The first active Drosophila segmentation genes are the ____, which begin organization of the body into regions
a. pair-rule genes
b. segment polarity genes
c. gap genes
d. homeotic genes
e. maternal effect genes
c
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A type of transport of a solute across a membrane, up its concentration gradient, using protein carriers driven by the expenditure of chemical energy is known as
A. osmosis. B. diffusion. C. facilitated transport. D. active transport. E. exocytosis.
Oxytocin is secreted by the posterior pituitary in females only
Indicate whether the statement is true or false.
The 2-m height attainable by Polytrichum moss is at the upper end of the size range reached by mosses. What accounts for the relative tallness of Polytrichum?
A) the cuticle that is found along the ridges of ?leaves? B) ?leaves? that are more than one-cell-layer thick C) high humidity of surrounding air provides support against gravity D) reduced size, mass, and persistence of the sporophytes allows gametophores to grow taller E) the presence of conducting tissues in ?stem?
Watching salt crystals form as ocean water evaporates, a student says, "Look—more and more crystals are appearing. The ocean water is alive!" Which statement is an accurate evaluation of the student's remark?
A) The student is correct: Crystals are ordered structures and they are reproducing, so the ocean water is alive. B) The student is correct because crystals are formed by processing energy from the sun to create new structures, so ocean water is alive. C) The student is incorrect because the solution is processing energy from the sun rather than gaining energy from other organisms, so the ocean water is not alive. D) The student is incorrect because all of the crystals reproduce the same kind of crystals with no variation to provide adaptation, so the ocean water is not alive.