Why is it thought that homeotic genes arose very early in the evolution of animals?
What will be an ideal response?
Homeotic genes that function in similar ways in evolutionarily distant animals are evidence of shared ancestry. Homeotic genes that exist in many organisms (e.g. humans, squids, mice) can also work in fruit flies. The genes most probably arose before these organisms diverged.
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The major histocompatability (MHC) molecule is important in a T cell's ability to _____
A) distinguish self from nonself B) recognize specific parasitic pathogens C) identify specific bacterial pathogens D) identify specific viruses E) recognize differences among types of cancer
At what point(s) on the graph does the growth of the predator population = 0?
a. at the 2 points where the prey isoclines intersects the ellipse b. at the 2 points where the predator isoclines intersects the ellipse
Which of the following control methods measures the results of mangers' and workers' efforts instead of measuring what they do?
A. Behavior control B. Output control C. bureaucratic control D. Normative control
Of the following conditions, which is absolutely necessary for diffusion to take place?
A) a differentially permeable membrane B) a true solution C) a concentration difference D) a non-permeable membrane E) a living cell