Question 1
Which of the following best explains why fire is NOT considered a living thing, even though it moves and grows?No clue? Show me the answer
Correct answerCorrect!
IncorrectStep-by-step walkthrough
Choose a solution method
Method #1Direct ApproachStep 1: Recall the criteria for life
All living things must display all seven characteristics described by MRS GREN: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, and Nutrition.
Step 2: Check fire against MRS GREN
Fire does move, it does 'grow' in size, and it needs oxygen (a form of respiration). However, fire cannot reproduce — it cannot produce offspring — and it does not excrete biological waste products.
Step 3: Choose the correct answer
Because fire fails at least two of the seven characteristics (reproduction and excretion), it is not considered alive. The correct answer is: fire cannot reproduce or excrete waste in a biological sense.
Method #2Process of EliminationStep 1: Identify what is being asked
The question asks why fire does not qualify as a living thing despite showing some life-like behaviours.
Step 2: Eliminate 'Fire does not need oxygen'
This is incorrect — fire does need oxygen to burn. Eliminating this option.
Step 3: Eliminate 'Fire does not move or change in size'
This is clearly false — flames visibly move and a fire can spread and grow. Eliminating this option.
Step 4: Eliminate 'Fire is made of chemicals'
All living things are also made of chemicals, so this reasoning does not distinguish living from non-living. Eliminating this option.
Step 5: Select the correct answer
The remaining option — fire cannot reproduce or excrete waste in a biological sense — correctly identifies the missing MRS GREN characteristics that disqualify fire from being alive.
Question 2
A sunflower slowly turns its stem and leaves to face the Sun throughout the day. Which characteristic of living things does this best demonstrate?No clue? Show me the answer
Correct answerCorrect!IncorrectStep-by-step walkthrough
Choose a solution method
Method #1Direct ApproachStep 1: Identify the behaviour described
The sunflower is detecting a change in its environment (the position of the Sun) and responding to it by turning. This behaviour is called phototropism.
Step 2: Match the behaviour to MRS GREN
Sensitivity is defined as the ability to detect and respond to changes in the environment. The sunflower is clearly detecting sunlight and responding by moving — this fits sensitivity perfectly.
Step 3: Select the correct answer
The correct answer is Sensitivity.
Method #2Process of EliminationStep 1: Identify what is being asked
The question asks which MRS GREN characteristic is shown by a sunflower tracking the Sun.
Step 2: Eliminate 'Nutrition'
Nutrition refers to obtaining food or energy, not to physically moving in response to light. Eliminating this option.
Step 3: Eliminate 'Excretion'
Excretion means removing waste products from the body — unrelated to tracking sunlight. Eliminating this option.
Step 4: Eliminate 'Reproduction'
Reproduction means producing offspring — the sunflower is not producing seeds in this scenario. Eliminating this option.
Step 5: Select the correct answer
Sensitivity — detecting and responding to changes in the environment — is the only remaining option and correctly describes the sunflower's behaviour.
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