Which of the following occurs during gastrulation?
a. formation of the gray crescent region
b. formation of ectoderm, mesoderm, and endoderm
c. closure of the archenteron
d. formation of the blastocoel
e. radial cleavage takes place
b
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After a forceful exhalation of the maximum volume possible, what volume of air must be inhaled to resume normal breathing?
a. vital capacity b. functional residual capacity c. tidal volume + expiratory reserve volume d. inspiratory reserve volume + tidal volume
Why are endemic species inherently so vulnerable?
A. they may provide new discoveries in medicine B. they occur in a particular region of the world and nowhere else on earth C. they are part of the coral reef ecosystem on the brink of extinction D. they are able to evolve when their environment is threatened E. All of the above are correct.
The sporophyte generation
A. is diploid. B. is haploid. C. is not found in ferns. D. produces sex cells.
How does the plasma membrane of bacteria and archaea differ?
A) Archaea build only lipid monolayers. B) Bacteria have phospholipids built from branched fatty acids. C) Archaea have phospholipids built from branched fatty acids. D) Bacteria build only lipid monolayers. E) Archaea have phospholipids built from linear fatty acids.