What are some of the reasons why placental mammals appear to have outcompeted monotremes and marsupials, the other two groups of mammals?
What will be an ideal response?
Placental mammals develop the young internally far longer than the marsupials, and don't lay eggs like the monotremes. A placenta delivers nutrients to the fetus directly, so it can be born at a more advanced stage. Many placental mammals have young that can walk virtually within minutes after birth. Internal incubation helps keep young warm longer and protects them from predators at a very vulnerable stage.
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Which of the following is true of a lysosome?
A) The lysosome may mature from a late endosome. B) The lysosome may function in glycosylation. C) The contents of the lysosome originate in the smooth ER. D) The lysosome functions in export packaging. E) all of the above
The digestion of proteins begins in the ____
a. stomach b. pancreas c. small intestine d. large intestine e. esophagus
__________ secrete products such as sweat or digestive enzymes through ducts. Fill in the blank(s) with the appropriate word(s)
One characteristic that makes Caenorhabditis elegans attractive for developmental studies is:
a. its small, transparent body. b. the extensive number of genes shared with humans. c. the developmental defects that occur in this organism. d. the close evolutionary relationship between this mammal and humans. e. the presence of zygotic segmentation genes, similar to those found in humans.