Answer: What makes a marsupial, a marsupial? A discussion on the historical biogeography and biological evolution of marsupial mammals. Dr. Robert Voss is a professor at Richard Gilder Graduate School and the American Museum of Natural History. His primary research interests are the evolution of marsupials and the systematics and biogeography of other Neotropical mammals that inhabit moist-forest habitats in Amazonia and the Andes.
What anatomical characteristics distinguish marsupial mammals from placental?
Living marsupials and placentals can be distinguished by a number of anatomical features, including structural differences in their ear regions, teeth, postcranial skeletons, reproductive tracts, and brains. Most people think of pouches when they think about marsupials, but not all marsupials have pouches.
When did these two subclasses of mammals separate from their common ancestor? What do we know about that common ancestor?
The lineages that gave rise to living marsupials and placentals are recognizably distinct in the fossil record as far back as the Early Cretaceous (about 125 million years ago), so the most recent common ancestor of these groups must have lived even earlier. How much earlier is controversial, with some estimates suggesting a date of almost 150 million years (in the Late Jurassic). We don’t know anything about that ancestor for certain, but we assume that it was not unlike the earliest known marsupials and placentals: probably a small climbing (arboreal or semiarboreal) mammal, perhaps superficially resembling living opossums or tree shrews. Because the earliest known marsupial and placental fossils are from China, most paleontologists assume that their most recent common ancestor lived somewhere in eastern Asia.
What is convergent evolution and what are some examples of convergent evolution between marsupial and placental mammals?
Convergent evolution is the appearance of similar traits in distantly related lineages. Examples of convergent evolution between placentals and marsupials are the extinct Tasmanian “wolf” (a very wolflike marsupial), marsupial “moles” (living molelike marsupials that burrow in the sandy deserts of Australia), and kangaroo rats (North American rodents that hop on their hind legs like kangaroos).
Explanation:
The Answer is: C
Because of the volume that is already set by the size and weight of the container. In other words the gas is pushing all particles out of the way and replacing its self therefore the pressure increases.
- Jean Baptiste Lamark
- Thomas Malthus
- Alfred Wallace
- Charles Lyell
Plant cells are specialized for life in a hypotonic environment.
Answer: Option A
<u>Explanation:</u>
A cell which lacks the cell wall, will expand and burst. At the point when set in a hypertonic solution, a cell without a cell wall will lose water to the surrounding, wilt and presumably die.
In a hypertonic arrangement, a cell with a cell divider will lose water as well. The plasma layer pulls from the cell wall as it withers, a procedure called plasmolysis. Thus it can be inferred that plant cell are specialized for life in a hypotonic environment.
<h3><u>Answer;</u></h3>
Waste
<u>Waste</u> is any unwanted substance or toxin that is expelled from organisms. Example: urea, carbon dioxide.
<h3><u>Explanation;</u></h3>
- <em><u>The body must remove waste products from the all the tissues in the body. These waste products are constantly being produced by the body tissues and must therefore be excreted, because if they are not, they will increase in concentration and may interfere with chemical reactions or damage cells.</u></em>
- <em><u>Waste products include, carbon dioxide and Urea</u></em>. They are excreted through various body system and excretory organs, which includes, kidney that eliminates water, urea and other waste products in the form of urine, lungs which eliminates carbon dioxide from the body, and skin which excretes excess water.
