ACT: Questions

Passage 2

During incubation, a bird embryo, like a mammal embryo, uses oxygen to satisfy its energy needs. However, unlike a mammal embryo, a bird embryo cannot rely on its mother to supply the necessary oxygen. The oxygen must be supplied directly from the outside environment by diffusion through pores in the egg's shell. Diffusion is the movement of substances through a membrane from a region of higher concentration to a region of lower concentration.

Based on this fact, a group of scientists suspected that there might be a relationship between the mass of an egg and its total pore area. A pore is a channel through which substances can diffuse from one side of the membrane to the other.

To investigate this concept, the scientists collected the data shown in the table in Table 1.

Question: Assuming a species of bird has an average egg mass of 500 g, what would be the predicted pore area of its eggs?

Choices:


	A.		${1.5 mm}^{2}$
	B.		${40 mm}^{2}$
	C.		${750 mm}^{2}$
	D.		${greater than 750 mm}^{2}$

The correct answer is B.

Choice (B) is correct. 500 g would place this egg between the goose (250g and 15 mm²) and the emu (800g and 55 mm²). The only choice between 15 mm² and 55 mm² is (B), 40 mm², so (B) is correct.

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ACT: Questions

ACT: Science Question #6