A scientist took four containers, each containing 100g of dead plants. The scientist added decomposers to each container for 30 days. The table shows the results. (a) Which variable did the scientist change? (b) State two variables that should be kept the same. (c) Which variable did the scientist measure? (d) Use the evidence in the table to make a conclusion.

(a) The scientist changes the variable of temperature. (b) The two variable that should be kept the same is the dead plants and decomposers. Decomposers break down the organic matter into nutrient (carbohydrate, protein, etc). (c) The scientist measures the mass of plant material. (d) By observing the result we can say that microorganisms can grow rapidly in low temperature. They break down the organic matter of dead plants faster.

E M B I B E

Cambridge Lower Secondary Science Stage 7 : Student's Book>Chapter 2 - Microorganisms and Disease>Exercise 19>Q 5

MEDIUM

Lower Secondary Stage 7

IMPORTANT

Earn 100

Explain why decomposers are important.

Important Questions on Microorganisms and Disease

HARD

Lower Secondary Stage 7

IMPORTANT

Cambridge Lower Secondary Science Stage 7 : Student's Book>Chapter 2 - Microorganisms and Disease>Exercise 19>Q 6

A scientist took four containers, each containing 100g of dead plants. The scientist added decomposers to each container for 30 days. The table shows the results.

Question Image

(a) Which variable did the scientist change?

(b) State two variables that should be kept the same.

(c) Which variable did the scientist measure?

(d) Use the evidence in the table to make a conclusion.

HARD

Lower Secondary Stage 7

IMPORTANT

Cambridge Lower Secondary Science Stage 7 : Student's Book>Chapter 2 - Microorganisms and Disease>Exercise 19>Q 7

Unleavened bread, such as AI Jajab bread eaten in the United Arab Emirates, is made without yeast. Suggest a difference between AI Jajab bread and the bread in figure 2.14. Explain your reasoning.

Question Image