules from an area of high concentration to an area of low concentration without the assistance of a membrane protein. **46- Facilitated diffusion**: The movement of molecules across a membrane from an area of high concentration to an area of low concentration with the assistance of a membrane protein. **47- Osmosis**: The movement of water molecules across a semipermeable membrane from an area of high water concentration to an area of low water concentration. **48- Isotonic**: A solution that has the same concentration of solutes as the cell. **49- Hypertonic**: A solution that has a higher concentration of solutes than the cell. **50- Hypotonic**: A solution that has a lower concentration of solutes than the cell. **51- Tonicity**: The ability of a solution to cause water to move into or out of a cell. **52- Active transport**: The movement of molecules across a membrane against their concentration gradient, requiring energy. **53- Endocytosis:** The process by which cells take in substances from their surroundings by forming vesicles. **54- Phagocytosis**: The process by which cells engulf large particles. **-55 Exocytosis**: The process by which cells release substances from their surroundings by forming vesicles. **56- Transcytosis**: The process by which cells transport substances across their membrane using vesicles. **57- Monosomic**: The condition of having one copy of a particular chromosome. **58- Trisomy**: The condition of having three copies of a particular chromosome.