Flu vaccines need to be revised and changed every year because the flu virus constantly mutates. Flu viruses can change in two ways: drift or shift. Antigenic drift occurs when genes of the virus slowly change during replication until the immune system no longer recognizes it. On the other hand, antigenic shift occurs when a major change in the virus happens. This usually leads to a totally different kind of virus. This is what happened during the H1N1 scare in 2009.
DNA viruses like mumps are less prone to mutation due to the presence of DNA polymerase. RNA viruses are more prone to mutation because they undergo reverse transcription to simulate the role of DNA.
Answer:
The rate of reaction depends on the rate determining step of a nonelementary reaction
Explanation:
A non elementary reaction is a reaction that proceeds in a sequence of steps. One of the steps is usually the slowest step in the reaction sequence. This slowest step is called the rate determining step. In an SN1 reaction, the rate determining step is the formation of the carbocation, the concentration of the carbocation affects the rate of reaction because it is involved in the rate determining step. The attack of the nucleophile is a fast step and does not affect the rate of reaction.
Answer:
many system and many functions of body systems.
Like- nose ,and functions is they were smell in any things.
second - ear, functions is they were any sound to feel together.
third-tongue , functions is they were any taste feel in what can I do in salt and bitter.
AND MANY OTHER FUNCTIONS TOGETHER.
I HOPE LIKE THIS ANSWER
Break the deg on thing off.
Let us assign the
recessive allele for freckle to be f and
the dominant F. According to the statement, we deduce that ff = 0.04.
The frequency of the recessive f allele is, therefore, is
0.2 (square root of 0.04 ).
Hardy-Weinburg p + q = 1
P + 0.2 = 1; p = 1- 0.2 = 0.8
Therefore using the Hardy-Weinburg equation of a population
in equilibrium
P2+2pq+q2=1
Heterozygous individuals are;
2pq = 2*0.8*0.2 = 0.32
This is 32% of the population
