You have asked a very interesting question, and I am guessing that you have been thinking about this question a little bit.

When we look at a textbook, and it is titled "Life Science" or we see that term, I think we immediately assume that we will study living things - plants, animals, fungi, bacteria, ecosystems, etc... And that is correct for the most part. But, if we think about it a little further, "Life Science" can also include the study of how non-living things influence "life."

These tend to be difficult to address - for example, how does some ice melting in the Arctic (an "Earth Science" or "Climate Science" topic) affect an ecosystem (a life science topic) thousands of miles away? How does burning of a rainforest result in increased carbon dioxide levels in the ocean and how does that affect living things? How would a meteor the size of a VW car hitting Earth affect "life" on the planet? What happens to the human body (life science) during prolonged periods in space, exposed to solar radiation and less gravity (physical science)?What does breathing in smoke and ash to do a human lung? And how does a volcanic eruption like Mt St Helens affect the ecosystems locally and even globally?

I think that many people appreciate that non-living things can impact living organisms in dramatic ways and as such, that these aspects are necessarily part of "the study of life." Sometimes though, when we are teaching or learning, we tend to break everything down into more sizable chunks - we study volcanic eruptions as an aspect of earth science and we study a forest ecosystem and how the plants do photosynthesis as a life science. Eventually though, it must all come together! And I am guessing that this is the origin of your very thoughtful question! Try to remember this question every time you feel like you are studying something very specific - think about how that specific, really detailed topic, can relate to larger (and ultimately important) topics.

I guess the simple answer to your question would be yes. Life science is very broad. A biologist might study the basic building blocks of protein and how different combinations of these building blocks lead to different protein structures and functions. They might also look at different patterns in DNA and see how that affects biological function. They might look at structures at atomic level scales that may not be biological but can be used in a biological application. Someone in the life science might also study something a lot bigger like studying populations of animals. It's a very big field to be in with many different avenues to explore. It is also quite common in the life sciences to see a combination of different fields of study, even between life science and physical science (chemistry/physics/etc), to be able to come up with ways to solve problems.

I hope I have answered your question. :)

This question made me think for a while, and I came up with a few different answers. In general, the answer is yes: life science has to be about living things. However, I can think of some interesting exceptions. First, life scientists often study viruses, which aren't really alive. Well, we argue about whether they are alive - sometimes they seem to be, but since they can't reproduce on their own (they have to make host cells reproduce for them) we tend to think of them as almost alive, but not quite. So I would call that the 'trick question answer. Another answer is to look at ecology, which is the study of how organisms interact with each other and their environment. Ecologists are life scientists, but many of them spend most of their time thinking about things that aren't alive - soil chemistry, or oceanic currents, or sunlight, for example. Of course, they wouldn't study any of those things if they didn't have something to do with living things. My branch of science is similar - I am a mathematical biologist. So I use mathematical models and computer simulations to predict what animal populations would do. I could do my job perfectly well without ever actually looking at or dealing with any kind of real organism, but I think I probably wouldn't get paid if my boss didn't think that what I did related in some way to living things!