The third episode is devoted to the ways in which plants reproduce. Pollen and a stigma are the two components needed for fertilisation. Most plants carry both these within their flowers and rely on animals to transport the pollen from one to the stigma of another. To do this, they attract their couriers with colour, scent and nectar. It isn't just birds that help pollination: some mammals and reptiles also do so. However, it is mostly insects that are recruited to carry out the task. To ensure that pollen is not wasted by being delivered to the wrong flower, some species of plant have developed exclusive relationships with their visitors, and the gentian and its attendant carpenter bees is one example. Since pollen can be expensive to produce in terms of calories, some plants, such as orchids, ration it by means of pollinia and a strategically placed landing platform. Other orchids offer no reward for pollination, but instead mislead their guests by mimicking their markings and aroma, thus enticing males to 'mate' with them (Pseudocopulation). The most extreme fertilisation method is one of imprisonment, and one plant that uses it is the dead horse arum. It is often found near gull colonies, and mimics the appearance and smell of rotting flesh. Blow-flies are attracted to it, and are forced to stay the night before being allowed to depart in the morning, laden with pollen. Finally, Attenborough introduces the world's largest inflorescence: that of the titan arum.

In this mind-bending series, Professor Jim Al-Khalili explores the vast range of size in the universe, from tiny atoms to gigantic, interconnected galaxies.
In the first episode, Jim will enter the world of objects that are too tiny to glimpse with the naked eye. Starting with the smallest insects, he moves on to encounter living cells with amazing superpowers and confronts some of humanity's deadliest enemies in the form of viruses. Going smaller still, he encounters wondrous new nanomaterials such as graphene, discovered by physicist Andre Geim. These are revolutionising engineering, medicine, computing, electronics and environmental science. Finally, Jim comes face to face with the fundamental building blocks of the world around us – atoms – and reveals why understanding the science of the 'small' is crucial to the future of humanity.

The second episode is about how plants gain their sustenance. Sunlight is one of the essential requirements if a seed is to germinate, and Attenborough highlights the cheese plant as an example whose young shoots head for the nearest tree trunk and then climb to the top of the forest canopy, developing its leaves en route. Using sunshine, air, water and a few minerals, the leaves are, in effect, the "factories" that produce food. However, some, such as the begonia, can thrive without much light. To gain moisture, plants typically use their roots to probe underground. Trees pump water up pipes that run inside their trunks, and Attenborough observes that a sycamore can do this at the rate of 450 litres an hour — in total silence. Too much rainfall can clog up a leaf's pores, and many have specially designed 'gutters' to cope with it. However, their biggest threat is from animals, and some require extreme methods of defence, such as spines, camouflage, or poison. Some can move quickly to deter predators: the mimosa can fold its leaves instantly when touched, and the Venus flytrap eats insects by closing its leaves around its prey when triggered. Another carnivorous plant is the trumpet pitcher that snares insects when they fall into its tubular leaves. Attenborough visits Borneo to see the largest pitcher of them all, Nepenthes rajah, whose traps contain up to two litres of water and have been known to kill small rodents.

The fifth episode of the series is a fascinating exploration of the dinosaur era and its impact on the evolution of life on Earth. Through a journey of 200 million years, we discover how the breakup of Pangea and tectonic changes shaped biodiversity and created environments for dinosaurs and other forms of life to flourish. From the majestic Diplodocus to the formidable Allosaurus, the documentary brings to life the giants that once dominated our planet. Additionally, it shows the evolution of plants, highlighting the emergence of flowers and their symbiotic relationship with insects, such as termites and ants, whose social and evolutionary dynamics are explored in depth. The narrative also addresses the rise of mammals and their coexistence with dinosaurs, highlighting species such as the Numbat and their struggle for survival.
With stunning imagery and a captivating narrative, this episode is an invitation to learn, marvel, and reflect on the extraordinary history of life on Earth.

An alarming decline in insect populations could devastate all life on earth. What's causing it, and can anything be done to stop it?
Insects are disappearing across the world. If we lost our pollinators, we would lose 80 to 90% of the plants on the planet. That is not an option. It's the ecosystems on this planet that keep humans alive. Scientists warn us that the insect apocalypse is entirely possible.

Mammals from tiny shrews, giant anteaters, armoured armadillo to bats have specialised in eating insects. Some have evolved into complex and effective hunters, even pursued their prey into the skies