Which of these cells of the dermal tissue of plants prevent water loss and control gas exchange?
a. phloem cells
b. companion cells
c. parenchyma cells
d. guard cells. user: when a plant grows as mediated by growth hormones, which main plant organs are at work

How do tides affect the organisms living in intertidal zones? a. no organisms live in intertidal zones due to the tumultuous environment. b. the mechanical forces of the waves keeps the organisms clean. c. only plants live in intertidal zones because the animals float away with the waves and never return. d. the mechanical forces of the waves can dislodge the organisms from their habitat.

Which of the following is not a symptom of desertification? a) decrease in salt content of the soil b) lowering of the water table c) reduced surface water d) increased soil erosion e) loss of native vegetation

Transmission electron microscope are best for viewing a) microorganisms in pond water b) internal organs of a mouse c)internal structures of a cell d) surface features of a specimen