By the eighth week of human fetal development, ____
a. the embryo does not look human yet
b. the neural tube has just begun to differentiate
c. upper and lower limbs have formed, but individual fingers and toes have not begun to differentiate
d. male or female reproductive structures have not started to form yet
e. male or female reproductive structures are forming
ANSWER: e
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A scientist is studying several areas along an elevation gradient. Her study involves prescribed burns (purposefully set, low-intensity fires) in the different areas, followed by a comparison of the type and abundance of organisms that colonize them over the next ten years. What scale best describes her study?
A. Physiological ecology B. Ecosystem ecology C. Organismal ecology D. Community ecology E. Population ecology
What statement best summarizes the nature of scientific inquiry? a. Explanations about nature must be testable in ways that others can repeat
b. Once experimentally verified, scientific hypothesis becomes scientific fact. c. Moral, philosophical, and ethical values will eventually be replaced by rational explanations. d. Personal experience, insight, and revelation are as valid as experimental data.
Glycolysis occurs in which location inside of a cell?
a. mitochondria b. chloroplast c. cytoplasm d. ribosome
Which of the following animals has an eye with a single lens?
A) Dragonfly B) Jellyfish C) Human D) Butterfly E) Bee