Question | Answer |
What is the order of organization of systems? | Cell--tissue--organ--organ system--organism |
Organism | Anything that can live on its own |
Cell | membrane covered structure that contains all the materials necessary for life |
Tissue | a group of cells working together to perform a specific job |
Organ | two or more tissues working together to perform a specific job |
Organ system | group of organs working together (i.e- digestive, respiratory) |
Robert Hooke | Saw first cells in cork |
Anton Van Leewenhoek | first observed living cells in pond water |
Cell theory | a) all organisms are composed of one or more cells
b) cell is the basic unit of life in all living things
c) all cells come from other cells |
Why can't cells be the size of a basketball? (Include volume/surface area in your answer) | Cells are small because the surface is not large enough to bring in enough nutrients or get rid of enough waste to keep cell alive
-Inside (volume) grows faster than the outside (surface area)
-Big or small organisms have the same size of cells |
What are the 2 type of cells? | Eukaryote & Prokaryote |
Prokaryote | No nucleus to contain DNA; it floats around
(i.e- bacteria) |
Eukaryote | Has nucleus which contains DNA
(i.e- animal cells) |
Organelles | little organs of function |
Cytoplasm | jellylike material that surrounds organelles |
What does the cell membrane do? | allows nutrients and waste to move into and out of cell
-made of phospholipids that do not like water so they force the water to go through gated channels
-all cells have cell membrane |
Nucleus | largest organelle; stores DNA |
Nucleolus | in nucleus; stores material used to make ribosomes |
Ribosomes | smallest and most abundant organelle
-amino acids hook together to make proteins |
Ednoplasmic Reticulum | sacks and tunnels of membranes that carry substances to outside of cell
-Found a lot in cells that make proteins, lipids, and enzymes
-Break down chemicals that harm cells |
Types of endoplasmic reticulum | Rough- covered with ribosomes; transport proteins
Smooth- is not covered with ribosomes |
Golgi bodies | flattened stacked membranes
-changes lipids and proteins, pinches them off into sacks (vesicles) and ships them out of the cell
-helps create lusosomes |
Vesicle | membrane bound structure that carries substances from golgi bodies |
Lysosomes | contain digestive enzymes
-breakdown old cells and bacteria
-"garbage trucks" of the cell |
What cells have a lot of lysosomes and why? | White blood cells b/c they attack bacteria, etc. |
Mitochondria | energy is released in this organelle from glucose being broken down
-active organs like muscles have more mitochondria |
Cristae (mitochondria has it) | inner folds that increase the surface area so more glucose can be broken down and more energy (ATP) released |
Plant cells have some organelles that ___________ don't have | animal cells |
Plant cells: cell wall | made of cellulose
-tough and rigid |
Chloroplasts | contain cholorophyll- green pigment; absorb sunlight where photosynthesis occurs and glucose (sugar) is made |
Vacuoles | Sack that contains water, waste material, food
-Makes up most of cells volume |
What are the two basic shapes of cells and what cells are they? | Square- plant cells
usually round- animal cells |
Microscope | -magnifies objects |
Magnification | how much larger a specimen is when using a microscope |
List the 3 types of microscopes in order from least magnified to most magnified | Light microscope, Scanning Electron Microscope, and Transmission Election Microscope |
Light microscope | the models found in most schools, uses compound lenses and light to magnify objects.
-The lenses bend or refract the light, which makes the object beneath them appear closer |
Scanning Electron Microscope | -SEMs do not use light waves; they use electrons (negatively charged electrical particles) to look at surface of object
-Magnify objects up to 500,000X
-If you want to look at the surface you may have to cover the surface by a very thin layer of gold |
Transmission Electron Microscope | aims beam of light through thin slices of specimen
-Thicker pieces appear darker
-Magnifies up to 1,000,000X |
cell membrane- gated channels | protein molecules that create openings to allow H2O or sugar, etc. to enter and leave the cell |