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:
1. Queen bees lay their eggs after within each cell inside a honeycomb.
2. True. Worker bees feed the larvae with a combination of nutrients, from nectar and pollen to bee milk and water.
Explanation:
1. Queen bees lay their eggs after within each cell inside a honeycomb (hive) <em>[</em><u><em>See image below]</em></u><em> </em>during the winter.
The queen is able to lay over two thousand eggs PER DAY! Each egg has an approximate size of 1 mm long. This process then leads to the formation of a whole new colony of bees.
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2. True.
Worker bees have the largest density of all, that is, there are numerous worker bees within a colony. As their name "worker" implies, they have plenty of tasks to perform. For example, they have to clean the hive regularly, ventilate it during warm conditions or keep it warm during cold conditions, and also care for the queen. However, one the most important roles of workers is to feed the larvae, during this stage they are also called "nurse bees." These bees feed the young with a combination of nutrients, from <u>nectar and pollen to bee milk and water</u>.
Answer:absorption and secretion
Explanation:
The main function of epithelial cells with large amount of cytoplasm is absorption and secretion. They're usually present sweat and oil glands of the skin due to its secretive function.