zoology

• Major elements commonly found in biomolecules

  • Sulfur (S)
  • Phosphorus (P)
  • Oxygen (O)
  • Nitrogen (N)
  • Carbon (C)
  • Hydrogen (H)
• Biogeochemical cycles


  Processes of recycling the earth's limited resources
• Types of biogeochemical cycles

  • Gaseous cycles (carbon, oxygen, nitrogen, water)
  • Sedimentary cycles (sulfur, phosphorus, rock)
• Carbon cycle


  1. Plants use carbon dioxide and sunlight for photosynthesis

  2. Decomposition releases CO2 into atmosphere

  3. Respiration exchanges gases

  4. Combustion produces CO2 and water
• Nitrogen cycle


  1. Nitrogen fixation

  2. Nitrification

  3. Assimilation

  4. Ammonification

  5. Denitrification
• Phosphorus cycle


  1. Weathering and erosion

  2. Absorption by plants

  3. Absorption by animals

  4. Return to environment through decomposition

  
• Sulfur cycle


  1. Release into atmosphere by weathering

  2. Conversion to sulfates

  3. Assimilation and decomposition

  4. Fossil fuel
• Oxygen cycle


  1. Plants release oxygen during photosynthesis

  2. Animals and plants breathe in oxygen

  3. Plants create oxygen, animals release carbon dioxide
• Hydrogen/water cycle


  1. Evaporation

  2. Evapotranspiration

  3. Condensation

  4. Precipitation
• The most abundant gas in the atmosphere is Nitrogen
• Bacteria are organisms that break down dead plants and animals and release nitrogen back into the atmosphere
• Hydrogen or water cycle is a process by which water travels through the environment and organisms
• Photosynthesis is the process where carbon is transformed into chemical energy
• Ammonia is converted to nitrite then nitrate in a process known as Nitrification
• Greenhouse gases such as carbon dioxide trap heat in the Earth's atmosphere causing global warming
• Biogeochemical cycle


  The movement of matter through the biotic (biosphere) and abiotic (geosphere, atmosphere and hydrosphere) environment
• Living things need nitrogen to make proteins and amino acids
• The atmosphere contains the smallest amount of phosphorus in the phosphorus cycle
• Living organisms, plants and animals, is where cellular respiration occurs on the carbon cycle
• The Sun warms the ocean's surface, causing liquid water to evaporate, and it is the main energy source, or the motive force, of the movement of water between reservoirs
• Cell cycle


  The series of events that take place in a cell, resulting in the duplication of DNA and division of cytoplasm and organelles to produce two daughter cells
• Mitosis


  • A process of cell duplication, in which one cell divides into two genetically identical daughter cells
  • Occurs in most cells for growth, repair, and maintenance

  
• Meiosis


  • The type of cell division for the production of gametes and sex cells in sexual reproduction
  • Involves the fusion of gametes from two parents to create offspring with genetic diversity

  
• Cell cycle stages


  1. G1 phase (cell growth)

  2. S phase (DNA replication)

  3. G2 phase (preparation for division)

  4. M phase (mitosis and cytokinesis)
• Stages of mitosis


  1. Prophase

  2. Metaphase

  3. Anaphase

  4. Telophase (and cytokinesis)

  
• Mitosis helps in the replacement of damaged tissues and plays an important role in the life cycle of most living things
• Mitosis occurs in eukaryotic cells, while meiosis occurs for the production of gametes

  
• Mitosis is required for asexual reproduction, vegetative propagation in plants, and the repair and regeneration of damaged tissues

  
• Stages of meiosis


  1. Meiosis I: Prophase I, Metaphase I, Anaphase I, Telophase I

  2. Meiosis II: Prophase II, Metaphase II, Anaphase II, Telophase II

  
• DNA


  A molecule in almost all cells that contains genetic information determining an organism's characteristics
• Nucleus


  The cell's control center
• Chromatids


  Exact copies of a set of chromosomes that form a pair
• Chromosome


  A DNA molecule that has all or part of the genetic material of an organism
• Somatic cell


  Any body cell except the reproductive (germ) cell
• Interphase


  The longest phase in the cell cycle
• Cell division


  The process by which cells are divided into two new daughter cells
• Spindle fibers


  Protein fibers that assist in the separation of chromatids during mitosis
• Haploid cell


  Contains only one set of chromosomes (23)
• Diploid cell


  Contains two sets of chromosomes (46)
• Centrioles


  Paired barrel-shaped organelles that determine the locations of the nucleus and other organelles within the cell