A scientist constructs a graph to show the age structure of the human population of Country Y. The graph is shown here. What conclusion is supported by the graph?
a. The population is decreasing because there are fewer older members than younger members.
b. The population is relatively stable because there are fewer older members than younger members.
c. The population is relatively stable because the death rate is about the same as the birthrate.
d. The population is increasing rapidly because of the youth of the population.

Advances in technology have enabled scientists and researchers to better study the evolutionary relationships between species

What is true of sea slugs in these orders

Juan and carol were studying invertebrates in biology. they knew that segmented or earth worms preferred a dark, moist habitat. during this lab, they would be investigating the responses of organisms called planaria or dugesia tigrina. these were simple flatworms that still had a one-way digestive system and a very simple nervous system. juan and carol placed the planaria in a petri dish containing cool, distilled water that was partially covered with black paper. they shined a light on the dish. next, they removed the paper and placed a small amount of chicken liver at one end of the dish. they added a few large salt crystals to the water. finally, they added drops of hot water to the cool water in the petri dish. their results can be seen in the data table. according to their experiment, all but one conclusion is valid.