Look at the age-structure pyramids. the numbers between the bars (in the middle of the graphs) serve as the y-axis. what do these numbers represent? a) the population of males and femalesb) the age classes, in 5-year rangesc) the total population, in millionsd) the number of people born in a particular yeare) the percentage of the population in each age class

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Which statement about the pancreas is not true? a. it is an endocrine organ in the abdomen. b. it release chemicals into the digestive system. c. it releases insulin to increase glucose levels. d. it release hormones into the bloodstream.

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.