The three germ layers are established:
A. once the blastula forms.
B. once the inner cell mass of the blastula
forms.
C. once the blastula implants into the uterine
wall.
D. once the cells of the inner cell mass
reorganize themselves into the gastrula.
E. once the gastrula implants into the uterine
wall.
D
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Increasing global population, overcrowding and international travel have contributed to many changes in epidemiological trends of infectious disease. Which of the following would have been just as likely to occur a century ago as today?
A. The incidence of bubonic plague in humans, transmitted via the rat flea, is gradually increasing in the United States with most of the cases reported in the west. B. Gonorrhea, one of the oldest known STDs, is becoming increasingly difficult to treat due to multi-drug resistance strains of Neisseria gonorrhea. C. An individual was placed under a government-ordered isolation after traveling while infected with a drug resistant strain of Mycobacterium tuberculosis. D. West Nile encephalitis, a zoonotic disease caused by a virus first isolated in Uganda, is now a world-wide pandemic in human and animals.
Females always inherit sex-linked traits from their mothers
Indicate whether the statement is true or false
In the cell, energy released by electrons is often used to phosphorylate
A. ADP. B. pyruvic acid. C. oxygen. D. ATP. E. NAD.
The choanocytes have a flagellum that moves water through the sponge and a collar that extracts food particles from the water. In what group have you encountered very similar cells before?
A. the choanoflagellates. B. the chytrids. C. the Euglenozoa. D. the Foraminifera. E. the charophytes.