Answer :Four characteristics were to be used for the classification of all viruses:
Nature of the nucleic acid in the virion.
Symmetry of the protein shell.
Presence or absence of a lipid membrane.
Dimensions of the virion and capsid.
Explanation:
The four important characteristics of respiratory surface are:
1. Thin walls
2. Moisture
3. Large surface area
4. Blood supply
Respiratory system or respiratory tract is divided into upper and lower tract. Upper respiratory tract includes nose and its cavities, sinuses, pharynx and the part of the larynx. Lower respiratory tract consists of the trachea, bronchi, bronchioles and the alveoli.
Alveoli are the ends of the respiratory tract the smallest units in it. Alveoli are small folded air sacs that are branching off from alveolar ducts and providing an extremely large surface area for the gas exchange. Gas exchange occurs thanks to small blood vessels – capillaries that surround alveoli and it occurs via the process of diffusion.
So, respiratory surface is thin membrane also known as the blood–air barrier that consists of the alveolar epithelial cells, their basement membranes and the endothelial cells of the alveolar capillaries.
Answer:
B: The virus has a long period of latency
Answer:
What is carbon hydro
<h3><u>A hydrocarbon is a molecule whose structure includes only hydrogen and carbon atoms</u></h3>
Explanation:
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<em>The carbon atoms join together to form the framework of the compound, and the hydrogen atoms attach to them in many different configurations.</em></u></h3><h3><u>
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