Gas exchange of oxygen and carbon dioxide takes place in the alveoli<span>. Oxygen from the inhaled air diffuses through the walls of the </span>alveoli<span> and adjacent capillaries into the red blood cells. The oxygen is then carried by the blood to the body tissues.</span>
Answer:
decrease, decrease
Explanation:
By using antimalarial drugs in order to prevent malaria, the frequency of the sickle cell allele decreases in both areas where malaria is endemic and the areas where no incidence of malaria occurs because there is no necessity of sickle cell allele in the population to prevent malarial disease. Sickle cells have high significance in prevention of malarial diseases so when there is no malaria happens in the population so there is no need for it and the allele slowly removed from the population and decrease occurs in its frequency.
Because Americans like Junk food :)
Answer:
shells 1, 2 and 3 are full and shell 4 has one electron
Explanation:
The distribution fo the electrons possessed by an atom in the shells surrounding it is termed as its electronic configuration.
According to the rules of writing the electronic configuration:
1. The first shell can be occupied by a maximum of two electrons.
2. the subsequent shells can be occupied by a maximum of 8 electrons.
3. the subsequent shells are filled only once the lower shells have been filled.
Based on these rules, the electronic configuration of potassium should be 2, 8, 8, 1. (2+8+8+1 = 19).
Thus, we can see that the first three shells are filled, and the last one has one electron left.
