BIOL 121 Midterm: Ecology.docx
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BIOL 121 Full Course Notes
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* keep in mind that theory is an explanation for a very general class of phenomena or observation. The cell theory emerged after some 200 years of work. In 1665 robert hooke used a crude microscope (30x) to examine the structure of a cork from an oak tree. This allowed him to see small, pore-like components soon called to be cells. Soon after, anton van leeuwenhoek succeeded in developing a much more powerful microscope (300x) and observed samples of pond water. Leeuwenhoek was able to view single-celled organisms (i. e. paramecium). He was also able to observe and describe the structure of human blood cells and sperm cells. By the early 1800s, enough data had accumulated for a biologist to claim that all organisms consist of cells. The smallest organisms known today are bacteria, which are barely 200nm wide. In contrast, sequoia trees can be over 100m tall.
