How Did Dinosaurs Get So Huge?

Part of why we’re so fascinated with extinct dinosaurs it’s just hard for us to believe that animals that huge actually existed. And yet, they existed! From the Jurassic to the Cretaceous Periods, creatures as tall as a five-story building were shaking the Earth.

Produced in collaboration with PBS Digital Studios:

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Female dragonflies fake sudden death to avoid male advances | New Scientist

You could almost say they are drop-dead gorgeous: when certain female dragonflies are pursued by unwanted suitors, they deter them by crashing to the ground

Source: Female dragonflies fake sudden death to avoid male advances | New Scientist

Secrets of the X chromosome – Robin Ball, TED-Ed

The sequence of DNA that we inherit from our parents encodes directions for making our cells and giving us specific traits. Identical twins have the same DNA sequence, so how can one twin end up with a genetic disorder while the other twin does not? Robin Ball explains how the secret lies in X chromosome inactivation.

Lesson by Robin Ball, animation by Anton Trofimov.

How menstruation works – Emma Bryce

At this moment, three hundred million women across the planet are experiencing the same thing: a period. The monthly menstrual cycle that gives rise to the period is a reality that most women on Earth will go through in their lives. But why is this cycle so universal? And what makes it a cycle in the first place? Emma Bryce gives a primer on periods.

Lesson by Emma Bryce, animation by Kozmonot Animation Studio.

How do pregnancy tests work?

Over-the-counter pregnancy tests give potentially life-changing results with a pretty high rate of accuracy. But how do they work? Tien Nguyen explains how each test performs a scientifically rigorous, multi-stage experiment that goes from start to finish in the time that it’ll take you to watch this video.

Lesson by Tien Nguyen, animation by Andrew Foerster.

Making a Baby With Three Parents – World Science Festival

This week, British legislators in the House of Commons voted to enact laws that would make the U.K. the first country to allow the in vitro fertilization technique known as mitochondrial transfer. Because the resulting offspring contains DNA from three separate people (two parents provide the nuclear DNA, which controls most of our personal traits, and a second woman provides mitochondrial DNA, which is thought to control basic cell functions), the technique is also referred to as “three-parent IVF,” a term almost as controversial (as journalist and physician Emily Senay points out in the video above) as the procedure itself.

In the clip from the 2014 World Science Festival program “Designer Genes: Fashioning Our Biological Future,” fertility specialists Paula Amato and Jamie Grifo discussed the science behind this technique.

Featured image credit: iStock / comugurhan

By: World Science Festival Staff

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via Making a Baby With Three Parents – World Science Festival.