SECTION 5 QUESTION 2
21. The diagram below shows the apparatus used to investigate the rate of photosynthesis in a
submerged plant. The light intensity to which the plant is subjected, was decreased at regular
Intervals by moving the light source away from the plant. The average number of bubbles released
pet minute, was counted and recorded for each distance.
study the information provided and answer the questions that follow.
The results obtained is shown in the following table.
Distance from lamp (cm)
5
10
20
25
35
40
50
Number of bubbles per minute.
70
65
40
25
15
5
2
2.1.1. Formulate a hypothesis for the above investigation.
2.12. Slate the following
(1) Dependent variable
(2) independent variable
(3) Fixed variable
2.1.3. State ONE way in which the reliability of the investigation could be improved.
2.1.4. Draw a line graph to represent the data in the table
(13)​

Archeologists have discovered three sites showing conclusive evidence for the mastery of fire in tanzania, from a period slightly after the time that homo habilis was present in africa. these sites clearly were founded by homo erectus, the descendent species of homo habilis that migrated north, out of africa and into asia. homo erectus was known to have mastered fire, from ample evidence at sites in asia. there is no reason to attribute mastery of fire to homo ergaster, the descendent species of homo habilis that remained in africa.which of the following is an assumption on which the argument depends? (a) before their migration, homo erectus occupied african territory as far south as tanzania.(b) the strain of migration provided the selective pressure motivating homo erectus‘ mastery of fire.(c) homo ergaster would not have derived as much benefit from the mastery of fire as did homo erectus.(d) homo ergaster inherited all cultural knowledge from homo habilis, a species that did not have mastery of fire.(e) homo ergaster did not occupy regions as far south as tanzania until well after the time of these three sites.