Answer:
Immune
Explanation:
The immune system helps to protect our body from all sort of organisms ranging from invading toxins and micro-organisms which negatively affects an individual’s health and well being.
Stress has an adverse effect on the immune system such that it weakens and suppresses the functions of the required antibodies in the body system. This is the reason why many aged people fall sick because they have gone through more stress when compared to younger people.
D an animal or plant getting a new "ability" is an example of evolution like this plant can climb now
There are two types of respiration namely aerobic and anaerobic respiration. Anaerobic respiration requires oxygen while anaerobic respiration does not require oxygen. The products of anaerobic respiration (also referred to as fermentation) in yeast are carbon iv oxide and ethanol. Anaerobic respiration has a range of applications in the society which includes Brewing process (bear making process) in alcohol industry, bread making process( baking) in baking industry.
Answer:
Paleontologists didn't have the technology in that time to get a good estimation on the events. Back then, they had to rely on natural sources "markers" that made the estimations. Those estimations weren't accurate. Today's measures are accurate.
The answer is genetic variation because crossing over leads to changing the traits inherited by the daughter cells
