How is a cell membrane different than a cell wall

During which phase does earth see more than half of the moon's surface? 1)first quarter2)third quarter3)waxing gibbous4)waning crescent

Which of the following is an abiotic factor in an ecosystem? a. bacteriab. airc. niched. grass(abiotic=non-living) me !

An adult inhales about 6.0×10−4 m3 of fresh air during a breath. only 20% of fresh air is oxygen. assume the pressure in the lungs is 1.0×105 paand the air is at a temperature of 300 k. how many oxygen molecules are in each breath? a. 1.4x10^23 b. 2.9x10^21 c. 4.9x10^-4 d. 2.9 x10^25