bio 3

Question 1

all living organisms require ___ more than any other substance

Answer 1

water

Question 2

earth is ___% water

Answer 2

70

Question 3

cells are __% -__% water

Answer 3

70-95

Question 4

the water molecule is a ___ molecule

Answer 4

polar

Question 5

water molecules readily form ___ bonds with other polar molecules

Answer 5

Hydrogen

Question 6

water is sticky because?

Answer 6

of its hydrogen bond

Question 7

define cohesion

Answer 7

water sticking to water

Question 8

define adhesion

Answer 8

water attracted to another substance

Question 9

cohesion and adhesion can transport water against ___

Answer 9

gravity

Question 10

why does ice float in water

Answer 10

beacuse hydrogen bonds in ice are more ordered making ice less dense then water

Question 11

since ice floats, when it gets cold, the upper layer of the ice will _____ the lower layers allowing life to survive

Answer 11

insolate

Question 12

define a solution

Answer 12

liquid that is a mixture of substances

Question 13

a hydrophilic substance is water ___

Answer 13

loving

Question 14

a hydrophobic substance is water ___

Answer 14

fearing

Question 15

what does the pH scale describe?

Answer 15

whether a solution is acidic of basic

Question 16

pure water has equal amounts of:

Answer 16

hydrogen ions and hydroxide ions

Question 17

most biological fluids are within pH -

Answer 17

6-8

Question 18

what happens if pH decreases or increases beyond a safe range?

Answer 18

cell processes will no longher function properly

Question 19

what is acid precipitation?

Answer 19

rain, snow or fog which has a lower pH than 5.6