Answer:
alveoli
Explanation:
They are the smallest structures in our lungs where capillaries exchange O2 and CO2 in blood.
Answer:
A. Constipation
Explanation:
As there would be easy passage of faeces, based on an increase in roughage for the colon to press and rub against
Answer:
to get, acquire or secure
Answer:
you should always wash your hands regularly and avoidance of shaking hands
Answer:
<h3>Viruses can only replicate themselves by infecting a host cell and therefore cannot reproduce on their own.</h3>
<h3>At the most basic level, viruses consist of genetic material contained within a protective protein coat called a capsid; the existence of both genetic material and protein distinguishes them from other virus-like particles such as prions and viroids.</h3>
<h3>They infect a wide variety of organisms: both eukaryotes (animals, fungi and plants) and prokaryotes (bacteria).</h3>
<h3>A virus that infects bacteria is known as a bacteriophage, often shortened to phage.</h3>
<h3>The study of viruses is known as virology, and those who study viruses are known as virologists.</h3><h3 /><h3>It has been argued extensively whether viruses are living organisms.</h3>
<h3>Most virologists consider them non-living, as they do not meet all the criteria of the generally accepted definition of life.</h3>
<h3>They are similar to obligate intracellular parasites as they lack the means for self-reproduction outside a host cell, but unlike parasites, viruses are generally not considered to be true living organisms.</h3>
<h3>A primary reason is that viruses do not possess a cell membrane or metabolise on their own - characteristics of all living organisms.</h3>
<h3>Examples of common human diseases caused by viruses include the common cold, the flu, chickenpox and cold sores.</h3>
