The answer is atrial depolarization. The P wave of a normal electrocardiogram specifies atrial depolarization. In addition, depolarization happens in the four compartments of the heart which is both atria first and in both ventricles. The sinoatrial or as called as SA node on the wall of the right atrium starts depolarization in the right and left atria that can cause the contraction in which it is symbolized by the P wave on an electrocardiogram.
First law is Law of Conservation of Energy it states that enegy cant be made in a isolated system. The second law is Law of Thermodynamics it states that the entropy of any isolated system always increases.
Answer:
Cilia, tail-like projections found on the surface of cells, are perhaps best known as molecular flippers that help cells move around. ... Cilia, tail-like projections found on the surface of cells, are perhaps best known as molecular flippers that help cells move around.
Explanation:
1.The Moon has phases because it orbits Earth, which causes the portion we see illuminated to change. The Moon takes 27.3 days to orbit Earth, but the lunar phase cycle (from new Moon to new Moon) is 29.5 days. The Moon spends the extra 2.2 days "catching up" because Earth travels about 45 million miles around the Sun during the time the Moon completes one orbit around Earth.
2.
An eclipse is the result of the total or partial masking of a celestial body by another along an observer's line of sight. Solar eclipses result from the Moon blocking the Sun relative to the Earth; thus Earth, Moon and Sun all lie on a line. Lunar eclipses work the same way in a different order: Moon, Earth and Sun all on a line. In this case the Earth's shadow hides the Moon from view.Lunar and solar eclipses occur with about equal frequency. Lunar eclipses are more widely visible because Earth casts a much larger shadow on the Moon during a lunar eclipse than the Moon casts on Earth during a solar eclipse. As a result, you are more likely to see a lunar eclipse than a solar eclipse.
3.Why Do We have Seasons?
As the earth spins on its axis, producing night and day, it also moves about the sun in an elliptical (elongated circle) orbit that requires about 365 1/4 days to complete. The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons. When the earth's axis points towards the sun, it is summer for that hemisphere. When the earth's axis points away, winter can be expected. Since the tilt of the axis is 23 1/2 degrees, the North Pole never points directly at the Sun, but on the summer solstice it points as close as it can, and on the winter solstice as far as it can.
Why Do the Seasons Change on Earth?
Two things cause the seasons to change. First, the Earth moves around the Sun. Second, the Earth has a tilted axis of rotation.
The Earth spins around an axis. This imaginary line extends from the South Pole to the North Pole. But the Earth’s axis is not vertical. It’s actually tilted at an angle of 23.5°. The planet is always tilted in the same direction as it orbits the Sun.
Answer:
True!
Explanation:
The development of soils can be significantly affected by vegetation, animal inhabitants, and human populations. Hope this helps!
