Sodium and potassium ion channels have several negatively charged residues at the entry to the channel. on what basis do k+ channels specifically select for k+ ions? (in other words, why dont k+ channels enable na+ ions to cross the membrane? )
a. ionic radius, na+ is to smallb. energy cost, it is to energetically costly to dehydrate na+c. charge, na is slightly more electronegative than k and does not interact with the channel carbonyl groupsd. charge, na is slightly less electronegative than k and does not interact with the channel carbonyl groupse. ionic radius, na+ is too big

Can you identify which of the following groups of organisms are, or are not, populations? a. the american bison (bison bison) and grey wolves (canis lupus) currently living in yellowstone national parkb. all of the rainbow trout (oncorhynchus mykiss that) that have ever lived in lake eriec. the group of american bison (bison bison) currently living in yellowstone national parkd. a group of calliope hummingbirds (selasphorus calliope) and a group of rufous hummingbirds (selasphorus rufus) living in the same new hampshire woodse. the northern cardinals (cardinalis cardinalis) living on opposite shores of lake champlain f. all of the whales currently living in the atlantic ocean off cape cod, massachusetts

In which terrestrial biome can you find trees that produce cones instead of flowers and needles instead of leaves? have trees that produce cones instead of flowers and needles instead of leaves. the latitudes in this biome have evenly distributed precipitation throughout the year. is it high or low

Which must be kept in mind when determining if an explanation is correct? check all that apply.which must be kept in mind when determining if an explanation is correct? check all that apply.