56456679 science exercise year 5
TRANSCRIPT
Salin latihan ini ke dalam buku sains 2 (SC2)
1 A group of pupils carried out an investigation to find out if microorganisms can grow. They took a slice of bread and sprinkled a few drops of water on it. The moist bread was put into a clear plastic bag and then left for one week. The result of the experiment is shown in Diagram 1.
Diagram 1
(a) What is the purpose (aim) of the investigation?
___________________________________(b) State one relationship (hypothesis) between the day and size of dark spot.
___________________________________
(c) Identify the dark spots.
___________________________________
(d) Suggest one way to prevent the bread from getting spoilt very fast.
___________________________________
(e) Give two uses of the useful microorganisms.
1. _________________________________
2. _________________________________
Some microorganisms are very useful to mankind.
(f) State the conclusion that can be made based on the observation.
____________________________________
2 An investigation has been carried out by the following steps.1. Mix one teaspoon of sugar and two teaspoons of dried yeast with some water in a conical flask.2. Insert a balloon over the mouth of the conical flask.3. Left outside in a warm place for 20 minutes.Diagram 2 shows the conical flask containing warm water, yeast and sugar.
Diagram 2
(a) Predict what will happen after 20 minutes of investigation.
____________________________________
(b) State one reason (inference) based on your answer in (a).
____________________________________
(c) State another observation that can be found after 20 minutes.
____________________________________
(d) State one reason (inference) based on your answer in (c).
____________________________________
(e) What can be concluded in the investigation?
___________________________________
3 The following shows a conversation between a doctor and a patient.
(a) What would X most probably be?
_______________________________________
(b) State another symptom that the patient could have faced.
___________________________________(c) What is the possible cause of the disease X?
___________________________________ [1 mark]
(d) How does this disease spread?
___________________________________ [1 mark]
(e) State two ways to prevent microorganisms from
spreading.
1.__________________________________
2.__________________________________[2 marks]
(f) State two possible contagious diseases which can be Y.
1. _________________________________
2. _________________________________[2 marks]
Patient: There are itchy red spots on my skin all over my body.
Doctor: You are infected with a disease called X. I will give you an injection and you will be alright in two days time.
Patient: Thank you, doctor.
A patient who is infected with contagious disease Y is being quarantined in a hospital.