In this episode of Tiny Show and Tell Us, we talk about what dark energy and dark matter are made out of and how knowing more could upend our understanding of the Big Bang. Then we cover microchimeric cells — cells transferred between baby and mom — and how new research in mice shows that fetal cells that took residency in mom from a first pregnancy are replaced by new fetal cells of a second pregnancy.

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A transcript and references for this episode can be found at acs.org/tinymatters.

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