Answer:
This means that the two separate rocks were once part of one piece of rock. These layers got separated most probably by continental drift as a result of tectonic plate movements. An example of such a fossil is the Mesosaurus, a freshwater crocodile-like reptile, that is found in Southern Africa and Eastern South America continents- that means they were once one land mass.
The environment in these two separate layers would most likely be different. As the layers drift apart from each other , they drift across latitudes that are determinants of climate in a region. Therefore, even the organisms in these two rock layers will evolve differently (even though they will share a common ancestor) in adaptation to respective environments – this is called allopatric speciation.
Answer:
cytosol (intracellular fluid), interstitial fluid, plasma
Answer:
Explanation:
Immunity to a disease is achieved through the presence of antibodies to that disease in a person's system. Antibodies are proteins produced by the body to neutralize or destroy toxins or disease-carrying organisms. Antibodies are disease-specific. Viruses make us sick by killing cells or disrupting cell function. Our bodies often respond with fever (heat inactivates many viruses), the secretion of a chemical called interferon (which blocks viruses from reproducing), or by marshaling the immune system's antibodies and other cells to target the invader. A vaccine works by training the immune system to recognize and combat pathogens, either viruses or bacteria. To do this, certain molecules from the pathogen must be introduced into the body to trigger an immune response.
These molecules are called antigens, and they are present on all viruses and bacteria.
