The primary function of the cell's membrane is to: provide support and shape prevent chemicals from entering the cell prevent chemicals from leaving the cell selectively permit or restrict substances from entering or leaving the cell

Which of the following choices is not an effective solution to the energy waste related to inefficient lighting? a. using low-pressure sodium lighting sources b. pointing lights on billboards and street signs upward c. placing light sources on time controls d. shielding light to direct it downward

How do living things obtain phosphorus

How many chromosomes does each human cell contain? a. 23 chromosomes b. 26 chromosomes c. 43 chromosomes d. 46 chromosomes