30 Questions
What is an ecosystem composed of?
Both biotic and abiotic factors
What is the primary purpose of a habitat?
To provide food, water, shelter, and living space for an organism
What is the role of a niche in an ecosystem?
To define the special role an organism plays within its ecosystem
What can ecosystems be composed of?
Smaller ecosystems and habitats
Why do different species of organisms occupy different niches?
To minimize competition for resources
What is a reason why lions and cheetahs can coexist?
They occupy different niches
What is an example of density-independent factors that can affect population density?
Extreme weather
What is true about the heron and the egret?
They have similar feeding habits but different breeding seasons
What is population density?
The number of species living within a specific size of an area
What is an example of a density-dependent factor that can affect population density?
Competition for resources
What is the main role of a niche in an ecosystem?
To define the unique role of an organism within its ecosystem
What is the primary reason why species in a given ecosystem do not share niches?
Because they compete with each other for resources
What determines the niche an animal occupies in its ecosystem?
Its living habits, such as how, what, when, and where it eats and finds shelter
Why do giraffes not compete with other herbivores for food in the Serengeti ecosystem?
Because they are able to access food that others are unable to reach
What is the result of competition between organisms that have the same exact needs within an ecosystem?
One dies off or changes enough that it no longer competes
What is the primary function of a food chain in an ecosystem?
To represent the feeding interactions between organisms
What is the source of energy for aquatic plants in a freshwater lake ecosystem?
The energy from the sun through photosynthesis
What happens to the energy contained in aquatic plants when they are eaten by stonefly larva?
The energy is transferred to the stonefly larva
What is the direction of energy flow in a food chain?
From prey to predator
What is the direction of energy flow in a food chain?
From organism to organism, in only one direction
What is true about the relationship between organisms in a food chain?
Each organism is either a predator or a prey
What is the role of autotrophs in an ecosystem?
To create or produce their own food
What is the term for organisms that feed on both plants and animals?
Omnivore
What is the trophic level of organisms that feed on secondary consumers?
Tertiary Consumer
What is the term for the highest trophic level in a food chain?
Quaternary Consumer
What do food webs represent in an ecosystem?
All of the food chains within an ecosystem and their interconnected feeding relationships
How does energy flow through an ecosystem?
In an upward trend from producers to quaternary consumers, with some energy lost between levels
What percentage of energy is transferred from one trophic level to the next in a food web?
10%
Why is energy lost between trophic levels in a food web?
Due to heat, metabolism, and unused matter
What happens to the energy that is not transferred to the next trophic level in a food web?
It is lost due to heat, metabolism, or unused matter
Study Notes
Ecosystem, Habitat, and Niche
- An ecosystem is the interaction between all biotic (living) and abiotic (non-living) factors within a geographic area.
- Ecosystems vary in size, location, and diversity, and are dynamic places made of interrelated and interacting factors.
- A habitat is the natural home or place within an ecosystem that provides the kind of food, water, shelter, and living space an organism needs to survive.
- A niche is the special role an organism plays within its ecosystem, or the very specific conditions it takes advantage of, and different species occupy different niches to minimize competition.
Habitat Examples
- The Serengeti-Mara ecosystem is a large open and wooded grassland savanna habitat located in east-central Africa, characterized by a seasonal tropical climate, volcanic ash-based soil, and seasonal fires.
- The Serengeti-Mara ecosystem has a variety of habitats, including grasslands, wooded areas, and wetlands, each with its own unique characteristics and niches.
Niche Examples
- In the Serengeti-Mara ecosystem, lions hunt wildebeests, while cheetahs hunt smaller prey like antelopes and gazelles, each occupying a different niche.
- Herbivores like wildebeests, zebras, gazelles, and antelopes each have their own niche, preferring different types of food, such as short grasses, herbs, shrubs, leaves, or long grasses.
- Giraffes have a unique niche, able to access food that others cannot reach.
Population Density
- In biology, a population is a group of organisms of the same species living within an area.
- Population density refers to the number of species living within a specific size of an area.
- Factors that affect population density include density-dependent factors, such as disease, competition for resources, predation, and environmental degradation, and density-independent factors, such as extreme weather, natural events, fire, pollution, and seasonal weather changes.
Learn about ecosystems, habitats, and niches in biology, including the interactions between living and non-living factors, habitat examples, and niche examples in the Serengeti-Mara ecosystem. Understand population density and the factors that affect it.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
