The correct option is D.
When it comes to movement of particles in an out of cells, there are two basic types of transportation, these are passive and active transportation. The passive transportation of particles does not require the use of energy while the active transport system requires the use of energy in the form of ATP. From the diagram given in the question, it can be seen that energy is involved in the process. Energy is mainly needed to move the particles against the concentration gradient since the inside of the cell is highly concentrated while the outside has low concentration. <span />
The answer is; detecting stars that are behind nebulae that would normally block out other stars
Radio waves have large frequencies unlike the other waves of the electromagnetic spectrum. Due to their large wavelength, they are much larger than the size of an atom hence cannot be blocked or deflected by atomic nuclei. This is unlike gamma rays (and other short wavelength electromagnetic radiation) that are smaller than atoms and easily blocked and deflected by atomic nuclei. Such radiations are extremely attenuated when they pass the through nebula cloud. Radio waves hence overcome this challenge.
The answer is B. The level of classification increases. In 1950 scientists grouped all living things into five kingdoms which include animals, plants, bacteria, fungi and protista. It was untill 1990 that the scientist realized that bacteria and archaea have different distinct characteristics.
Protected from the harmful effects of free radicals, often referred to as reactive oxygen species (ROS).
Hydrogen Peroxide (H2O2) is a by-product of metabolic reactions of cells that use oxygen (aerobic respiration) to produce energy from carbohydrates (food). The problem with H2O2 is that it can be toxic to cells, due to its free radical properties, as an ROS. Organisms protect themselves from this by using an enzyme called peroxidase, also known as cayalase.