Answer:
In uranium-lead dating, for instance, the radioactive decay of uranium into lead proceeds at a reliable rate. Based on the very old zircon rock from Australia we know that the Earth is at least 4.374 billion years old.
And that's how after rounding we know that earth is 4.5 years old.
<h3>Anthrax is an uncommon, but deadly, disease produced by Bacillus anthracis, a spore-forming bacterium.</h3>
<u>Explanation</u>
- Anthrax bacteria usually enter the body through a skin wound. You can have become infected if you intake tainted meat or inhale the spores.
- ID50, the number of microorganisms needed to create a demonstrable infection by 50 percent.
- The ID50 for cutaneous anthrax attributable to Bacillus anthracis is 10-50 endospores, while the ID50 for inhalation anthrax is 10,000 to 20,000 endospores.
- Ciprofloxacin is the alternative treatment for anthrax when mutated forms are identified. It is suggested for post- inhalation anthrax.
Answer:
In the last step of the scientific process when they compare their results.
Explanation:
The scientific process can be described of the following steps in order:
Starting with the observation, finding a point that asks a question which will be investigated, constructing a hypothesis that can be tested, testing the hypothesis and lastly comparing the results and starting over.
The example given in the question has a question to investigate, the students have a hypothesis. They test it and find out that the water sample can hold 20 amoeba which does not match their predictions. The students will check if their results match their predictions in the last step of the process when they compare their results with their hypothesis.
I hope this answer helps.
The cell membrane<span> is semipermeable, meaning that only certain molecules and </span>substances<span> can pass through </span><span>the cell membrane.;
Hope this helps :))</span>
