which is most likely to inhibit the flow of water through a plant?

a. a decrease in the number of root hairs
b. excess carbon dioxide in the atmosphere
c. damage to the vascular tissue
d. a decrease in the concentration of minerals in the soil

Which kind of worm has a closed circulatory system? a planarian b fluke c pinworm d an earthworm

Which genetic disorders, caused by an extra x chromosome (xxy), is characterized by a lack of testicular development in males, effeminate features, possible mental impairment, and a thin stature?

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.