Question

Plants and animals share a very long history of intimate relationships and have evolved in response to each other’s influence. Briefly describe three actual relationships or interactions between plants and non-human animals. One should be mutually beneficial to both species, one should benefit the plant at the expense of the animal, and one should benefit the animal at the expense of the plant. Be sure to include details of the relationship, including the names of the organisms and specific benefits or expenses involved.

Answer 1

Plants and non human animals in a community interact in many different ways. An interaction may benefit both individuals, or the interaction may benefit one organism at the expense of other.This include mutualism(both are benefited),Predation of plants by animals like herbivores and predation of insects by carnivorous plants .

1)Mutualism

The relationship which is mutually beneficial to both the species is Mutualism(+,+) .It is a type of interaction between two species which co-operates with each other and both of them get benefit.Mutualistic relationships can be thought as a biological barter system.
Some prominent examples are :
(1)Fig tree and pollinator wasp
Figs depend on wasps to make their seeds and distribute their pollen. In turn, the fig tree acts as a womb where the fig wasps can reproduce.When the female flowers inside the immature fruit are ready for pollination the fig emits an enticing aroma that attracts only female wasps of the specific type for that tree. The wasp finds the fig by its scent and struggles to get inside through the small opening at the end of the fig.While struggling they dust the pollen on their body and when they fly into another fig tree it dusts the pollen into it and thus acts as a pollinator for fig.The fig free inturn,helps wasp to reproduce.
(2)Ophyrus orchid and bumblebee
Orchids (genus Ophyrus) have a specialised petal labellum resembling a female bee and produce pheromones produced by female bee. When male bee finds it ,it attempts to mate with the flower ie.pseudocopulation hence while doing this the male bee recieves the pollinia.Due to this pollens can be transferred to other plant and inturn male bee attains a sexual pleasure or satisfaction.

2) Predation by carnivorous plants

The relationship in which plant is benifited at the expense of an animal is usually shown by insectivorous plants.This relation is a type of parastism where one organism is benifited and other damages .
Carnivorous plants, such as the Venus fly trap and the pitcher plant, consume insects. Considering the examples:
(1)Pitcher plants catch their prey in a pool of water containing digestive enzymes .The preys usually are insects that attract prey with nectar bribes secreted by the peristome and bright flower-like anthocyanin within the pitcher. The linings of pitcher plants are covered in a loose coating of waxy flakes that are slippery for insects, causing them to fall into the pitcher, hence the plant benifits and the insects are trapped and killed.
(2) Venus fly trap captures an insect between the two lobes of a leaf and seals the insect inside with digestive enzymes. These plants absorb nutrients from the insects as they become available during digestion.Hence at the expense of these insects,plants are benefited.

3) Predation by animals(Herbivory)

The relationship in which animal benifits at the expense of a plant is Herbivory. It is the act of eating plants by animals . Herbivory occurs above and below the ground. When animal eats the plant the animal is benifits while the plant is damaged.Considering some examples using feeding strategies like grazing and browsing.

(1)Grazing- Cattle , horses and sheep forage on grass as a part of animal husbandry.Sheep and goats were domesticated by nomads before first settlements were created,enabling cattle and pigs to be kept.Hence the animals derive it's food from plants while plants are damaged .

(2)Browsing- a herbivore like deer, goat feeds on leaves, soft shoots, or fruits of high-growing, generally woody plants such as shrubs and also herbaceous dicots.

In Herbivory type of interaction both the animals and plants have developed specialised features and feeding strategies for animals and protection for plants.