the egg after fertilization and before it has developed into a recognizable form.

An ultrasound showing a blurry image of a fetus.

How Fast Do Embryos Grow?

Megha Pillai Logan Hunt

We start off as a single tiny cell, and yet somehow we are born as whole humans. Get to know the stages of that process and how quickly we develop.

Three mice on a blue blanket. The mouse on the right has one red eye and one black eye, showing that it is a chimera.

Creating Chimeras

Tazeen Ulhaque

Most organisms have just one set of DNA. So why would some scientists want to work with or create organisms that have two sets of DNA?

A picture of two young twin girls smiling.

Twin Tales

Tazeen Ulhaque Whitney Alexandra Tuoti

Have you ever wondered why some twins look so alike and other siblings may not? Let’s explore how twins form in the womb and how they may grow up to be similar or different.

Confronting Human Chimerism

Tazeen Ulhaque

Most people have just one set of DNA throughout their body. But what happens to humans who are born with two sets?

An illustration of a female reproductive system with a ruptured fallopian tube with red blood drops coming out of it

Ectopic Pregnancy: An Unexpected Path

Logan Hunt

Pregnancy isn’t perfect, and many things can go wrong. What happens when a growing embryo is in the wrong part of the pregnant person's body?

A small T shaped piece of plastic resting in an open palm

Introducing the IUD

Molly Jacobson

Doctors place Intrauterine Devices (IUD) in the bodies of some females to help prevent pregnancy. Learn about how these devices work and how long they’ve been around.

A scientist wearing thick blue gloves uses tongs to dip test tubes into a bath of liquid nitrogen. Steam rises from the cold-looking liquid.

Cells, Frozen in Time

Risa Aria Schnebly

If a living organism freezes, it can die. But by freezing living cells at just the right temperature, scientists can preserve living cells instead of killing them.

Xs and Ys: How Our Sex Is Decided

Risa Aria Schnebly

Our biological sex determines a lot about the way our bodies look and function. But what determines our biological sex?

Focusing on Female Infertility

Emily Santora

What happens when a person wants to have a baby, but after years of trying, it just doesn’t happen? A lot of people want to become pregnant, but let’s learn about what may prevent pregnancy.

Someone raising their arm to show off armpit hair

Helpful Sex Hormones

Risa Aria Schnebly

Our biological sex is mainly controlled by our sex chromosomes. But sex hormones also influence what body parts and characteristics we have.

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