Explanation:
under what circumstance does a negative cell presents An antigen to another negative cell
Atomic number shows the number of protons in the nucleus of an atom.
Atomic weight shows the is an another term for atomic mass, which means <span>It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.</span>
The expected phenotypic ratio for a cross between two individuals that are heterozygous for a given trait is 3:1.
<h3>What is Phenotype?</h3>
This is referred to the physical characteristics of an organism such as the size, shape etc.
When two heterozygous traits are crossed:
Rr × Rr ⇒ RR Rr Rr rr
The ratio is therefore 3:1 of the dominant to recessive phenotype.
Read more about Phenotype here brainly.com/question/22117
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