When a primary tumor spread it called methastastasis
In the lytic cycle, a virus that has invaded and entered a cell takes over the cell's replication mechanism. The virus makes viral DNA and viral proteins.
The virus then lyses (breaks open) the cell membrane, allowing the newly produced viruses to leave the now disintergrated host cell to infect other new cells.
The lytic cycle is considered the main method of viral replication. It is even more common than the lysogenic cycle. It has helped scientists understand better how the immune system responds to pathogens.
Species evolve independently possibly due to geographical isolations or behavioural isolations.
Geographical isolation includes the isolation of 2 groups of the same species. Since these 2 groups live in different locations, (e.g. a volcanic eruption resulting in a barrier between one side of an ocean and another side of the ocean), they will have different selection pressures in their different environments as well (e.g. one side of the ocean may have more sunlight and thus more underwater plantations than the other side of the ocean). Natural selection will eliminate those with disadvantageous characteristics (e.g. Fishes that only eat plants and nothing else on the side of the ocean with little plantations) with unfavourable alleles, and select for those with advantageous characteristics (e.g. Fishes are able to eat plants and other organic substances as well on the side of the ocean with little plantations) with favourable alleles.
Since the 2 groups have different selection pressures, natural selection will occur in different ways, selecting for and against different types of fishes with different types of alleles. Also, because of the barrier, they are not able to mate with each other, and there are no mixing of genes from one side of the ocean and the other side. They are genetically isolated. As genetic drift occurs over time, their gene pools become different from each other. Thus, they evolve independently.
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The answer is A. i had this question yesterday
Answer: they allow air to enter lungs and also permits air into the body
Explanation: