Self-study
On the plains where it lives, an individual zebra stands out because of its black-and-white stripes, which contrast with the green or brown of the surrounding vegetation. ███ ██████ ███ █ ████ ████████ ███ ███ █████ ████ ████ ████ ███ ███ ███████ ████████ ██ █████ ██████████ ████ ██████ █████ ███████ ████ ████ █████ █████████
"Surprising" Phenomenon
Why do zebras survive, even though one of their predators (lions) can see stripes clearly, and zebras have black-and-white stripes that contrast with the green/brown of surrounding vegetation?
Objective
The correct answer should suggest something about either zebras, lions, or the environment that could increase zebras’ survivability against lions.
5.
Which one of the following, ██ █████ ████ ██████████ ████████ ███ ███████ ██████ ██████
a
Because the vegetation ██ ███ ████ ██████ ███████ ████ █████ ██ █████ ██ ███ ██████ ███████ ████ ███ ██ ████ ████ ██████████ ████████ ███ █ ████ ███████ █████ ████ ██ ██████ █████████ ██ ███ ████████
This suggests zebras don’t have true camouflage. This doesn’t help explain why zebras can survive against lions. We still know zebras’ stripes stand out against the background.
b
Zebras are able ██ █████ ████ ███ ████████ ██ █████ ████ ███ ██ ███ ████████ ███████ ██ ███ █████ █████ ███ █████████ ██ █████ ███ ███ ██████ ██████ ███ █████ ████ ███ ████
This suggests zebras can identify which lions are preparing to hunt. But it doesn’t suggest zebras can escape from those lions or can somehow hide from those lions. We still know zebras’ stripes stand out against the background. How can they survive being preyed on by lions?
c
Lions that hunt ██████ ███ ██████████ ███████ ██ █ ███ ████ ██████ ██ ████ ███ █████ █████ ██ ███ ███████████ ██ ████ ██ ███ ███ ███████ ████ ████ ██ ███████ ███ █████ ███ █████ ██ ██ █████ ████ ██ ██████ █ ████████ ████ █████ ███ █████ ████ █ █████████ ██████ ██ ██████████ ██ ███ █████
This tells us a feature of lions that makes them better at hunting. But if we’re trying to explain how zebras survive, we want an answer that makes lions worse at hunting zebras.
d
When lions hunt, ███ █████ █████ ██████ ██ ███ ████ ████████ ████ █ ████ ██████ ██ ████████████ ███████ ████ ██ ███ ██ ███ ███████ ██████
This tells us what lions do with food after killing prey. But we want to know why zebras don’t become dead prey in the first place.
e
When zebras run ██ █ ██████ ██ ████ █████████ ██ ██ ████████ ██ ███████ ███ ██████ ████████ ████ ██ █████████ ███ █ ████████ ████████ █ ██████ ██████████ ██ ███████ ███ ████████
This tells us something about zebras’ stripes that can help them avoid being killed by predators. If the stripes can make it harder for a predator to see the outline of an individual zebra, that predator might have a more difficult time killing that zebra.