Questions on Symbiosis (Ecological Relations)
Multiple-Choice Questions: Symbiosis in Ecological Relations
1. What is symbiosis in ecology?
A) Interaction where one species is harmed
B) Interaction between two different species living closely together
C) One species feeding on another
D) Species competing for resources
E) Species living independently
2. Which of the following is a mutualistic relationship?
A) A tick feeding on a deer
B) Bees pollinating flowers while getting nectar
C) A predator hunting prey
D) A parasite living inside a host
E) Two species competing for food
3. What type of symbiosis harms one species and benefits the other?
A) Mutualism
B) Commensalism
C) Parasitism
D) Competition
E) Predation
4. In which type of symbiosis does one species benefit and the other is neither helped nor harmed?
A) Parasitism
B) Mutualism
C) Commensalism
D) Competition
E) Predation
5. Which of the following is an example of commensalism?
A) Barnacles growing on a whale’s skin
B) Mosquitoes feeding on blood
C) Clownfish and sea anemones
D) Wolves hunting deer
E) Ants farming aphids
6. Which symbiotic relationship best describes lichen?
A) Parasitism
B) Commensalism
C) Mutualism
D) Competition
E) Predation
7. What is an example of a parasitic relationship?
A) Bees and flowers
B) Fleas living on dogs
C) Oxpeckers eating ticks off buffalo
D) Mycorrhizae and plant roots
E) Cleaner fish and larger fish
8. Which symbiotic relationship benefits both species involved?
A) Parasitism
B) Competition
C) Mutualism
D) Commensalism
E) Predation
9. What role do mycorrhizal fungi play in symbiosis with plants?
A) They harm the plants by eating roots
B) They help plants absorb nutrients in exchange for sugars
C) They compete with plants for water
D) They feed on dead organic matter only
E) They act as predators
10. In which symbiotic relationship do both partners depend so closely that they cannot survive without each other?
A) Mutualism
B) Facultative mutualism
C) Parasitism
D) Commensalism
E) Competition
11. What term describes symbiosis where one species lives inside another, often causing harm?
A) Endosymbiosis
B) Exosymbiosis
C) Mutualism
D) Commensalism
E) Competition
12. Which of the following is an example of facultative mutualism?
A) Oxpeckers cleaning ticks off buffalo, but both can survive separately
B) Lichens, which cannot survive without each other
C) Tapeworms living in intestines of hosts
D) Mosquitoes feeding on blood
E) Barnacles on whales
13. Which symbiotic relationship involves species that live physically close but do not benefit each other?
A) Parasitism
B) Commensalism
C) Neutralism
D) Mutualism
E) Competition
14. How do cleaner fish contribute to symbiotic relationships on coral reefs?
A) They clean parasites off larger fish, benefiting both
B) They feed on coral polyps
C) They eat other small fish aggressively
D) They compete with coral for space
E) They prey on algae
15. What is a key characteristic of obligate mutualism?
A) Both species benefit but can live independently
B) One species benefits and the other is harmed
C) Both species cannot survive without each other
D) One species benefits, the other is unaffected
E) Neither species benefits
16. Which of these pairs is an example of mutualism?
A) Cuckoo bird and host bird
B) Bees and flowering plants
C) Leeches and mammals
D) Barnacles and whales
E) Parasites and hosts
17. What is endosymbiosis?
A) One species living on the surface of another
B) One species living inside another
C) Two species competing for food
D) Mutual benefit with no physical contact
E) Predation
18. Which of the following symbiotic relationships is beneficial to one and neutral to the other?
A) Mutualism
B) Parasitism
C) Commensalism
D) Competition
E) Predation
19. What type of symbiotic relationship do nitrogen-fixing bacteria and leguminous plants have?
A) Parasitism
B) Competition
C) Mutualism
D) Commensalism
E) Predation
20. Which of the following is NOT a type of symbiotic relationship?
A) Mutualism
B) Parasitism
C) Competition
D) Commensalism
E) Predation
- Questions on Aquatic Organisms (Ecology)
- Questions on Predation (Ecological Relations)
- Questions on Competition (Ecological Relations)
Answer Key with Explanations
1. B – Symbiosis is a close interaction between different species living together.
2. B – Bees and flowers both benefit; bees get nectar and flowers get pollinated.
3. C – Parasitism benefits one species but harms the other.
4. C – Commensalism benefits one species and the other is unaffected.
5. A – Barnacles benefit by attaching to whales; whales are neither helped nor harmed.
6. C – Lichen is a mutualistic relationship between fungi and algae/cyanobacteria.
7. B – Fleas feed on dogs and harm them; this is parasitism.
8. C – Mutualism benefits both species involved.
9. B – Mycorrhizal fungi help plants absorb nutrients and get sugars in return.
10. A – Obligate mutualism requires both species to survive.
11. A – Endosymbiosis is when one species lives inside another.
12. A – Facultative mutualism means both species benefit but can survive independently.
13. C – Neutralism is close living without benefit or harm.
14. A – Cleaner fish remove parasites, benefiting both themselves and larger fish.
15. C – Obligate mutualism requires both partners for survival.
16. B – Bees and flowering plants have a classic mutualistic relationship.
17. B – Endosymbiosis involves one species living inside another.
18. C – Commensalism benefits one species with no effect on the other.
19. C – Nitrogen-fixing bacteria and legumes have a mutualistic relationship.
20. C – Competition is not considered a symbiotic relationship
Dive into the groundbreaking science of neurotransmitters—your brain’s invisible architects—in Chemical Harmony: How Neurotransmitters Shape Our Lives (2025). This meticulously researched book reveals how serotonin, dopamine, GABA, and other brain chemicals silently orchestrate every aspect of your existence, from decision-making and relationships to mental health and emotional resilience.Click here to buy
👉 +3000 Biology Questions with Answers Key.
Share Online!
