Tutor profile: Emily D.
Subject: Environmental Science
What is one event on the geologic timescale that impact humans today? Explain how.
(Many answers possible) One event on the geologic timescale that impact humans today is the Great Oxidation Event that dramatically increased the amount of oxygen (O2) in Earth's atmosphere. This caused a mass extinction, but also paved the way for the evolution of eukaryotic cells. This atmospheric change and the following evolution of eukaryotic cells created the necessary conditions for humans to evolve billions of years later.
What is one way that a keystone species might help hold the structure of an ecological community together?
Keystone species play a disproportionate role in influencing the structure of a community. One way they might do this is through a top-down pressure on the food web, keeping species at lower trophic levels in a specific balance by predating on them. Without this pressure, these species might dramatically increase their population sizes, impacting the rest of the community.
On Planet Slorp, an alien can eat an elephant in 4 hours. On Planet Beeboo, an alien can eat an elephant in 6 hours. If one alien from Planet Slorp and one alien from Planet Beeboo joined forces, how many elephants could the two aliens eat in one day?
First, we want to identify what we are looking for. We need to find out how many elephants will be eaten by the two aliens after one day, or 24 hours. Because they are working together, this will be a sum. # of elephants eaten by Slorp alien + # of elephants eaten by Beeboo alien We can find the number of elephants eaten by the Slorp alien by multiplying the RATE of eating times the TIME of eating. # of elephants eaten by Slorp alien = 1 elephant/4 hours * 24 hours = 6 elephants If we do the same for the Beeboo alien, we find that it can eat 4 elephants. If we add these together, we find that the two aliens can eat 10 elephants in one day.
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