1. SYMBIOTIC RELATIONSHIPS

2. The Monarch butterfly feeds as a larva on species of milkweeds. The milkweeds contain a group of chemicals called cardiac glycosides. Cardiac glycosides are poisonous to vertebrates. The larvae store these cardiac glycosides and the later adult Monarch butterfly contains them as well. If a bird (or other vertebrate such as a mouse or frog) eats a Monarch it finds them distasteful to begin with and is later sick.

4. Hookworms attach to the intestinal walls of humans and get nutrients from the host’s blood and tissue juices. Infected human experience digestive disorders and anemia.

6. Fungal hyphae live on the roots of plants. The fungal hyphae improve the nutrient uptake of the roots, protect the plants from pathogens, and produce plant growth hormone. The fungi get carbohydrates from the plant.

8. A lamprey eel fastens itself to a host fish, such as lake perch, and feeds on it. When the fish dies, the lamprey finds another host.

10. Burdocks, common weeds found along roadsides and in empty lots and fields have seed heads (burs) of burdocks long spines with hooked tips. The hooked tips catch onto the hair of passing vertebrates (cows, deer, dogs, humans) and the burs are carried elsewhere until they finally drop off or are pulled off by the carriers. The seeds are then dispersed to new locations.

12. Yucca moths lay their eggs in the seed pods of yucca plants. Larvae that hatch from the yucca moths’ eggs feed on some, but not all, the seeds. The plant is pollinated by the moth by carrying pollen from one yucca plant to another.

14. Orchid vines grow up the trunks of trees. The areas at the tops of the trees have more light than the areas underneath the trees. The orchid does not interfere with the sunlight received by the tree.

16. Ticks are arachnids which attach themselves to mammals, such as deer, dogs, and rabbits. They suck the blood of these mammals as a food source and can transmit diseases to the host.

18. Fire ants live with aphids, a type of plant lice. The fire ants eat a substance the aphids secrete and the aphids are protected by the fire ants from predators.