Vertebrates such as ____ have both exo- and endoskeletons
a. birds
b. humans
c. turtles
d. lobsters
e. fish
ANSWER: c
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One of the characteristics of chordates is the presence of pharyngeal slits. What was the function of this structure early in chordate history?
A. respiratory surface (gills) B. jaw support C. feeding D. part of the jaw
Which of these green algae are unicellular?
a. Spirogyra b. Volvox c. Chlamydomonas d. Ulva
Births before _____ weeks are considered premature
1.22 2.26 3.37 4.42
In the controlled laboratory experiment with mice and artificial sweetener, one third of the mice receiving sweetener had bladder cancer. Which of the following would be the best conclusion to this experiment?
A. Since two-thirds did not, this proved that there is still no direct cause and effect relationship B. This is a small group (100) and such a result could easily be a random result C. Biological systems are very complicated and results of one third represent an outcome of this complexity;these results give us our best approximation of the likely effects of this sweetener D. Although none in the control group developed cancer, only a small number of cancerous mice would be required to equal the experimental cases, so it is the number control animal that must be increased to be sure it is not a random effect