Concept of Life

• Movement - Most animals move about, but movement from one place to another in itself is not diagnostic of life. The criterion of movement is thus neither Necessary (possessed by all life) nor sufficient (possessed only by life).
• Sensitivity - Almost all living things respond to stimuli. Not all stimuli

  produce responses. This criterion, although superior to the first, is still

  inadequate to define life.
• Death - All living things die, while inanimate objects do not. Death is not easily distinguished from disorder.
• Complexity - All living things are complex. Complexity is a necessary criterion of life, but it is not sufficient in itself to identify living things

  because many complex things are not alive.
• Levels of Cellular Organizations

  • Proton, Neutron, Electron —> Atom —> Molecules —> Organelles —> Cell —> Tissue —> Organ —> Organ System —> Organism —> Population —> Community —> Ecosystem —> Biosphere
• ATP - adenosine triphosphate

  decomposer - detritivores <- consumer - animals, man

  <- producer - plants <- SUN
• Photosynthesis formula

  6CO2 + 6H2O + ( light ) ---> C6H12O6 + O2
• Chromosomes

  Spem - 23

  Eggcells - 23

  Zygote = 46
• Living things have a complex, organized structure

  Cellular Organization
• The hair follicles and various forms of skin receptors and glands are present in the skin layer.

  Living things respond to stimuli
• Pacinian Corpuscle – a receptor that detects "pressure" and vibration.
• Meissner’s Corpuscle – receptors that are sensitive to "touch".
• Ruffini’s End Organ – receptors in the skin that detect "heat".
• Krause’s Bulb – Cold
• Bare Nerve Endings – Pain
• 2 types of Bare Nerve Endings

  • Sweat gland / Sebaceous Gland - (Secretes oil)
• All living things maintain relatively constant internal conditions, different from their environment.

  Homeostasis
• Living things acquire and use materials and energy from their environment and convert them into different forms - metabolism (meta-change) sunlight energy (photosynthesis), and chemical energy
• Living things reproduce themselves through the molecular blueprint called DNA - deoxyribonucleic acid
• Living things maintain their complex structure and their internal environment - homeostasis (stay the same). Ex. body temperature, blood sugar
• Living things GROW