What Living Things Need

Activities to try

1. 1

   Side-by-side windowsill care bench

   Why it works: A need is proven by its consequence: withhold it and the living thing visibly suffers. Plants and animals need different things — plants need light and make their own food, animals cannot make food and must be fed.

   1. Set up (or run a model of) two living things to care for: a bean plant in a pot and a small animal such as a hamster in a hutch.
   2. Choose what to provide to each from a shared set of supplies: a watering can, a lamp for light, air, warmth, and a food bowl. With a real hamster, always give it everything it needs; only leave needs out in the model.
   3. Give the plant water but leave it in the dark, and watch over time (days, or time-compressed in a model) to see it stay alive but grow pale and leggy.
   4. Notice that the plant has NO food bowl and still grows, while the animal must be fed — then explain why the two lists differ.
   5. Rescue a wilting or pale plant by restoring the one missing need, and describe what changed.
2. 2

   Classroom split-plant fair test over a week

   Why it works: Changing only one variable (light) while keeping water, temperature and everything else as similar as possible shows that light is a genuine need for healthy growth: water alone is not enough.

   1. Plant two identical seedlings and give both equal water.
   2. Place one in a bright spot and cover the other with a lightproof box (or put it in a dark cupboard) in the same room, keeping water, pot, soil and temperature as similar as possible.
   3. Before the week passes, predict whether the dark seedling will grow as healthily (green and sturdy) as the light one, and say WHY. Remember a plant in the dark may grow taller but pale and floppy.
   4. Observe both plants over several days and record what changes.
   5. Compare the result to the prediction and state which need was missing from the weaker plant.
3. 3

   Name the needs and what uses them

   Why it works: Each need is linked to a part or behaviour of the organism and to a specific consequence if it is missing.

   1. Look at a plant and an animal and name each basic need aloud: for the plant — water, light, air, suitable temperature; for the animal — water, food, air, shelter/warmth.
   2. Pair each need with the part or behaviour that uses it, e.g. roots take up water, leaves use light, the animal's mouth takes in food.
   3. For each need, say what the living thing would look like if that need were missing (e.g. 'no water → wilts', 'no light → pale', 'no food → weak').