What Is Life?
So you’re probably wondering what life is, right? I mean, as a species we’ve been asking ourselves this question for at least 20,000 years. At some point in history, it seems like everyone was trying to figure out what makes us tick—why we exist and what makes life worth living. But if you’ve ever wondered why we ask ourselves such existential questions, especially when it comes to our own existence as living things on this planet Earth (or other planets), then read on!
Life is a characteristic that distinguishes physical entities that have biological processes, such as signaling and self-sustaining processes, from those that do not, either because such functions have ceased (they have died), or because they never had such functions and are classified as inanimate.
Life is defined as: “a self-sustaining organization of matter” (Bertalanffy). It is also used to describe living organisms in general.
Biology is the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy.
Biology is the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution and taxonomy. The term “biology” refers to the scientific field of life sciences or to a particular branch of such a field (e.g., botany). In modern usage, the term “biochemistry” is often used as a synonym for “chemistry.” “Biochemistry” is a special section in an introductory textbook on organic chemistry.
Living organisms undergo metabolism, maintain homeostasis, can grow, respond to stimuli, reproduce and adapt to their environment in consecutive generations.
Living organisms undergo metabolism, maintain homeostasis, can grow, respond to stimuli and reproduce in consecutive generations. Metabolism is the sum of all chemical reactions occurring in an organism or cell that involve molecules being used as fuel (ATP). Homeostasis is the ability of an organism or cell to maintain its internal environment at a constant state despite fluctuations in external conditions. Growth refers to any increase in size or mass. It specifically refers to changes over time. These changes occur when living organisms are exposed to food sources or other forms of energy (such as sunlight), for which their bodies have been modified by natural selection over many generations through evolution. Responses include movement toward light sources so they can photosynthesize. It can be movement away from those same lights because they’ve been eaten. Or changing shape due to environmental cues such as wind direction; etc.,
“Reproduction involves passing genes from one generation into another by either sexual means (meiosis) or via mitosis, where cells divide without having any new proteins and inherit genetic information from parent cells.”
A diverse array of living organisms present in the biosphere on Earth, and the properties common to these organisms—plants, animals, fungi, protists and bacteria—are a carbon-and-water based cellular form with complex organisation and heritable genetic information.
Cells are the basic unit of life. They have a nucleus and membrane, which enclose the genetic material (genome) for that cell. The genome contains all the necessary information for each individual cell. It has its own unique copy of this DNA molecule within each cell.
Cells carry out essential functions for life. Respiration converts food into energy. Reproduction produces offspring. Movement allows organisms to move around in their environment. For example, by walking or swimming through water. Digestion breaks down food into simpler molecules. So, cell membranes absorb them into their interior structures. The body uses this energy to perform its functions.
We’re still trying to figure it out.
We are still trying to figure out life. We have a lot of questions, and we don’t know everything about it. But we do know that we’re still in the process of understanding life—and that’s something!
We’ve come a long way since our first moments on earth, when our bodies were made up of nothing but cells. Those cells combine to make tissues, organs, and systems that help keep us alive. There are many different ways for humans to die (some more common than others). Everyone dies at some point during their lifetime. So no matter where you live or what your nationality is, death will likely be part of your life story someday too!
So, what is life? We don’t yet know the answer to that question. But we do know one thing: Life is beautiful, complex and diverse. And if you’re looking for more information on how we study biology at MIT (or anywhere else), check out our website at http://www.bio.mit.edu/people/faculty-staff/biologists/.
Read More Lifehacks for lazy people