Bio 1st sem

• Biology


  The study of life, encompassing organisms ranging from visible animals and plants to microscopic entities
• Properties of Life


  • Cellular Organization
  • Reproduction
  • Metabolism
  • Responsiveness
  • Heredity
  • Homeostasis
  • Growth and Development
• Main Themes in Biology

  • Cellular Structure and Function
  • Reproduction
  • Metabolism
  • Homeostasis
  • Heredity
  • Evolution
  • Interdependence
• Cellular Structure and Function

  All living things are made of cells, which are the smallest units capable of life functions
• Reproduction


  The process of making more of one's own kind, crucial for species survival
• Metabolism


  Chemical reactions in organisms for energy generation and use, often starting with sunlight
• Homeostasis


  Organisms' ability to maintain stable internal environments despite external changes
• Heredity


  Transfer of traits from parents to offspring through genes and DNA
• Evolution


  Changes in inherited properties of species over generations, leading to diversity
• Interdependence


  Ecological interactions among organisms and their environment, highlighting mutual dependence for survival
• Biologists are promoting sustainable practices to preserve natural resources, such as using waste products for livestock feed and energy production, and implementing conservation efforts
• Genetic engineering has led to the development of crop plants resistant to pests and herbicides, with improved nutritional content. For example, enhancing rice with iron and vitamin A to improve diets
• The sequencing of the human genome has provided a roadmap for medical research, aiding in the understanding of genetic diseases and potential treatments
• Genome


  The complete genetic material in an individual, and the human genome contains 3 billion individual units
• Biologists have made progress in combating diseases like AIDS through the development of vaccines that target multiple parts of the virus. Cancer treatments have also improved, with early detection and targeted therapies
• Emerging diseases, like West Nile virus and Mad Cow disease, are being studied to understand their transmission and develop preventive measures
• Gene therapy has shown promise in treating genetic disorders like cystic fibrosis, hemophilia, and muscular dystrophy by replacing defective genes with healthy ones
• Observation


  The foundation of scientific research, involving the use of senses to note and perceive objects or phenomena
• Stages of Scientific Investigations

  • Collecting Observations
  • Asking Questions
  • Forming Hypotheses and Making Predictions
  • Confirming Predictions
  • Drawing Conclusions
• Hypothesis


  An educated guess or explanation based on existing knowledge, which can be tested through experiments or further observations
• Theory


  A well-supported scientific explanation that provides useful predictions but is not absolute and can be revised or rejected based on new evidence
• Before publication, scientific reports undergo peer review to ensure the study was conducted rigorously and the conclusions are supported by the data
• Atom


  The smallest unit of matter, composed of neutrons and protons in the nucleus, and electrons in the electron cloud
• Element


  A pure substance composed of only one type of atom, represented by a symbol
• Isotope


  Atoms of the same element with different numbers of neutrons
• Types of Chemical Bonds

  • Covalent Bonds
  • Ionic Bonds
  • Hydrogen Bonds
• Covalent Bond


  A chemical bond formed by the sharing of electrons between atoms
• Ionic Bond


  A chemical bond formed by the attraction between positively and negatively charged atoms (ions)
• Hydrogen Bond


  A weak attraction between polar molecules, such as water, due to an unequal distribution of charge
• 70% of the human body is composed of water, highlighting its importance in cellular activities and nutrient transportation
• Cohesion


  The attraction between substances of the same kind, leading to surface tension and the formation of drops
• Adhesion


  The attraction between substances of different kinds, enabling capillary action
• Aqueous Solution


  A solution formed when substances dissolve in water
• Polarity


  The unequal distribution of charge in a molecule, allowing it to dissolve polar molecules and ionic compounds, but not nonpolar molecules like oil
• Acid


  A substance that releases hydrogen ions when dissolved in water
• Base


  A substance that reduces the concentration of hydrogen ions in a solution
• pH Scale


  A measure of the acidity or basicity of a solution, with pure water being neutral (pH 7), acidic solutions having a pH below 7, and basic solutions having a pH above 7
• Organic Compound


  A compound in the body composed of carbon atoms bonded to other elements like oxygen and hydrogen
• Types of Carbohydrates


  • Monosaccharides (simple sugars)
  • Disaccharides (two sugar molecules)
  • Polysaccharides (multiple sugar molecules)
• Examples of Carbohydrates


  • Glucose
  • Sucrose
  • Starch