Energy Management Objective Questions & Answers on “Food Webs”.
1. Why is a food web more realistic way of portraying an ecosystem than a food chain?
a) Because it shows the relation of organisms with each other in a habitat
b) Because food chains use only a small sampling of organisms
c) Because it doesn’t shows the relation of organisms with each other in a habitat
d) Because it compares the number of consumers to the number of micro-organisms.
Answer: a
Clarification: Food web is more realistic due to the fact that we can add more organisms into the mix and show how they interact with each other in an ecosystem. In food chain we are just doing a small segment of about three or four animals in a basic food chain.
2. What is called for an organism that helps to define an entire ecosystem?
a) Super species
b) Keystone species
c) Dominant species
d) Precious species
Answer: b
Clarification: Keystone species have low functional redundancy. Any organisms from plants to fungi can be a keystone species. They are not always most abundant species in an ecosystem. The way animals influence food webs varies from habitat to habitat.
3. What is called for the diagram that shows how food chain linked together into more complex feeding relationship?
a) Food web
b) Food chain
c) Food circle
d) Food triangle
Answer: a
Clarification: A food web consists of all the food chains in a single ecosystem. All the interconnected and overlapping food chains in an ecosystem make up a food web. Unlike a food chain, organisms in food web occupy more than one trophic level.
4. Which of the following condition is true for food web?
a) A food web only follows just one path
b) A food web ends with a producer
c) A food web starts with a consumer
d) A food web shoes many paths plants and animals connected.
Answer: d
Clarification: In food web we find many different paths on plants and animals which are connected to each other. In food web producer are connected to consumers and consumers are connected to decomposers in a specific order.
5. Which one of the following is the major difference between food web and food chain?
a) Food chain and food web are linear pathway
b) Food chain and food web are interconnected pathway
c) Food chain is a single linear pathway and food web is interconnected pathway
d) Food chain is interconnected pathway through which food web is single linear pathway
Answer: c
Clarification: Food chain is a single linear pathway through which food energy and nutrients travel in the ecosystem while food web is number of interconnected food chains through which energy along with nutrients travels in the ecosystem.
6. Food webs derive their energy from sunlight.
a) True
b) False
Answer: a
Clarification: Most food webs on Earth derive their energy primarily from sunlight. This energy is captured by plants via photosynthesis and then distributed to the consumers in the environment. A food web used that energy and those energy proceeds to the succeeding organisms.
7. In which of the following we can have more than one source of organisms for energy?
a) Food chain
b) Food web
c) Food circle
d) Food rotation
Answer: b
Clarification: In pond ecosystem, an algae which are a producer is a food for many organisms present in the pond. For example prawn, carp which are all primary consumers eat algae in order to get energy. Thus a single producer feeds many consumers.
8. Which of the following is the highest trophic level organism in grassland food web?
a) Grass
b) Grasshopper
c) Lizard
d) Hawk
Answer: d
Clarification: In grassland trophic level grass is the producer. Grasshopper belongs to primary consumer. Lizard which eats grasshopper belongs to secondary consumer. Hawk belongs to tertiary consumer since it eats lizards.
9. Which of the following is correct order of food web for aquatic food web?
a) Diatoms->pteropods->lantern fish->squid->marlin
b) Diatoms->lantern fish->squid->marlin->pteropods
c) Lantern fish-> diatoms-> squid-> marlin->pteropods
d) Lantern fish-> diatoms-> squid-> pteropods-> marlin
Answer: a
Clarification: In aquatic food web diatoms is phytoplankton where the food web process starts. Pteropods are zooplankton. Lantern fish is the filterers. Squid is the predator followed by marlin which is top predator in aquatic food web.
10. Why large sharks remain in the highest trophic level in the aquatic food web?
a) Because large sharks are predators
b) Because large sharks are top predators
c) Because large sharks are phytoplankton
d) Because large sharks are zooplankton
Answer: b
Clarification: In aquatic food web large sharks which is a top predator remains in the top level in trophic level. The order of trophic level in aquatic food web is phytoplankton->zooplankton->filterers->predators->top predator.
11. Why detritivores are considered at the zero level in the food web?
a) Because it eats only producers
b) Because it eats only consumers
c) Because it eats producers as well as consumers
d) Because it do not eat producers as well as consumers
Answer: c
Clarification: Detritivores are heterotrophs that obtain their nutrition by feeding on decomposing plant and animals. Detritivores play an important role in all ecosystems by getting rid of decaying organic matter left behind by the organisms.
12. Why lions are apex predators in grassland ecosystem?
a) Because lion do not eat other organisms
b) Because no other animal hunt lion for food
c) Because lion is the king of the jungle
d) Because lion is a herbivore animal
Answer: b
Clarification: Lion is considered as top predators or apex predators in the grassland ecosystem, because no other organisms hunt or kill lion for food. Usually, lion comes under tertiary or quaternary trophic level based on the food web.
13. “Trees produce acorns which acts as food for many insects and mice” is an example of__________________
a) Food chain
b) Food cycle
c) Food web
d) Food rotation
Answer: c
Clarification: In the above example many mice and insects depend on acorns for food. Since many organisms depend on the particular organism or plant for food in order to get the energy they are known as food web.
14. Food webs are more stable than food chains.
a) True
b) False
Answer: a
Clarification: Food chain deals with one animal dependent on another. But in food web if one animal becomes extinct predators still have other sources of food. If they didn’t have this coping mechanism when one species went extinct everything that depends on it would die.