Assignment 4
Portfolio
Due 2 October 2025
, NST1502
Assignment 4
PORTFOLIO
DUE 2 October 2025
Question 1
1.1 Define Kinetic energy.
Kinetic energy is the energy an object has because of its motion. It depends on both mass
and velocity, expressed mathematically as:
𝟏
𝑲𝑬 = 𝒎𝒗𝟐
𝟐
where m represents mass and v velocity (Serway & Jewett, 2018).
1.2 Explain how energy is transferred in an ecosystem.
Energy flows through ecosystems in one direction, beginning with producers that capture
sunlight through photosynthesis. Herbivores obtain this energy by eating plants, which is
then transferred to carnivores and decomposers. At each stage, some energy is lost as heat,
which makes the system dependent on continual solar input (Odum & Barrett, 2005).
1.3 What is the main purpose of photosynthesis in plants?
Photosynthesis enables plants to transform sunlight into glucose, which stores energy for
growth and reproduction. This process also sustains entire food webs by supplying the
primary energy source for all other organisms (Taiz et al., 2015).
1.4 What is cellular respiration?
Cellular respiration is the process in which cells break down glucose to release energy in
the form of ATP. This energy fuels essential biological functions, including active transport
and biosynthesis (Nelson & Cox, 2017).