Sigrid explains the religious significance of Easter and the various days of Lent. Why do people observe Good Friday, or celebrate Mardi Gras? Find out in this video.

Easter eggs are commonly associated with Easter. Let's have a look at why that is, and what traditions have emerged.

This segment looks at the advantages and disadvantages of swarm fish and loner fish, providing insight into their coloration and behavior. Spectacular footage reveals twobar sea bream, trumpet fish, barracudas, and harlequin sweetlips.

Green sea turtles (the largest hard-shelled sea turtle) and whale sharks (the largest shark and fish overall) are featured in this segment. We also encounter a langouste, otherwise known as a rock lobster, and a moray eel lurking in their coral reef habitat.

We learn about the thousands of kilometers that humpback whales travel from their summer habitat in the polar regions to the tropical or subtropical waters where they spend the winter. Their multi-versed songs and the markings on their flukes are also discussed.

Marine mammals are the focus of this segment on coastal sea life. Humpback whales mostly swim along the coasts, whether in the Northern or Southern Hemisphere. Seals are semi-aquatic and try to stay as close to the coast as possible, though they'll search for prey in depths of up to forty meters.

California sea lion communication, mating habits, and past and present threats to their survival are discussed. This segment additionally features amazing aerial photography of their rocky coastal habitats.

The video starts with information about coastal geology and the evolution of birds. It includes amazing footage of white storks, wildebeest, as well as zebras in East Africa's Serengeti region.

The focus of this segment is on animals of the African savanna. We get to see giraffes and elephants, the largest of the land creatures, as well as cheetahs, the fastest.

Rhinoceroses, or rhinos for short, are the largest land animals after elephants. Five species remain (two in Africa and three in Asia) and all are endangered as a consequence of the illicit trade of their horns. The importance of rivers is another focus of this segment.

Dolphins are one of the smartest animal species on Earth. In fact, their encephalization quotient (their brain size compared to the average for their body size) is second only to humans. But exactly how smart are they? This video shares some incredible facts about dolphins.

The series draws to a close with footage of apes, the most direct ancestors of humans. The narrator nicely sums up the meaning of evolution and man's place in nature.

One way to prepare for Halloween is to make a jack o' lantern. In this segment, Sigrid explains what a jack o' lantern is, and how kids and adults celebrate Halloween.

The pumpkin is ready to carve out. Sigrid explains that pumpkins are indeed an edible type of squash and not just for making into jack o' lanterns. In fact, one pumpkin can become both a pumpkin pie and a jack o' lantern.

Sigrid finishes carving her pumpkin and places the candle inside so we can see the final effect of the jack o' lantern. Happy Halloween!