The ectoderm, one of the three layers of the embryonic disk formed during the germinal stage, of an embryo will later become:
A. the outer layer of skin, the nails, hair, teeth, sensory organs, and the nervous system.
B. the muscles and skeleton.
C. the excretory and circulatory systems.
D. the inner layer of skin, digestive system, liver, salivary glands, and respiratory system.
Answer: A
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An observation that involves identifying specific behaviors that are observable and measurable is called a(n)
a. informal observation b. formal observation. c. unstructured observation. d. self-observation.
When does sampling error occur?
a. When a sample statistic is not equal to the population parameter as a result of nonchance factors b. When a sample statistic is not equal to the population parameter as a result of chance factors c. When there has been an error in calculating the standard error of the mean d. When there has been an error in calculating the sample mean
Characterized by periodic sleep during the daytime, ________ is a sleep disorder that is quite often combined with ________, a complete loss of muscle control that causes sufferers to fall down suddenly
a. insomnia; sleep apnea b. sleep apnea; narcolepsy c. cataplexy; narcolepsy d. narcolepsy; cataplexy
Dr. Ngai just turned 40. To celebrate the beginning of his tenure in middle-age he went to the optometrist and had his vision checked. To Dr. Ngai's surprise the optometrist informed him he suffers from presbyopia, which is __________
a) a loss of elasticity in the cornea that reduces the ability to see far away. b) a loss of elasticity in the lens that reduces the ability to see close up. c) a loss of elasticity in the iris that reduces the ability of the pupil to dilate and contract. d) a clouding of the lens that can lead to blindness.