Ammonite is a species of shellfish that is used as an index fossil. It has a distinct spiral shell. Which statement most likely explains why other
species of shellfish that existed around the same period of time are not considered Index fossils?
A.
Other shellfish did not contain the carbon-14 Isotope.
B.
Other shellfish were much smaller in size than ammonites.
C. Other shellfish were not as widespread as ammonites.
D. Other shellfish did not have a rigid external body, like ammonites.

What is true of all organisms in the kingdoms protista, plantae, fungi, and animalia? a. they are multi-celled. b. they are photosynthetic. c. they have cells that contain membrane-bound organelles. d. they contain cells that lack membrane-bound organelles.

Match each term to its best definition? sedimentary depositional enviornment

Aresearcher designed an investigation to test what effect eating different types of food would have on blood insulin levels. she selected 10 male subjects who were all 25 years of age and in good health. the experiment took place over 3 days. at 8: 00 a. m. on each day, the subjects ate a meal consisting of only 1 type of food. they had their blood insulin levels measured after consuming the meal. on day 1 they ate a high fat diet, on day 2 they ate a high protein diet, and on day 3 they ate a high sugar diel what is the independent variable in this experiment? a the age of the subjects b the blood insulin level c the type of food consumed d the time of day the meal was consumed