Brooks Biological Principles Exam 2 Questions and Answers 100% Accurate

Cell Theory -ANSWER_ all living things are composed of cells and come from living cells Robert Hooke -ANSWER_ one of the first to use microscope, observing a piece of cork from the stem of plants, where he found chambers arising in the idea of a cell. Light Microscope -ANSWER_ takes pictures of large atoms. nucleus, not electrons Scanning Electron Microscope -ANSWER_ electrons are reflected off of a specimen and are analyzed by a computer to create a 3D image Transmission Electron Microscope -ANSWER_ Microtome: a tool used to cut extremely *thin* slices of material for observation under a TEM. Microtomes are often made of diamonds Can you see electrons using the electron microscopes? -ANSWER_ No, can only see neutrons & protons Why are most cells small? -ANSWER_ To maximize the ratio of surface area to volume for regulating the internal cell environment Smaller cells have bigger membranes Does cell need a bigger surface area or volume? -ANSWER_ surface area Plasma Membrane -ANSWER_ aka "Fluid Mosaic Model" composed of fluidlike phospholipid bilayer, proteins, cholesterol (*helps maintain proper fluid viscosity*), and glycoproteins (antigens: "name tags" for immune system) "self" antigen: produced by the body "not self" antigen: not produced by the body so antigens will attack this Get sick more when younger because body is still learning these "name tags" Arthritis: autoimmune disease where the body attacks itself Pollen grain: not self, antigens will attack = phagocytosis involved in *ATP production* and the electron transport system Cell Wall -ANSWER_ outside of the cell membrane in some organisms (plants); composed of carbohydrates or carbohydrate derivatives (peptidoglycan for bacteria) Cytoplasm -ANSWER_ material outside the nucleus • site for metabolic activity • cytosol: solution with dissolved substances such as glucose, CO2, & O2, etc • organelles: membrane-bound subunits of cells with specialized functions