Question 1

What is energy flow in an ecosystem according to the Cambridge IGCSE Biology curriculum?

Accepted Answer

Energy flow in an ecosystem refers to the transfer of energy through a food chain from primary producers to various consumers. In the Cambridge IGCSE Biology curriculum, it is emphasized that energy originates from the sun and is captured by plants through photosynthesis. This energy is then passed on to herbivores, and subsequently to carnivores and decomposers, with energy being lost as heat at each trophic level.

Question 2

How does energy flow differ from nutrient cycling in ecosystems?

Accepted Answer

Energy flow and nutrient cycling are both crucial processes in ecosystems, but they differ significantly. Energy flow is a one-way process where energy from the sun is captured by producers and transferred through the food chain, eventually being lost as heat. In contrast, nutrient cycling involves the recycling of nutrients like carbon and nitrogen within the ecosystem, allowing them to be reused by different organisms. This distinction is important in understanding ecosystem dynamics in the Cambridge IGCSE Biology syllabus.

Question 3

Why is energy transfer between trophic levels inefficient?

Accepted Answer

Energy transfer between trophic levels is inefficient because a significant amount of energy is lost at each level, primarily as heat due to metabolic processes. According to the Cambridge IGCSE Biology curriculum, only about 10% of the energy is passed on to the next trophic level, while the rest is used for life processes like movement, growth, and reproduction, or lost as heat. This inefficiency limits the number of trophic levels in an ecosystem.

Question 4

What role do decomposers play in the energy flow of an ecosystem?

Accepted Answer

Decomposers, such as bacteria and fungi, play a crucial role in the energy flow of an ecosystem by breaking down dead organisms and organic waste. This process releases nutrients back into the soil, making them available for primary producers. While decomposers do not directly transfer energy to higher trophic levels, they facilitate the recycling of nutrients, which supports the energy flow by maintaining the health and productivity of the ecosystem, as outlined in the Cambridge IGCSE Biology curriculum.

Question 5

How does the concept of a food chain illustrate energy flow in an ecosystem?

Accepted Answer

A food chain is a linear sequence that illustrates how energy flows from one organism to another within an ecosystem. It begins with primary producers, such as plants, which capture solar energy through photosynthesis. This energy is then transferred to herbivores, and subsequently to carnivores and apex predators. The Cambridge IGCSE Biology curriculum uses food chains to demonstrate the direction and efficiency of energy transfer, highlighting the loss of energy at each trophic level.

Energy Flow

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