hello everyone welcome to biology I'm mr. Morris and I'll be your instructor for the term how many of you remember your high school biology class did you like it or did you hate it do you remember anything at all well we'll take what you learned in high school and broaden the topic we will cover things from chemistry to cell parts to the whole organism and how they are classified my favorite stuff if you have any questions as you watch the lecture chop them down and email me I'll be sure to reply as soon as I can the prefix bio refers to life and ello Gy refers to the scientific study of so when you put them together you get the scientific study of life but what is life what makes a living thing living we need to look at the five characteristics that make living things living those five characteristics are organization energy responds reproduces and adaptation let's take a look at each one in detail life is organized when you think of your body you should realize just how complicated it is and what it's made of think of an office building how many bricks did it take to make the structure how many atoms did it take to make you the atom is the building block of everything they bond to each other to form molecules and compounds molecules are small and simple like oxygen gas or carbon dioxide compounds are more complex like sugar and proteins when molecules and compounds bond together organelles are formed organelles are tiny organs that have a very specific look and a very specific function similar to your heart or your stomach they have a job to do when organelles come together cells are formed the cell is the smallest living unit of matter I said living because the cell can reproduce all by itself atoms can't and molecules can't when cells come together they form tissues tissues are groups of cells with a specific function every cell in your body belongs to one of these cell types epithelium covers other tissue your skin is epithelium connective tissue connects one tissue to another almost like glue nervous tissue can be excited and stimulated your brain and nerves are composed of nervous tissue muscle tissue is responsible for movement your heart moves the blood and your muscles move your arms as you walk and talk when tissues come together you get the true organ the stomach the liver and the kidney are true organs much more complex than the organelle when organs come together we reach the system level of organization there are 11 body systems all making sure your body's doing what it needs to do when systems come together we have you the most complex organism on the planet but does that make you the most fit probably not but we'll talk about that later on