Answer:
d. sampling unit
Explanation:
<u>Sampling unit:</u>
Refers to the unit or group of elements that are selected from an original population during an investigation. The sampling unit might be composed of a statistical unit or a group of statistical units.
The statistical unit or element is the elemental unit that composes the target population.
The sampling unit is a basic concept to keep present during the development of the investigation project. It is the minimal unit of observation that will be used to take information about the variables of interest. All the sample unit composes the population and is defined by an <em>N</em>, while only some representative sample units compose the sample, and are represented with an <em>n</em>.
So, the whole population can not be measured because of its size, or the individuals´ characteristics, among other many factors. So we need to take a random and representative sample or group of the population to proceed with our investigation. This sample or group is composed of some of the original population individuals, which are defined as "sample units".
Blood<span> flows to the </span>kidneys through<span> the right and left renal arteries. Inside each </span>kidney<span> these branch into smaller arterioles. The </span>blood<span> is at very high pressure and flows </span>through the arterioles into tiny knot of vessels called the <span>Glomerulus.
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Viruses enter human body like an invader and uses the living cells to replicate causing infections in the cell or can damage it.
Explanation:
The attacks of viruses on the body of living organisms is compared with a ‘sneak attack’ as they invade the body and enters into a living cell to replicate themselves. This may cause damage or bring about changes in the cell causing sickness and infections.
They can hide themselves on our body attacking sneakily to harm the immune system to fight the infection. This stealth infection can result in fever, damaging immunity, disorder etc.