Population is the term that is used to describe a group of arctic foxes that live in part of Alaska's Arctic National Wildlife Refuge. The correct option among all the options given in the question is the third or the second last option. The area covered by Arctic National Refuge is approximately 19.6 million acres. It has a variety of wild animals living in it.
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Answer: The immune system
Explanation:
The immune system is a complex network of proteins and cells that defends the body against infection or any invasion. The human defense system in the body is actually made up of entire organs and vessel systems like the lymph vessels. The immune system is made up of organs that control the production and maturation of certain defense cells.
Initially, all living things are subjected to attack from disease causing agents. Even bacteria, so small that more than a million could fit on the head of a pin, have systems to defend against infection by viruses. This kind of protection gets more sophisticated as organisms become more complex.
Answer:
70 ml/beat.
Explanation:
Stroke volume may be defined as the volume of the blood that are pumped by the left ventricle in one contraction. The blood output can also be determined by knowing the stroke volume.
The stroke volume can be calculated by the formula as follows:
Stroke volume = End diastolic volume - End systolic volume
Here, end diastolic volume = 120 and end systolic volume = 50.
Stroke volume = 120 - 50
Stroke volume = 70 ml/ beat.
Thus, the answer is 70 ml/ beat.
