What are white blood cells protect against pathogens and aid in blood clotting when injuries are sustained.
Answer:
Scientists mostly gain new knowledge through direct observation and applying the scientific method. They would start with a hypothesis and test it, then change it or confirm it. Others would test their confirmation from one point, while the third group would test what the second said. And so on and so forth.
Explanation:
The correct answer should be the Periderm.
It is not as simple as this, of course and you would be wise to know that periderm is just a part of the overall concept that is bark, because bark is not a biological term.
Edwin Hubble used the Doppler effect to determine that the universe is expanding. After years of scientific research and observation of different celestial bodies through a telescope, Hubble found that the light from distant galaxies was shifted towards the red end of the spectrum. This red shift indicates that stars are moving away from us and from each other. This phenomenon is called the 'expansion of the universe', also known as the big band theory.
