According to piaget, at what age will most children enter the concrete operations stage of cognitive development?

a. between the ages of 4 and 6

b. usually by age 2

c. by age 12

d. by age 7

How would you account for the fact that fossils of fish are not present in the older layers of rock?

What is one way phytoplankton contribute positively to the ecosystem?

Mario performed an experiment to determine if photosynthesis was affected by the amount of light that a plant received. The data from his experiment are shown in the table below. What could he have done to increase the validity of his data?

Which organelle (s) would be active in liver cells that are detoxifying alcohol?

Referring to the graph, what phase would account for approximately half of the time spent from a cell in the cell cycle?

What are the three major organs of the nervous system

What is the genotype of the offspring missing on the first row of the punnett square? A.) lBlB B.) lAlB C.) lBlO D.) none of the above

Cells throughout an organism can develop in different ways to perform blank.

What is the main function of a fungus's hyphae

The smaller vessels that carry blood away from the heart and connect the arteries to the capillaries are called the: