Life Forms and Location

I was watching a show during my workout on planets and how scientists were looking for life on the different planets and where they thought it might occur. Throughout the show they kept talking about how life is affected by the different atmospheres and whether that particular planet could support life. And if it was too hot or cold they ruled it out. They then looked at Earth and where all microorganisms were and if and how they survived. They then realized that as long as there is water they can survive in some of the harshest climates.

This got me thinking that some of the organisms that they kept calling life were only seen using a microscope, which meant that they were single cell organisms and very small. This then got me thinking about the other side of the coin and death. Some left organizations say that we shouldn't kill animals since that is cruel and murder. Well if these tiny organisms are considered life and they are purposefully squished is that then considered unnecessary termination of life or murder? If one goes hunting for food, PETA will be upset at them for the unnecessary termination of life, or murder, even if the hunter plans on eating the animal and using the hide for clothing or to sell for the making of clothing. I then took my thinking to the next step. If one was to kill a human, that is made up of many tiny living organisms, than that would be considered murder as one has terminated the life of another. Now if we place one of these organisms inside of a womb and call it a baby then the left will not consider this organism a life form, but a choice. Again outside the womb and it is life, inside the womb and it is not. For if it was considered a life form then the only other conclusion is that the ending of that organism, abortion, is then considered murder. So how can it possibly be argued that killing of a life form outside the womb is murder but as long as that life form is in the womb it is not? Where is the logic in that?