Biology

• Biology


  The study of living organisms/things
• Fields of study in the biological sciences

  • Zoology: The study of animal life
  • Botany: The study of plant life
  • Ecology: The study of the relationship of living things to their environment
  • Embryology: The study of the formation and development of organisms in their earliest stages of life
  • Anatomy: The study of structures of the body
  • Physiology: The study of the functions of the body
  • Genetics: The study of heredity
  • Cytology: The study of the cell
  • Histology: The study of tissues
  • Bacteriology: The study of bacteria and/or unicellular plant life
• Biology includes biological concepts and process skills, technology and attitudes and values for addressing the needs and problems of society
• In recent years, the development of techniques in genetic engineering and increased understanding of the molecular basis of cellular processes have led to the emergence of a new and exciting field of scientific research called biotechnology
• Cell


  The basic structure of all living things, this is the foundation of cell theory
• Some cells are total living organisms while other cells are the basic units of structure of complex living things
• Most cells can reproduce to form new cells which are almost identical to the original cell
• Sex cells


  Reproduce by meiosis
• Somatic cells (autosomes or body cells)


  Reproduce by mitosis
• Prokaryotic cells


  Cells that do not have a nuclear membrane or membrane-bound organelles
• Prokaryotes


  • Bacteria and blue-green bacteria
• Eukaryotic cells


  Most cells making up all other living organisms
• Components of a generalized cell

  • Cell membrane
  • Nucleus
  • Cytoplasm
• Cell membrane


  A double layer of lipids that surrounds the cell, acting as a "gatekeeper," controlling what moves into and out of the cell
• Nucleus


  Separated from the cytoplasm by a thickened membrane that is more selective than the cell membrane, it is the control center of the cell because it contains all the genetic information
• Cytoplasm


  A semi fluid liquid that fills the cell and holds the components of a cell, dissolved nutrients such as amino acids and sugars, and all the chemicals for that particular cell to carry out its living activities
• Organelles that can be found in a cell

  • Mitochondria
  • Chloroplast
  • Plastids
  • Lysosomes
  • Smooth Endoplasmic Reticulum
  • Rough Endoplasmic Reticulum
  • Golgi Apparatus
  • Peroxisomes
  • Vacuoles
  • Basal bodies
  • Cell wall
  • Centrioles
  • Nucleolus
  • Chromosomes
  • Ribosome
• Mitochondria


  The powerhouse of the cell, the site where energy (ATP) is obtained from food consumed and made available for the use of the cell
• Chloroplast


  The site of photosynthesis
• Plastids


  Store chlorophyll for the use of chloroplasts
• Lysosomes


  Membrane-bound vacuoles in the cytoplasm, which contain hydrolytic enzymes that digest materials entering the cell, with the enzymes in the vacuoles so they don't destroy the cell itself
• Smooth Endoplasmic Reticulum


  Does not have ribosomes attached and is the transportation system of the cell
• Rough Endoplasmic Reticulum


  Has ribosomes attached and also carries out cell transportation, but mainly of necessary protein materials needed by the cell
• Golgi Apparatus


  Manufactures, synthesizes, stores, and distributes hormones, enzymes, and other protein materials needed by the individual cell or by the organism
• Peroxisomes


  Manufacture, store, and secrete oxidation enzymes needed by the cell
• Vacuoles


  Fluid-filled sacs which usually contain water, proteins, pigments, organic acids, or metabolic wastes, some active in cell metabolism, others act as storage containers
• Basal bodies


  Short, cylindrical microtubules which play a role in cell movement by directing the formation of cilia and flagella
• Cell wall


  A nonliving, inflexible, outer component of plant cells which supports and protects the cell, the main component often being cellulose
• Centrioles


  Small cylindrical bodies which lie just outside the nucleus in animal cells in a specialized area of cytoplasm, playing a role in cell division and in cell motility
• Nucleolus


  A dark-straining organelle within the nucleus which contains RNA, proteins, and some DNA, playing a role in the synthesis of ribosomal RNA
• Chromosomes


  Threadlike structures composed mainly of DNA which is arranged in genes, this being the hereditary information of the cell
• Ribosome


  A tiny, grainy structure attached to the endoplasmic reticulum, serving as the protein factory of the cell, containing enzymes to carry out protein synthesis
• Plant cells have most of the same structure as animal cells except for centrioles
• Plant cytoplasm also contains vessels called chloroplasts that capture light energy and use it to make the cell's food
• Plant cells also have a tough cell wall surrounding the cell membrane, the cell wall giving a plant its stiffness
• Although each cell of an individual contains all the genetic information for its form and function, not every cell expresses all the information
• In multicellular organisms, cells develop in different ways as the embryo develops, this unique ability for cellular differentiation allowing development of specialized cellular organelles, cells, tissues, organs, and systems that make each member of a species unique
• Homeostasis


  The balance or working equilibrium that is optimum for the cell's needs, obtained by its internal control, accounting for all movement into and out of the cell
• Though the cell can adjust to a wide range of environmental needs and amounts, there is a limit to how much and how often it can adjust
• Osmosis


  The movement of molecules to meet needed concentrations on either side of the cell membrane, resulting in a state of equilibrium where the cell operates most efficiently