NST1502 - Natural Science and Technology for classroom II
ASSIGNMENT 4 (PORTFOLIO)
DUE 2 October 2025
QUESTION 1
1.1 Define Kinetic energy. (2 marks)
ANSWER:
Kinetic energy is the energy possessed by an object due to its motion. The faster an
object moves, the greater its kinetic energy (Campbell & Reece, 2008).
1.2 Explain how energy is transferred in an ecosystem. (2 marks)
ANSWER:
Energy in an ecosystem is transferred through the food chain. Producers, such as
plants, capture energy from sunlight through photosynthesis. Consumers obtain energy
by feeding on producers or other consumers. Energy flows from one trophic level to
another, and some energy is lost as heat during metabolic processes (Odum, 2004).
1.3 What is the main purpose of photosynthesis in plants? (2 marks)
ANSWER:
The main purpose of photosynthesis is to convert light energy from the sun into
chemical energy stored in glucose molecules, which serves as fuel for plant growth and
cellular processes (Raven et al., 2005).
Disclaimer:
All materials are for study assistance only. We do not condone academic dishonesty. Use at your own risk.
We are not liable for any consequences arising from misuse.
Redistribution, resale, or sharing without permission is prohibited.
, 1.4 What is cellular respiration? (2 marks)
ANSWER:
Cellular respiration is the process by which cells break down glucose and other
molecules to produce energy in the form of ATP, while releasing carbon dioxide and
water as byproducts (Alberts et al., 2015).
1.5 Compare aerobic and anaerobic respiration. (4 marks)
ANSWER:
Feature Aerobic Respiration Anaerobic Respiration
Oxygen Requires oxygen Does not require oxygen
requirement
ATP yield Produces high amounts of ATP Produces low amounts of ATP (≈2
(≈36–38 ATP per glucose) ATP per glucose)
End products Carbon dioxide and water Lactic acid (in animals) or ethanol
and CO₂ (in plants/yeast)
Efficiency Highly efficient Less efficient
1.6 What is the role of ATP in cellular processes? (2 marks)
ANSWER:
ATP (adenosine triphosphate) serves as the primary energy currency of the cell,
providing energy for processes such as muscle contraction, active transport, and
biochemical reactions (Nelson & Cox, 2017).
Disclaimer:
All materials are for study assistance only. We do not condone academic dishonesty. Use at your own risk.
We are not liable for any consequences arising from misuse.
Redistribution, resale, or sharing without permission is prohibited.
ASSIGNMENT 4 (PORTFOLIO)
DUE 2 October 2025
QUESTION 1
1.1 Define Kinetic energy. (2 marks)
ANSWER:
Kinetic energy is the energy possessed by an object due to its motion. The faster an
object moves, the greater its kinetic energy (Campbell & Reece, 2008).
1.2 Explain how energy is transferred in an ecosystem. (2 marks)
ANSWER:
Energy in an ecosystem is transferred through the food chain. Producers, such as
plants, capture energy from sunlight through photosynthesis. Consumers obtain energy
by feeding on producers or other consumers. Energy flows from one trophic level to
another, and some energy is lost as heat during metabolic processes (Odum, 2004).
1.3 What is the main purpose of photosynthesis in plants? (2 marks)
ANSWER:
The main purpose of photosynthesis is to convert light energy from the sun into
chemical energy stored in glucose molecules, which serves as fuel for plant growth and
cellular processes (Raven et al., 2005).
Disclaimer:
All materials are for study assistance only. We do not condone academic dishonesty. Use at your own risk.
We are not liable for any consequences arising from misuse.
Redistribution, resale, or sharing without permission is prohibited.
, 1.4 What is cellular respiration? (2 marks)
ANSWER:
Cellular respiration is the process by which cells break down glucose and other
molecules to produce energy in the form of ATP, while releasing carbon dioxide and
water as byproducts (Alberts et al., 2015).
1.5 Compare aerobic and anaerobic respiration. (4 marks)
ANSWER:
Feature Aerobic Respiration Anaerobic Respiration
Oxygen Requires oxygen Does not require oxygen
requirement
ATP yield Produces high amounts of ATP Produces low amounts of ATP (≈2
(≈36–38 ATP per glucose) ATP per glucose)
End products Carbon dioxide and water Lactic acid (in animals) or ethanol
and CO₂ (in plants/yeast)
Efficiency Highly efficient Less efficient
1.6 What is the role of ATP in cellular processes? (2 marks)
ANSWER:
ATP (adenosine triphosphate) serves as the primary energy currency of the cell,
providing energy for processes such as muscle contraction, active transport, and
biochemical reactions (Nelson & Cox, 2017).
Disclaimer:
All materials are for study assistance only. We do not condone academic dishonesty. Use at your own risk.
We are not liable for any consequences arising from misuse.
Redistribution, resale, or sharing without permission is prohibited.
