terms
Is this symbiosis? A deer eats leaves from a bush. Explain.
No. This is herbivory, not a close, long-term relationship between two species.
Bees and flowers: what does each organism gain?
The bee gets nectar (food), and the flower gets pollinated, helping it reproduce.
A bird nests in a tree. Who benefits? Who is affected?
The bird benefits by getting shelter. The tree is generally unaffected.
Name two parasitic plants.
Any two of mistletoe, dodder, or witchweed
A butterfly drinks nectar from a flower while carrying pollen to another flower. Classify the relationship and explain why.
Mutualism. The butterfly gets nectar, and the flower is pollinated.
Why is competition not symbiosis?
Competition is not a close partnership where organisms live together. Both organisms are trying to use the same limited resource, and both may be negatively affected.
A fungus helps a plant absorb more water. What does the fungus receive?
The fungus receives sugars (glucose) made by the plant through photosynthesis.
Why doesn't an orchid harm the tree it grows on?
It only uses the tree for support and does not take water or nutrients from it.
Which part of the relationship is called the host?
The organism that the parasite lives on or in and from which it takes nutrients.
A woodpecker builds a nest inside a tree. The tree is not harmed. What type of symbiosis is this?
Commensalism. The bird benefits by getting shelter, while the tree is unaffected.
Which relationship is +/−? Give an example.
Parasitism. Example: mistletoe on an oak tree or dodder on a tomato plant.
Why is pollination considered mutualism instead of commensalism?
Both organisms benefit, the pollinator gets food, and the plant reproduces through pollination.
Give two examples of commensalism involving plants.
Examples include orchid & tree, moss & tree, Spanish moss & tree, bird nesting in a tree, or a vine using a tree for support.
Explain why mistletoe can be considered a parasite.
It absorbs water and minerals from the host tree, benefiting itself while harming the tree.
A parasitic vine loses its host plant because the host dies. What will most likely happen to the vine?
It will likely die or struggle to survive because it depends on the host for water and nutrients.
Explain the difference between an interaction and symbiosis.
An interaction is any relationship between organisms. Symbiosis is a close, long-term interaction between two different species.
A plant suddenly loses all of its mycorrhizal fungi. Predict one problem the plant might experience.
It may absorb less water and nutrients, grow more slowly, or be less able to survive drought.
Explain why moss is usually considered commensalism.
It uses the tree as support and does not take nutrients or significantly harm the tree.
Compare dodder and mistletoe. How are they similar? How are they different?
Both are parasitic plants that obtain nutrients from a host. Dodder is a vine that wraps around its host, while mistletoe grows attached to branches of trees or shrubs.
A scientist observes that after a wildfire, many beneficial underground fungi are destroyed. Predict one effect this could have on nearby plants.
Plants may absorb less water and fewer nutrients, causing slower growth or lower survival.
A scientist says, "Every organism living near another organism is in a symbiotic relationship." Explain why this statement is incorrect.
Living near another organism does not automatically mean symbiosis. Symbiosis requires a close, long-term relationship between two different species.
A flower stops producing nectar. Predict what will happen to its pollinators and to the flower's reproduction.
Pollinators may visit less often because there is no reward, so the flower may receive less pollination and produce fewer seeds.
A vine starts taking nutrients from the tree instead of just climbing it. Has the relationship changed? Explain.
Yes. It changes from commensalism to parasitism because the tree is now being harmed.
Why wouldn't a parasite want to kill its host immediately?
If the host dies too quickly, the parasite may lose its source of water, nutrients, or shelter.
A relationship begins with a vine using a tree only for support. Years later, the vine starts absorbing water and nutrients from the tree. How has the relationship changed?
It changed from commensalism to parasitism because the tree is now being harmed.