Average time on market: 41 days Certified Pre-Owned: No Transmission: Automatic Color: Onyx Black Description: Used 2012 GMC Yukon XL 1500 SLT 4WD for sale - $16,900, 118,236 miles with Bluetooth, Leather Seats, Backup Camera, Aluminum Wheels, Navigation System.
How long ago did the first living forms appear on earth? the earliest known life form were single celled organisms which roamed the earth they appeared around two billion years ago Answer: The Earth formed about 4.5 billion years â¦ ago. 700 million years later (3.8 to 3.5 billion years age) life started.5 people found this useful.he earliest known life form were single celled organisms which roamed the earth they appeared around two billion years ago Answer: The Earth formed about 4.5 billion years â¦ ago. 700 million years later (3.8 to 3.5 billion years age) life started. 5 people found this useful.
Quick Answer. The basic unit of life is the cell. In 1838, scientists Theodor Schwann and Matthias Schleiden came up with the original version of the cell theory, which concluded that the basic unit of living things is the cell. Robert Hooke first saw these units in his microscope study of slices of cork and named them cells..