Biology

• Light Microscopy


  A microscopy technique that uses light to magnify samples.
• Electron Microscopy


  A microscopy technique that uses an electron beam to scan and create an image.
• Resolution


  The smallest distance between two points that can be seen as separate.
• Field of View (FOV)


  The area visible under the microscope.
• Depth of Field


  The distance within which objects are in focus.
• Convex Lenses


  Lenses in the microscope that gather and focus light on the sample.
• Scanning Electron Microscope


  A type of electron microscope that uses a focused beam of electrons to produce a high-resolution image.
• Transmission Electron Microscope


  A type of electron microscope that uses a thin beam of electrons to produce a high-resolution image.
• Reflection Electron Microscope (REM)

   Uses scattered high-energy electrons falling on a surface at glancing angles to generate an

  image of the surface.

   This type of microscope usually has two magnification characteristics: magnification in

  the electron beam incidence plane and magnification in the plane perpendicular to the

  incidence plane
• Immersion Oil


  A clear, colorless liquid used to improve microscopic specimen clarity by reducing light refraction and scatter
• Immersion Oil Properties


  Diverse properties of immersion oil, including refraction, scattering, and chemical inertness
• Prokaryotes


  Microorganisms without a true nucleus and membrane-bound organelles, such as bacteria and Archaea
• Eukaryotes


  Organisms with a true nucleus and membrane-bound organelles, such as protists, animals, plants, and fungi
• Prokaryote Cell Structure


  Prokaryotes have a simple cell structure with a cell membrane and cytoplasm containing genetic material
• Eukaryote Cell Structure


  Eukaryotes have a complex cell structure with a true nucleus and membrane-bound organelles, such as mitochondria and chloroplasts
• Prokaryote Reproduction


  Prokaryotes typically reproduce through binary fission, conjugation, or budding
• Eukaryote Reproduction


  Eukaryotes reproduce through mitosis or meiosis
• Fertilization


  The process by which a sperm fertilizes an egg, resulting in the formation of a zygote
• Cleavage


  The process by which the zygote undergoes multiple cell divisions without significant growth, resulting in a ball of cells called a blastula
• Gastrulation


  The process by which the blastula stage forms, with the cells rearranging to create the three primary germ layers (ectoderm, endoderm, and mesoderm)
• Blastula


  A stage in embryonic development characterized by a cavity surrounded by cells
• Zygote


  The result of fertilization, containing a complete set of chromosomes
• Embryonic Development


  The series of changes an embryo undergoes as it becomes a foetus
• Embryogenesis


  Development of an embryo
• Zygote


  The first stage of life, starts after the fusion of egg and sperm (male and female gamete)
• Embryogenesis


  1. Zygote division

  2. Embryo formation
• Embryo stage


  Ends after 8 weeks of pregnancy, organs form in this stage
• Foetus stage


  Begins after 8 weeks of pregnancy, skeleton system forms in this stage
• Gastrulation


  Stage in which cell movements result in a massive reorganization of the blastula into three layered structure known as the gastrula
• Gastrulation


  1. Differentiation of the gastrula into the three germ layers

  2. Results in ectoderm, mesoderm, and endoderm

  3. Involves changes in cell motility, cell shape, and cell adhesion

  4. Creates a blastopore which is the opening to the archenteron

  5. Archenteron is the invagination of mesoderm and endoderm cells that will later become the digestive tract
• Mesoderm


  Forms via differentiation of the endodermal cells that cover the dorsal region of the archenteron
• Neurula stage


  In embryogenesis, the ectoderm differentiates into neural tissues (nervous tissues)
• Nutrition is the process of providing food to the body cells for health and development

  (growth).

   Plants, bacteria, fungi, protists and animals, all need a constant supply of energy to survive

  and reproduce.

   They get their energy from food.

   Every organism has a nutrition method adapted to its lifestyle.
• Plants and animals


  Have different processes of obtaining food (energy)
• Plants and some bacteria

  • Have chlorophyll (green pigment) to help them make their own food
• Animals, fungi and other bacteria

  • Depend on plants and other organisms for food
• Modes of nutrition


  • Autotrophic
  • Heterotrophic
• Autotrophic nutrition


  The process by which green plants manufacture their own food by converting solar energy (sunlight) into chemical energy (food)
• Heterotrophic nutrition


  The process whereby organisms that cannot make their own food obtain their food (energy) either directly or indirectly from plants or other organisms
• Autotrophs


  Organisms that are capable of making their own food using the solar energy (sunlight) into chemical energy (food)