Direct relationship (between keystone species and other organisms):

Keystones species are very functional in the ecosystem in which there removal or absence as predators can lead to explosion of prey populations and decrease diversity. Keystone species help define an ecosystem and without they ecosystem can cease to exist.

Explanation:

Keystone species are predators species that help regulate the populations of other species through its activities or effects on the ecosystem. Keystone species exert both direct or indirect activities on the ecosystem. An indirect interaction occurs when species influence one another through their interactions with other species. Which can be inform of competition, interaction modifications e.t.c

there are 35 white marbles

step-by-step explanation:

y- yellow marbles

4y + 5 = 45

subtract 5 from both sides

4y = 40

divide for from both sides

y = 10

plug in 10 to get 40 yellow marbles then subtract by 5 to get 35 marbles

thus there are only 10 yellow marbles