Year 7 Science · Unit 1 · Lesson 1
Foundation Worksheet
Learning Goals
Fill the gap
Choose the correct word from the word bank. Each word is used once. One word is not needed: cross it out.
Scientists use a checklist of seven characteristics to decide whether something is alive. The name MRS GREN helps us remember them. M stands for : an organism can move part or all of its body, and plants do this slowly when they bend toward light. R stands for , a chemical reaction inside that releases energy from food. This is not the same as , which only moves air in and out of the lungs. S stands for , detecting and reacting to a change in the surroundings. G stands for : getting bigger or more complex over time. The second R stands for : the species can produce new members, though an individual does not need to reproduce. E stands for , removing waste chemicals made by the body. N stands for , taking in food or making it using sunlight. Together, MRS GREN describes life processes and capacities across an organism's life; not all need to be visible at once.
True or false? Fix the false ones
Circle T or F. If a statement is false, correct it on the line.
1. All living things are made of at least one cell.
Correct it:
2. Viruses are made of cells, just like bacteria.
Correct it:
3. Plants are not alive because they cannot move from place to place.
Correct it:
4. A fallen gum leaf is dead, not non-living, because it was once part of a living tree.
Correct it:
Sort it
Ask “Was this ever alive?” Then write each item in the correct box. The boxes do not hold the same number of items.
Living
Dead
Non-living
1. Explain the difference between a dead thing and a non-living thing. Give one example of each that is not in the sort above.
Read the data
Scenario: four mystery samples
A science team collects four samples from a cave. They check each one with a microscope and watch it for two weeks. Table 1 shows what they saw.
| Sample | Made of cells? | Life processes observed and capacities shown in two weeks |
|---|---|---|
| A | Yes, but its cells are dried out and irreversibly broken | None; the damage cannot be reversed |
| B | No | Growth only: it got bigger as salty water dripped onto it |
| C | No | Reproduction only, and only once it was inside the cells of a living bat |
| D | Yes | Active life processes; belongs to a species that reproduces |
Source: made-up samples for this worksheet.
2. Classify samples A, B and D as living, dead or non-living. Give one reason from Table 1 for each.
3. Sample C behaves like a virus. Should the team call it alive? Use Table 1 to explain.
4. Lucas says: “A bushfire is alive. It moves, it grows and it eats fuel.” Use MRS GREN to explain whether Lucas is right.
Fill the gap
movement; respiration; cells; breathing; sensitivity; growth; reproduction; excretion; nutrition. Not used: photosynthesis.
True or false
1. True. 2. False: viruses are not made of cells; a virus is genetic material inside a protein coat. 3. False: plants move parts of themselves (stems bend toward light, flowers open and close); they show all seven characteristics. 4. True.
Sort it
Living: a platypus; a mushroom growing on a log; a wattle seedling. Dead: a leather belt (animal skin); a paper bag (wood); a cotton T-shirt (cotton plant). Non-living: a sandstone block; a steel nail; an ice cube.
Question 1
A dead thing was once alive but can no longer carry out its life processes (1); a non-living thing was never alive (1). One correct new example of each, for example dead: a fossil or a feather; non-living: a rock or air (1). [3 marks]
Question 2
A is dead: it was made of cells, but those cells are irreversibly damaged and cannot resume life processes (1). B is non-living: no cells, and growth alone is not enough; it is like a crystal (1). D is living: it is made of cells and shows several life processes; its species can reproduce (1). [3 marks]
Question 3
No (or: it sits at the edge of life). It is not made of cells (1) and shows only one of the seven characteristics, and only inside a host’s cells (1). [2 marks]
Question 4
Marking guide: 1 clear position (Lucas is wrong); 1 for stating a fire is a chemical reaction with no cells, not an organism; 1 each for two characteristics fire lacks with a reason (cannot reproduce offspring of its own kind; no sensitivity, as it does not detect and respond to a stimulus; no excretion from a body); 1 for explaining that MRS GREN is considered as a set of capacities across an organism's life; not every process must be visible at once, and reproduction is a species-level capacity. [5 marks]
Model answer: Lucas is wrong. A fire spreads and uses fuel and oxygen, but it is a chemical reaction, not an organism. It has no cells, it does not reproduce its own kind and it does not sense a stimulus. Rivers and crystals also show one or two characteristics; MRS GREN is a set of life processes and capacities considered across an organism's life, including reproduction at the species level.
Common error: counting one characteristic, such as movement or growth, as proof of life.