Jaguars are a keystone species in the Amazon. Describe how they can be so essential to the ecosystem despite being significantly less abundant than many other species.

jaguars are keystone species because they feed herbivorous species that might decimate the plants of the ecosystem

Explanation:

Keynote species are species that help to maintain the homeostasis of the ecosystem so if they lack then the ecosystem would change drastically. Moreover, a top predator is a predator that occupies the highest trophic level in the food chain. Jaguars are both keystone species and top predators that feed herbivorous species, maintaining the health of the food chain by eliminating the excess of primary consumers that otherwise would feed too many plants (i.e., primary producers) which produce and store energy at the bottom of the food chain.

i took a test for bio that had this question and these were the correct answers, not sure if this is any now lol

the nervous system and the muscular system work together.  

sweat reaches the surface of the skin and evaporates into the air.

muscles underneath the skin relax, causing hair on the skin to lay flat.