Question | Answer |
levels of organization
atomic level | atoms are defined as the smallest unit of an element that still maintains the property of that element
ex. carbon, hydrogen, oxygen |
levels of organization
molecular level | atoms combine to form molecules which can have entirely different properties than the atoms they contain
ex. water, DNA, carbohydrates |
levels of organization
cellular level | cells are the smallest unit of life. cells are enclosed by a membrane or cell wall and in multicellular organisms often perform specific functions
ex. muscle cell, skin cell, neuron |
levels of organization
tissue level | tissues are groups of cells with similar functions
ex. muscle, epithelial, connective |
levels of organization
organ level | organs are two or more types of tissues that work together to complete a specific task
ex. heart, liver, stomach |
levels of organization
organ system level | an organ system is group of organs that carries out more generalized set of functions
ex. digestive system, circulatory system |
levels of organization
organism level | an organism has several organ systems that function together'
ex. human |
prokaryotes | -single-celled organisms that lack internal structures surrounded by membranes
-lack a true nucleus
ex. bacteria, archaea |
eukaryotes | -single-celled and multi--cellular organisms that have cells containing internal, membrane-bound structures
-have a true nucleus containing the cell's DNA |
unlike prokaryotic cells, eukaryotic cells have the capacity to... | assemble into multi-cellular organisms |
inside eukaryotic cells are membrane-bound structures called... | organelles |
what are life's levels of organization? | atom, molecule, organelles, cell, tissue, organ, organ system, organism, population, community, ecosystem, biome, biosphere |
why is water a polar molecule? | -because the oxygen side is slightly negative and the hydrogen side is slightly positive
-the three atoms are constantly at a tug of war for their electrons
-polarity helps water to bind with other substances |
cohesion | water tends to stick together
ex. droplets of dew on grass |
surface tension | the top layer of water is very strong
ex. insects can walk on water |
adhesion | water tends to stick to OTHER things
ex. water sticks to glass after washing |
capillary action | movement of water against gravity
ex. allows water to rise narrow tubes in plant stems |
high specific heat | water is able to resist changes in temperature
ex. helps organisms retain body heat and resist freezing in cold temps |
universal solvent | water can dissolve many things
ex. putting sugar in tea |
solvent | the material that is doing the dissolving |
solute | the material that is dissolved |
hydrophobic | not mixing with water |
hydrophilic | mixing with water |
density | the degree of compactness of substance
ex. ice is less dense than water |
which statement best describes an effect of the low density frozen water in a lake? | when water in a lake freezes, it floats, providing insulation for organisms below |