A life process is one of the activities that all living organisms carry out. No single observation proves that something is alive. You need evidence for several processes together. Questions on this appear early in living systems and classification and set up every later topic.
What are the seven life processes?
Learn each one with a short, exact meaning and one everyday example.
| Process | Plain meaning | Example |
|---|---|---|
| Movement | An organism or part of it changes position or place | A sunflower head turns, a snail glides |
| Respiration | Chemical reactions in cells that release energy from food | Muscle cells releasing energy to contract |
| Sensitivity | Detecting a change in the surroundings and responding | A root growing towards water |
| Growth | A permanent increase in size and dry mass | A seedling becoming a taller plant |
| Reproduction | Making more organisms of the same kind | A plant producing seeds |
| Excretion | Removing waste made by the organism’s own chemistry, and excess substances | Carbon dioxide leaving a leaf or a lung |
| Nutrition | Taking in materials for energy, growth and repair | A plant taking in carbon dioxide and water, an animal eating |
A memory aid such as “MRS GREN” is fine. The exam rewards the meaning, not the acronym.
Why is one observation not enough?
Many non-living things copy one feature. A leaf blown along a path moves, but the wind moves it. A candle flame uses oxygen and releases energy, but it does not grow cells or reproduce.
Also, a living thing can look inactive. A dry seed shows almost nothing for weeks, yet it is alive. So the rule is: collect evidence for several processes, and judge the pattern.
Worked example
A student finds a hard, grey, bean-shaped object in a drawer and records what happens over one week in a moist tray. These readings are invented for practice.
| Day | Observation |
|---|---|
| 1 | Hard, dry, does not move |
| 3 | Swollen and softer |
| 5 | A small white structure emerges |
| 7 | A green shoot bends towards a window |
Step 1, test each observation. Swelling alone is not good evidence, because dry sponge also swells when wet. So Day 3 is weak evidence.
Step 2, link the rest to a process. A structure emerging and becoming larger shows growth. A shoot bending towards light shows sensitivity and a change of position.
Step 3, decide. Two or more life processes are shown, so the object is very likely a seed, which is living. A follow-up test, such as sealing it in a tube and detecting carbon dioxide released, would add respiration.
Answer: the object is alive, because growth and sensitivity are both shown, not because it swelled.
The mistake to watch for
Mistaken answer: “The object moved on Day 3, so it is alive.”
Movement caused by something else, such as swelling with water or being pushed, does not count.
The correction is to ask two questions. Is the change produced by the organism itself, and is it backed by at least one more life process? If either answer is no, do not claim that the object is alive.
Check yourself
1. A rock in a rock pool is slowly pushed along by waves. Name the life process this might be confused with, and explain why it does not count.
Show answer
It might be confused with movement. It does not count because the rock is moved by an outside force and does not carry out any other life process.
2. A plant on a windowsill is kept in the dark for three days. Its leaves curl and it stops growing. Which two life processes link most directly to these observations?
Show answer
Growth stopped, and the leaves responded to the change in conditions, which is sensitivity. The question may also accept nutrition, because without light the plant cannot make food.
3. A student says, “Crystals grow in a salt solution, so crystals are alive.” Give one reason the conclusion is weak.
Show answer
Crystals increase in size by adding material from outside, but they do not respire, excrete, reproduce or respond to stimuli. One matching process is not enough.
Where this leads next
Next, see how the features you observe are turned into a sorting tool in using a simple identification key. When you have covered the whole module, try the living systems and classification practice set.
Some students can recall every definition and still lose marks when a question describes something unfamiliar. That is a pattern our teachers look for in online one-to-one Biology tuition.