Still finishing the Science summer packet. Just need a little more help people. I need to know:
What are the three groups mammals are classified in?
How are the three groups of mammals classified?
To answers question number two you'd have to start off by something like, "In the first group mammals are classified by their..."
I ask again that I please get the answer insteadof just links. Thanks much ^_^
2007-08-25 09:29:42 · 2 answers · asked by The Girl With All the Answers 2 in Science & Mathematics ➔ Zoology
O thanks so much Vincent. And I appreciate the word Coyote. It's obvious to me what I should be doing thank you very much for your concerrn though.
2007-08-25 12:24:45 · update #1
How about... "In the first group of mammals we have a kid who does not want to take the time to do their homework."
DO YOUR OWN WORK!
2007-08-25 11:12:43 · answer #1 · answered by The Cheshire 7 · 1⤊ 1⤋
Monotremes
Marsupials
Placentals
The classification is based on how the babies develop. In the case of the monotremes, the babies hatch form an egg (yes, like birds!) They are still mammals because the mother produces milk to feed the young. There are only two monotreme species: the spiny anteater, and the platypus.
Marsupials give birth to embryos (kangaroos even lack hind legs when they emerge) and those travel to the marsupial pouch when the attache themselves to a teat to complete their developement. Most known marsupials live in Australia (kangarouus, tasmanian devel, koala, etc) although the opossum (also a marsupial) is spread out outside of Australia.
Placental mammals give birth to developped babies, which relied to a planceta--an organ that intefaces with the mother's circulatory system--to support the development of the embryo.
Placental mammals are everything else that is not monotreme or marsupian. Cats, dogs, cows, dophins, elephants, mouse, rabbits, seals, monkeys, humans, bears, etc. are all placental mammals.
2007-08-25 16:50:41 · answer #2 · answered by Vincent G 7 · 2⤊ 0⤋