Question

biology 1 eoc assessment sample questions

1. water is essential for life. its special properties make water the single most important molecule in plant life. which of the following properties of water enable it to move from the roots to the leaves of plants?

a water expands as it freezes.
b water is an excellent solvent.
c water exhibits cohesive behavior.
d water is able to moderate temperatures.

1. an osmosis investigation was conducted using chicken eggs to represent cells with semipermeable membranes. the mass of each egg was measured to determine how much water diffused into or out of the eggs. the eggs were first soaked in vinegar to dissolve the shell. each egg was then placed in one of three different solutions for 24 hours. the table below shows the results of the investigation.

osmosis in cells

solution	average mass of eggs before soaking (grams)	average mass of eggs after soaking (grams)	difference in average mass (grams)	percent change in average mass
corn syrup (5% water)	98.6	64.5	34.1	-34.6
distilled water (100% water)	64.5	105.3	40.8	+63.3

based on this experiment, which of the following should be inferred about cells with semipermeable membranes?
a substances other than water may also cross the cell membrane.
b substances other than water may block pores in the cell membrane.
c water enters the cell when placed in environments of high water concentration.
d water leaves the cell when placed in environments with a low concentration of solutes.

Explanation:

For question 2, water's cohesive behavior allows it to move from roots to leaves through xylem vessels in plants via capillary action. For question 3, when eggs (representing cells with semi - permeable membranes) are in distilled water (high water concentration), water enters the eggs causing an increase in mass, showing that water enters the cell when placed in environments of high water concentration.

Answer:

1. C. Water exhibits cohesive behavior.
2. C. Water enters the cell when placed in environments of high water concentration.