Why do biological classification keys always present only two choice at each step? btw i am doing a shark dichotomous key analysis

Because it is simple, and more capable way of separating organisms.

Explanation:

A biological key is also known as dichotomous key or identification key, which helps to classify the organisms by giving classifier two options in each stage until the identification occurs.

The biological classification key always present only two choices at each step, because it is simple and more capable way of separating organisms without confusion. Dichotomous means breaks into two parts and that's why dichotomous always gives two choices at each stage. In each step, the user is represent with the two statements based on the characteristics of the organisms.

1.  6,000,000, 000,000,000,000,000,000 (6 x 1024) kilograms.

2. 92,955,828 miles

3. a region of space having a gravitational field so intense that no matter or radiation can escape.

4. Flies need sticky feet to walk on ceilings, but not so sticky that they get stuck upside down. So each foot comes with a pair of claws that help hoist the gooey foot off the wall. Flies use several different techniques to get unstuck: pushing, twisting, and peeling its footpads free.

5. No

6. In Your Dreams. This hypothesis defines dreaming as a way to act out unconscious desires in a safe or “unreal” setting, presumably because to do so in reality would be unacceptable or even detrimental. But even in the 21st century we still are not sure why we dream. The only way to study dreams is to ask the dreamer.

7. Ocean water is salty because it contains high concentrations of dissolved minerals known collectively as salts. Around 3.5% of ocean water is comprised of salts, depending on where in the world one is; equatorial waters tend to be saltier, while northern waters are slowly becoming more fresh. Aug 5 2019Ocean water is salty because it contains high concentrations of dissolved minerals known collectively as salts. Around 3.5% of ocean water is comprised of salts, depending on where in the world one is; equatorial waters tend to be saltier, while northern waters are slowly becoming more fresh. Aug 5 2019

8. Earthquakes generate three types of seismic waves: P (primary) waves, S (secondary) waves and surface waves, which arrive at seismic recording stations one after another.

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