Answer: Gray whales are the common ancestor of the Blue and Humpback whales.
Ancestors of Blue whale include: Gray?
The three observations that could help an individual in distinguising whether the organism is a fish or not is that it should live under water as fish can't survive without water, another thing is that it should laid eggs when it comes to giving birth because when it does not lay eggs but produces a living organism normally without an egg, it is considered to be a mammal and lastly, the appearance it possess such as having gils or fins.
An intramuscular injection is a technique delivering a medication that is deep into the muscles. If intramuscular is administered too high then the efficacy of the vaccine might be reduced as it is not injected in the right site. It might also cause to injure blood vessels so it should be injected in the correct site and depth.