Test: Ecosystems - Grade 7 MCQ

Predation is characterized by one organism (the predator) hunting and consuming another organism (the prey). This relationship is fundamental in regulating populations and maintaining the balance within ecosystems.

Decomposers, such as bacteria and fungi, play a vital role in breaking down dead organic matter, recycling nutrients back into the soil. This process is essential for maintaining soil fertility and supporting new plant growth, thus sustaining the ecosystem.

Photosynthesis is the process where plants use sunlight, water, and carbon dioxide to create food in the form of glucose. This process is vital not only for the plants themselves but also for the entire ecosystem, as it forms the base of the food chain.

Climate change and human interference pose significant threats to ecosystems, leading to declines in biodiversity, habitat destruction, and resource shortages. Addressing these challenges is essential for preserving ecological balance and ensuring sustainable ecosystems.

Primary consumers, often herbivores, play the crucial role of feeding on producers (plants) to obtain energy. This relationship connects the plant-based producers to the meat-eating consumers further up the food chain, illustrating the flow of energy through an ecosystem.

Mutualism is a symbiotic relationship where both organisms benefit, as seen when a bird eats ticks off a cow. The bird gains food, while the cow enjoys relief from parasites, illustrating a cooperative interaction in nature.

Plants contribute to the ecosystem's balance by performing photosynthesis, which produces oxygen necessary for animal life and creates organic matter that serves as food for herbivores. This vital process supports life and maintains ecological stability.

All ecosystems, including deserts, aquatic environments, and forests, feature diverse flora and fauna that adapt to their specific climatic conditions. This diversity is essential for the resilience and stability of ecosystems worldwide.

An eagle is an example of a quaternary consumer, situated at the top of the food chain. Quaternary consumers often prey on tertiary consumers, and their presence indicates a healthy, balanced ecosystem with a diverse range of species.

Sunlight is the primary energy source for most ecosystems, driving the process of photosynthesis in plants. This energy is then transferred through various trophic levels, sustaining the entire food web within the ecosystem.

A snake is considered a tertiary consumer as it typically preys on secondary consumers like frogs or small birds. Tertiary consumers sit at a higher trophic level and help maintain the balance of the ecosystem by controlling the populations of their prey.

A food pyramid visually represents both the sequence of energy flow in food chains and the number of organisms at each trophic level. It typically shows that there are more producers at the base and fewer top consumers at the apex, highlighting energy loss at each trophic level.

Symbiosis refers to the interaction between two different organisms living in close physical proximity, often benefiting each other. This can take various forms, such as mutualism, commensalism, and parasitism, highlighting the interdependence of species in an ecosystem.

Biotic components refer to the living elements within an ecosystem, including plants, animals, and microorganisms. These organisms interact with each other and their environment, forming a complex network that sustains life. Understanding biotic components is crucial for studying ecological relationships.

Tropical rainforests, found in hot climates, are known for their dense canopy of evergreen trees. These forests host a rich diversity of flora and fauna, playing a crucial role in global biodiversity and climate regulation.

Soil plays a crucial role in supporting plant growth by providing a medium for roots and a reservoir of nutrients. It also facilitates nutrient cycling through the decomposition process, making it vital for maintaining the health of forest ecosystems.

When one food source is depleted in a food web, other food sources may still be available, allowing organisms to adapt and survive. This flexibility is a key benefit of food webs, making ecosystems more resilient to changes.

Food webs illustrate the complex interconnections between different food chains, allowing organisms to have multiple sources of food. This diversity strengthens the ecosystem's resilience, as it reduces dependency on a single food source.

Trees are biotic components, as they are living organisms. In contrast, water, soil, and sunlight are abiotic components that provide the necessary conditions for life and support the biotic components in an ecosystem.

Humans can aid in restoring and conserving ecosystems by creating a balance between living organisms and their environment. This involves respecting natural processes, conserving resources, and implementing sustainable practices, which are essential for preserving the integrity of ecosystems.