Brian Cox explains the origin of the mitochondrial symbiotic relationship with the cell. He starts with introducing the nucleus and gives context to the early cell types - prokaryotes and eukaryotes. Brian then explains what scientists believe was the beginning of a symbiotic relationship where a bacteria enters an archaea.
Louis Pasteur is remembered for his remarkable breakthroughs in the causes and preventions of diseases. This clip shows his successful vaccination of animals and his interest in replicating it for humans.
Old Major, a prize-winning boar, gathers the animals of the Manor Farm for a meeting in the big barn. He tells them of a dream he has had in which all animals live together with no human beings to oppress or control them.
This clip explains that, while the population of the Earth has dramatically increased in the last 100 years, the needs of humans are significantly less than the needs of animals in order for humans to eat them.