ecosystem
What is the term for all the living and non-living components in an environment interacting with each other?
a) Habitat
b) Community
c) Ecosystem
d) Biome
c) Ecosystem
The primary source of energy for most ecosystems is the Sun. Solar energy enters the food chain through photosynthesis, where plants (producers) convert sunlight into chemical energy. This energy is then passed on to herbivores (primary consumers) and other organisms in the food chain.
What is a food chain?
A food chain is a sequence of organisms where each one is eaten by the next organism in the chain. It shows how energy and nutrients flow from one organism to another, typically starting with a producer (like a plant) and moving through primary consumers (herbivores), secondary consumers (carnivores), and so on.
Which of the following is a producer in an ecosystem?
a) Rabbit
b) Fox
c) Grass
d) Mushroom
c) Grass
What happens to the amount of energy available in a food chain as you move up from one trophic level to the next?
As you move up trophic levels in a food chain, the amount of energy available decreases. Typically, only about 10% of the energy at one trophic level is transferred to the next level. The rest is lost as heat due to metabolism, movement, and other life processes.
What is the role of a producer in a food chain?
A producer (like a plant or algae) is the first link in the food chain. It creates its own food through photosynthesis and provides energy for herbivores (primary consumers) that eat it.
What is the primary source of energy for nearly all ecosystems on Earth?
a) Water
b) The Sun
c) Wind
d) Soil
b) The Sun
The 10% rule reflects the inefficiency of energy transfer between trophic levels. Most of the energy is lost as heat due to metabolic processes, such as respiration, movement, and digestion. Additionally, some energy is not consumed by the next trophic level (e.g., plant material that herbivores can't digest), and some is lost as waste.
How do food chains and food webs differ from each other?
A food chain shows a linear sequence of energy flow through a single pathway (from one organism to the next). In contrast, a food web is a more complex network of interconnected food chains, showing how different species in an ecosystem are related through multiple feeding relationships.
In a food web, what role do decomposers play?
a) They consume primary producers.
b) They break down dead organisms and recycle nutrients.
c) They are the primary consumers.
d) They act as top predators in the ecosystem.
b) They break down dead organisms and recycle nutrients.
A food chain is a linear sequence of energy transfer from one organism to another, typically from producers to consumers. In contrast, a food web is a more complex, interconnected system of multiple food chains. Food webs better represent real ecosystems because organisms often consume a variety of prey and are eaten by multiple predators, reflecting the diverse interactions that occur in nature. This complexity ensures that energy flow is more stable and less prone to disruption.
Why are decomposers important in a food web?
Decomposers (like fungi and bacteria) break down dead organic matter and waste products, returning essential nutrients to the soil or water. This process allows producers (like plants) to reuse these nutrients, making them available to the rest of the food web. Without decomposers, ecosystems would run out of nutrients.
Which biome is characterized by permafrost and extremely low temperatures, and is found primarily in the northern regions of the Earth?
a) Desert
b) Tundra
c) Tropical Rainforest
d) Savanna
b) Tundra
The removal of a keystone species can have a disproportionate effect on the ecosystem’s energy flow and stability. Keystone species play a critical role in maintaining the structure and diversity of the ecosystem. For example, if a top predator is removed, the populations of prey may increase dramatically, which could over-consume plants or smaller organisms, leading to imbalances. This disruption can cause cascading effects throughout the food web, reducing biodiversity and altering energy flow, potentially making the ecosystem less resilient to further changes.
How does the removal of a top predator (like a wolf) from a food web impact the ecosystem?
The removal of a top predator can have cascading effects throughout the food web. It may lead to an overpopulation of herbivores, which can result in overgrazing and depletion of plant life. This disruption can cause a shift in the structure of the entire ecosystem, affecting various species and their interactions. This is called a trophic cascade.