Problem 6 - Biology: The Dynamic Science

Question

The difference between the vertebrate eye and the cephalopod eye is that the vertebrate eye has: a. an iris surrounding the pupil, whereas in cephalopods the pupil surrounds the iris. b. a lens that changes shape when focusing, whereas in cephalopods the lens moves back and forth to focus. c. a retina that moves in the socket when recording the image, whereas in cephalopods the retina changes shape when stimulated. d. a pupil that shrinks in size in bright light, whereas cephalopods have a pupil that enlarges in bright light. e. retinal synthesized from vitamin A, whereas cephalopods lack retinal.

Step-by-Step Solution

Answer

The correct answer is option b: a lens that changes shape when focusing in vertebrates, whereas in cephalopods the lens moves back and forth to focus

Step 1: Rule out incorrect options

Option a is incorrect because both vertebrate and cephalopod eyes have an iris surrounding the pupil. Option c is not correct because the retina does not physically move to record images in either type of creature. Option d is also wrong because the pupil in both types of organisms shrinks in bright light to protect the retina. Finally, option e is not true as both have retinal synthesized from vitamin A.

Step 2: Identify the correct answer

This leaves option b as the only remaining option, and it is indeed correct. The primary difference between the vertebrate and cephalopod eyes in terms of focusing is that vertebrates change the shape of their lens to focus (accommodation), whereas cephalopods move the lens back and forth in order to focus on objects at different distances.