A species of kangaroo has a diploid chromosome number of 16. After meiosis, to develop the kangaroo’s sperm or egg, the haploid number would be . When fertilization occurs, the zygote would again have 16 chromosomes.

Just to prove that the persons answer on top of mine is correct :D

Explanation:

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates