The best answer is b. 4
The human heart has four chambers - two atria and two ventricles.
1. Right atrium - receives oxygen-poor blood from the body and pumps it to the right ventricle.
2. Right ventricle - pumps oxygen-poor blood to the heart.
3. Left atrium - receive oxygen - rich blood from the lungs.
4. Left ventricle - pumps oxygen rich blood to the body.
The heart is a muscular organ. It is about the size of a closed fist. It is located in the thoracic cavity. It is protected by the rib cage and is the major organ of the circulatory system.
The part of the fibula that is found near the Knee joint is the head
A vector is a quantity with magnitude and_____
direction! :)
Answer:
Mutations leading to the better attachement of virus to the host cell would allow the virus to spread the infection and leave more progeny. The reproductive fitness of mutant viruses would allow the mutation to spread.
Explanation:
1. The organisms with same resource requirement compete with each other. Viruses are not living things but once inside the host cell, they behave like living things. Rapid multiplication of virus overpopulate the host cells.
2. Genetic variations are added to the viral progeny by random errors during replication of the viral genome. These random variations may impart beneficial trait, harmful feature or remain neutral. If a random mutation in the SARS-CoV2 virus allows it to adhere better to the cells of the respiratory system, the virus would be better able to infect these cells to spread the infection. Once inside the host cells, the mutant virus would leave more progeny. On the other hand, the wild type virus that lack this mutation would have lesser chances of entering the host cells and may or may not replicate.
3. The progeny of the mutant virus would compete better with the non mutant ones due to the presence of same mutation.
4. Differential reproduction and more progeny of the mutant virus would spread the mutation among the virus.
