Hello Wtfiswrongwitmeh, using radiocarbon dating, or carbon dating, you can determine the age
of an organic object from the relative proportions of the carbon
isotopes it contains. Therefore, if you take the fossils form the fossil
record and determine how old they are, you can see how/if they evolved
over time.
Answer:
Approximately 4.5 billion years ago (The Hadean Eon) .
Explanation:
The Geologic Timescale's "Hadean" era, named for Hades (Hell, well, we weren't feeling very imaginative that day), encompasses the Earth's origins. According to the evidence we currently have, the Earth's surface at that time was mostly made up of lava lakes and molten rock.
How would that appear? The first 500 Ma of Earth's history have left very little stuff behind. You may, however, take a peek at our moon, which similarly went through a lava lake period before freezing. You'll see that it has both dark and bright landscape.
The lighter material is known as highlands and is primarily composed of anorthosite. Anorthose, a kind of plagioclase feldspar, is the main component of the igneous rock known as anorthosite. According to what we know, the Moon too had a lava lake era. Liquid rocks exposed at the surface were cooling and fractionally crystallizing throughout this lengthy period. A certain order of minerals was developing. And these minerals were dividing up according to the density of the melt; less dense minerals, like plagioclase (Anorthose is a plagioclase), floated to the surface in a sort of incandescent crystal slush slurry and formed a sort of lid there. Denser minerals, like olivines, were sinking to the bottom of the lava lake to form cumulates. As the lava lakes cooled, anorthosite piled on top in successive layers, thickening the mass of floating crystals. Large meteor impacts occasionally pierced this anorthosite crust, and part of the thicker (and darker) underlying liquid accumulated in the ensuing craters to produce those roundish dark patches (Maria), which are now filled with basalt.
After the lava lakes froze/crystallized over, such characteristics were maintained since there was no significant tectonic activity on the Moon (except for the local meteor impacts which screw things up a bit).
Answer:
The correct answer would be Atria push blood into the ventricles and Ventricles push blood out of the heart.
In humans, four chambered heart is present with two atria and two ventricles.
Deoxygenated blood from all over the body is passed into the right atrium through vena cava (superior and inferior).
Simultaneously, oxygenated blood from the lungs is passed into the left atrium of the heart with the help of pulmonary vein.
Both the atria contract at the same time to drain their blood into respective ventricles.
The ventricles undergo relaxation while receiving blood.
The valves present between the atria and ventricles (tricuspid and bicuspid valve) ensures that the blood flows in one way direction only. They shut down as the ventricles contract and produce the sound "lub".
The ventricles contract simultaneously to pump blood out of the heart. The right ventricle pumps deoxygenated blood into pulmonary artery which takes the blood to the lungs for oxygenation.
The left ventricle passes the oxygenated blood through aorta to all the parts of the body.
The pulmonary and aortic valves prevent the back flow of blood and shut at the same time which creates second sound called as "dub".
Answer:
The correct answer is - carboxyl group.
Explanation:
Lipids are one of the major macromolecules that are made up of fatty acid and carboxyl groups as two main parts of the molecules. The most common type of lipid is formed with the glycerol associated with the fatty acid chain.
In the provided structure the circled part is the carboxyl group with the long fatty acid chain. However, glycerol belongs to the alcohol group.
Thus, the correct answer is - carboxyl group.
