Gametes that are the same in size and shape. Having gametes of different size and shape. Usually oogamous organisms have eggs and sperm. The female gonad in animals.
The correct answer is that the yolk provides nutrients for the embryo. Hope this helps.
Answer:
Vaccinations
Explanation:
For example, if a disease has an R0 of 18, a person who has the disease will transmit it to an average of 18 other people. That replication will continue if no one has been vaccinated against the disease or is already immune to it in their community. So if you have (for example) a vaccination then you're less likely to get it, resulting in a lower R0
They have two pairs of main nerve cords organized around a number of paired ganglia. while they don't have a "true brain"-- they have somewhat of a nervous system, composed of the two, or three pairs of nerve cords contained in the visceral mass.
