Food Chains
What is the original source of energy for almost all food chains on Earth?
The Sun
What is a food web?
A network of interconnected food chains showing many feeding relationships in an ecosystem.
What do we call the largest population size that an environment can support?
Carrying capacity
What level of the food chain contains the most available energy?
Producers
What type of organism makes its own food using sunlight?
Producer/ Autotroph
If one species in a food web disappears, what usually happens to the rest of the web?
Other populations are affected because food sources and predator relationships change.
When a population grows slowly at first, then quickly, and then levels off, what type of growth curve does it show?
Logistic growth
What process do plants use to convert sunlight into chemical energy?
Photosynthesis
In the following chain — grass → grasshopper → frog → snake → hawk — which organism is the secondary consumer?
The frog
Why are top predators important in maintaining balance in food webs?
They control prey populations and prevent overgrazing or overpopulation.
What are the two main types of limiting factors that control population growth?
Density-dependent and density-independent factors
What term describes a close relationship between two species, such as mutualism or parasitism?
Symbiosis
What do we call an organism that eats both plants and animals?
Omnivore
In a food web, arrows point in which direction — toward the energy source or toward the organism receiving energy?
oward the organism receiving energy (shows energy flow).
Give one example of a density-dependent limiting factor.
Predation, competition, or disease
What type of succession occurs after a forest fire?
Secondary succession
Why are decomposers essential to food chains and webs?
They break down dead organisms and return nutrients to the soil for producers to reuse.
How can introducing a new species disrupt a food web?
It can outcompete native species or alter the balance of existing food chains.
Explain what happens to a predator population when its prey population decreases sharply.
The predator population also decreases due to lack of food and increased competition.
A population of rabbits increases rapidly after being introduced to a new area with no predators. What type of growth is this?
Exponential growth