U2L2: Characteristics of Life

• properties shared by all living things passed down over billions of years from the first organisms to have evolved on earth
• the following are considered in the study of life:

  cellular organization, metabolism, homeostasis, reproduction, heredity
• all cells have the same basic structure
• this encloses the cell and controls materials that move in and out


  membrane
• this is known as internal fluid, where organelles are suspended

  cytoplasm
• this contains the hereditary genes called dna


  nucleus
• these organisms are made up of only one cell


  unicellular
• these organisms are made up of many cells


  multicellular
• all living things use energy; everything done requires energy: moving, growing, thinking

  metabolism
• this is captured by plants and algae to convert it to food

  energy
• for the consumer to get the energy, plants or plant eating animals are consumed. it is then converted into useful energy but only 10 percent will be obtained, considering the 10 percent rule
• the sum of all chemical processes that maintain the living state of an organism

  metabolism
• all organisms use energy to grow -> all organisms transport energy from one place to another within cells -> using the special energy carrying molecules called...

  atp (adenosine triphosphate)
• all living things maintain stable internal condition

  homeostasis
• a process where organisms act to keep their interior conditions relatively constant as environment varies alot

  homeostasis
• the human body, however hot or cold the weather may be, maintains an internal temperature of what?


  celsius: 37 c; fahrenheit: 98.5 f
• all living things reproduce

  reproduction
• involves the transfer of genetic information from parents to offspring


  reproduction
• two types of reproduction

  asexual, sexual
• type of reproduction that produces offspring that are genetically identical to a single parent


  asexual
• type of reproduction that involves the parents contributing genetic information to produce a unique offspring


  sexual
• genetic system that is based on the replication and duplication of this long molecule

  dna (deoxyribonucleic acid)
• the information that determines what an individual organism will be like is written in a code dictated by sequence of the dna molecule
• this is each set of instruction within the dna


  gene
• dna is faithfully copied from one generation to the next. any change in gene is also preserved and passed on to the future generations
• the transmission of characteristics from parent to offspring

  heredity
• level of organization

  - hierarchy of increasing complexity within cells, from the:

  
  

  • molecular level of dna - where the chemistry occurs
  • organelle level - where cellular activities are organized
  • cellular level - ... (to) the smallest level of organization
• energy is used by organisms to grow and do work, without it, life stops
• the source of almost all energy

  sun
• plants captures energy from sunlight, use it to make complex molecules by photosynthesis. molecules then serve as a source of fuel for animals that eat plants
• flow of energy among organisms helps determine how organisms interact within their environment
• this is how all kinds of organism came into existence

  evolution
• life forms are changing and have apparently been changing

  evolution
• the theory of evolution by natural selection was proposed by charles darwin. it presumes that organisms with more favorable traits -> would be more likely to survive and reproduce in certain environments
• this is the gaining of favorable trait. like a cactus adapting to a desert environment

  adaptation
• organisms that lack the necessary adaptations would die out and all individuals with favorable adaptations would live on. this causes species to change over time, because of natural selection
• living things interact with each other and with the environment

  interacting systems
• living community is highly structured and interdependent. interdependence is the result of the long process of evolution. like fungi helping plants move from water to land
• coevolution of flowering plants and insects has been responsible for the diversity of both species
• relationship exists between structure and function at all levels of biological organization. structure is ALWAYS related to function