SciShow
Why Can't Hand Sanitizer Kill The 0.01% of Germs?
There's a scientific reason most hand sanitizers claim they can kill 99.99 percent of germs, and there's only one way to deal with the rest. Correction: there is a typo in the credits. This episode was written by Roshni Bhatt Hosted by:...
Bozeman Science
Environmental Matter Exchange
Paul Andersen explains how living organisms exchange matter with the environment. The importance of the surface area to volume ratio is emphasized using a simple mathematical model. The essential chemicals for life; water, carbon,...
SciShow
Do Plants Get Cancer?
Have you ever seen a tree with a big, twisted knot growing out of it? That's just one way that plants can show signs of cancer. Quick Questions explains.
Bozeman Science
Water Potential
Paul Andersen explains how populations experience exponential. He begins by address the major players; N (population size) and r (growth rate). He models population growth in rabbits through four generations. He then shows you how to use...
Crash Course
Medicinal Chemistry and Penicillin Total Synthesis: Crash Course Organic Chemistry
These days, we don't have to worry too much about meeting an early demise from ulcers, breaks in the stomach lining that could be fatal back in the early 1900s. This is because we have medicines to treat them, like proton pump...
Amoeba Sisters
Prokaryotic vs. Eukaryotic Cells (Updated)
This Amoeba Sisters video starts with providing examples of prokaryotes and eukaryotes before comparing and contrasting prokaryotic cells with eukaryotic cells! Contents: 00:00 Intro 1:27 Modern Cell Theory 1:37 3 Domains (with examples...
Amoeba Sisters
Osmosis and Water Potential (Updated)
Explore the process of osmosis in this updated Amoeba Sisters video! Video features real life examples of osmosis, important vocab, and introduces concept of water potential and turgor pressure in plant cells. Expand details for table of...
Bozeman Science
Mechanisms of Timing and Control
Paul Andersen explains how organisms regulate timing and control. Phototropism and Photoperiodism allow plants to respond to light throughout the day and year. Circadian rhythms are used in all organisms (including animals) as an...
Bozeman Science
Archaea
In this video Paul Andersen describes the defining characteristics of members in the domain archaebacteria. He starts with a brief description of the phylogeny of this group. He then describes the major characteristics on an archaea,...
Bozeman Science
Cell Division
Paul Andersen explains how cells duplicate through the process of cell division. Prokaryotic cells (like bacteria) duplicate through a process of binary fission. Eukaryotic cells (like you) duplicate body cells through mitosis and create...
Bozeman Science
Cell Membranes
Paul Andersen explains how cells are selectively permeable with the help of their cell membrane. The main constituents of the cell membrane, including cholesterol, glycolipids, glycoproteins, phospholipids, and proteins are included. The...
Bozeman Science
Bacteria
Paul Andersen describes the defining characteristics of the domain Eubacteria. He begins with a quick description of the phylogeny of bacteria and horizontal gene transfer. He then surveys the structures of a bacteria; nucleoid region,...
Bozeman Science
Plant Nutrition and Transport
Paul Andersen explains how nutrients and water are transported in plants. He begins with a brief discussion of what nutrients are required by plants and where they get them. He shows you dermal, vascular and ground tissue in monocot and...
Crash Course
The Sex Lives of Nonvascular Plants: Alternation of Generations - Crash Course Biology
Hank introduces us to nonvascular plants - liverworts, hornworts & mosses - which have bizarre features, kooky habits, and strange sex lives. Nonvascular plants inherited their reproductive cycle from algae, but have perfected it to the...
Crash Course
Plant Cells: Crash Course Biology
Hank describes why plants are so freaking amazing - discussing their evolution, and how their cells are both similar to & different from animal cells.
Curated Video
Passive Transport: Osmosis in Animal and Plant Cells
Osmosis is the movement of water across a semipermeable membrane from a region of lower solute concentration to higher concentration. Tonicity refers to how an extracellular solution affects a cell’s water content, described as...
Curated Video
Symplast Apoplast and Vacuolar Pathway
Plants absorb water from the soil using root hairs, and transport it through three main pathways: vacuolar, symplast, and apoplast. In the vacuolar pathway, water moves through vacuoles and plasmodesmata but faces high resistance. The...
Curated Video
Gram Staining
Gram staining is a differential staining method that classifies bacteria as Gram-positive (purple) or Gram-negative (red) based on their cell wall structure and composition. Gram-positive bacteria retain crystal violet due to a thick,...
Curated Video
Viruses vs Bacteria: What's the difference
Viruses and bacteria have their own set of characteristics that distinguish them. But what are those differences? Well, in this video, we will cover the main differences between those 2 groups of microbes.
Curated Video
Cell wall
A flexible or rigid boundary protecting a cell, outside the cell membrane. A Twig Science Glossary Film. Key scientific terms defined in just 60 seconds using stunning images and concise textual definitions. Twig Science Glossary Films...
Curated Video
Factpack: Scale of the Atom
How small is an atom? Comparing the size and number of atoms in tiny objects. Chemistry - Atoms And Bonding - Learning Points. A Twig FactPack Film. Open a discussion on what has been already learnt in a topic, or use to grab attention...
Curated Video
What is a Cell? - Life’s Building Blocks
Every living thing on our planet, from plants to animals, is made up of cells. Cells are the building blocks of life, but what are they and how do they work? Biology - Cells And DNA - Learning Points. All cells have vital genetic...
Curated Video
Osmosis and Volume
We look at the effects of osmosis on the volume of potato and the appearance of red onion cells. Two cylinders of potato are measured and weighed before one is placed in salt water and the other in fresh water. We can see how osmosis...
Curated Video
Agar Cube Diffusion
We use coloured agar cubes to see how different shapes change the rate of diffusion. The cubes are made using sodium hydroxide and phenolphthalein indicator to give them a pink colour. When these are added to hydrochloric acid, the...