Sexual Reproduction - Chapter 3

Learn the key concepts in ecology and what makes populations change over time, with Professor Lindsay Turnbull from the University of Oxford Ecology is the study of plants and animals in their environments but what kinds of questions do ecologists try to answer? We begin with a population - a group of organisms belonging to the same species that live in one place. Some populations are stable, while others boom and bust, and we find out why births and deaths are key to understanding stability. We then consider why there are so many species on Earth and in doing so discover the ecological niche that constrains organisms to a specific role. Finally, we take a quick look at humans, who have broken out of their niche and taken control of the planet.

Plants are awesome, with photosynthesis being the most disruptive invention ever! Join Professor Lindsay Turnbull from the University of Oxford to understand why Plants don't have faces, so we don't know what they're thinking, and can even (horror!) write them off as boring. In this video, we examine the evolutionary history of the land plants: from an ancestral alga to the diversity of modern flowering plants that cover our planet today. We will see how plants stole the technology for photosynthesis - undoubtedly the most disruptive invention of all time - and how their activities changed the biosphere forever. Finally, we explore the range of features that allow a large tree in full leaf to suck up a tonne of water every day.

Take a guided tour of the biology and ancestry of the vertebrates with Professor Lindsay Turnbull from the University of Oxford Want to know more about the group of animals you belong to - the vertebrates - and how we are all descendants of a plucky fish that hauled itself onto land? In this video we discover the fishy ancestor of the vertebrates: a type of lobe-finned fish, which are extremely rare in today's oceans.

Take a whistle-stop tour of the Animal Kingdom with Professor Lindsay Turnbull from the University of Oxford Everyone can name a few animals - but did you know that most familiar animals only come from one group - and there's more than 30 to choose from?! In this video we discover the probable ancestor of the animals - a strange type of eukaryotic cell that fed on bacteria. But around 540 million years ago the animals experienced a burst of creativity, and a whole range of different animals sprang into being in the blink of a geological eye. We take a look at a few of the major groups - including arthropods, annelid worms and molluscs - which all play host to thousands of species.

Explore the mysterious origins of the cells all multicellular organisms are made from - eukaryotic cells - with Professor Lindsay Turnbull from the University of Oxford Everyone sometimes thinks they're special, but have you ever learned the truth of how special the cells in your body are? In this video we discover the 'ancient ones', a group of cells called the archaea, and the special role they play in the evolution of eukaryotes. Eukaryotic cells are generally large and full of internal structures, called organelles, one of which, the famous mitochondria, isn't quite what it seems. Finally, we look how slime moulds can gang up when conditions are right, giving us a glimpse of how true multicellularity evolved.