An isotope of any element is the same, with a variation in the neutrons of the nucleus.
The mass number change but the atomic number doesn't.
In this case, protium, deuterium, and tritium are all hydrogen isotopes.
Protium is 1H or Hydrogen-1 is without neutrons.
Deuterium is 2H or Hydrogen-2 has one neutron.
Tritium is 3H or Hydrogen-3 has two neutrons.
I think the answer is B,A,E
Darwin's plans to find out about simulated choice by examining pigeons is that he needed to learn whether you can change the entire species taking after that particular pigeon into another type of pigeons. I hope the answer will help you.
That would be B. Cell Wall
Hope this helps.
Nucleoid is the answer
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