In biology, the theory which states that living organisms can arise only from pre existing living organisms and never from non living matter is known by which term?

Introduction / Context:
This question relates to the origin of life and classical biological theories about how living organisms arise. It asks you to identify the correct term for the idea that life always comes from pre existing life, which was central to the defeat of the old concept of spontaneous generation.

Given Data / Assumptions:
• The theory claims that living beings can arise only from other living beings.
• It explicitly denies the possibility of life arising directly from non living material in ordinary conditions.
• Several historical concepts about the origin of life are listed as options, including abiogenesis and panspermia.

Concept / Approach:
Biogenesis is the term that states life comes only from existing life. Experiments by scientists such as Louis Pasteur showed that microorganisms appear only when living germs are present, not spontaneously from sterile broth, supporting biogenesis. Abiogenesis, also known as spontaneous generation, is the opposite concept, suggesting life can appear directly from non living matter. Panspermia and cosmozoic theories suggest that life on Earth may have come from outer space. Catastrophism is a geological idea about sudden events shaping the Earth, not about the origin of life.

Step-by-Step Solution:
Step 1: Note the key phrase in the question statement, which is that living beings can arise only from other living beings. Step 2: Recall that biogenesis literally means origin from life, and it supports exactly this idea. Step 3: Recognise that abiogenesis is the name for spontaneous generation, which claims the opposite. Step 4: Eliminate panspermia and cosmozoic theories because they talk about seeds of life from space, not the general rule that life comes from life. Step 5: Conclude that the correct term is biogenesis.

Verification / Alternative check:
Standard biology textbooks define biogenesis as the principle that all living organisms arise from pre existing living organisms. They also describe experiments with sealed and open flasks of broth which conclusively supported biogenesis and refuted abiogenesis in the context of everyday life on Earth. This confirms that the term we need is biogenesis.

Why Other Options Are Wrong:
Abiogenesis: This is the idea of spontaneous generation, directly opposite to the statement in the question.
Catastrophism: A geological idea about sudden violent events shaping Earth history, unrelated to the origin of organisms.
Panspermia: Suggests that life originated elsewhere in the universe and arrived on Earth via meteorites or dust, not a rule that life always arises from existing life on Earth.
Cosmozoic theory: Similar to panspermia, proposing that germs of life came from space, not describing the routine origin of individual organisms.

Common Pitfalls:
Students often confuse biogenesis and abiogenesis because of the similar spelling. A helpful tip is to remember that the prefix bio refers to life and the root genesis means origin. Biogenesis is life from life, while abiogenesis uses the prefix a to denote absence, meaning life from non living matter. Keeping this word structure in mind avoids misselection in exams.

Final Answer:
The theory that living beings can arise only from other living beings is called Biogenesis.