Year 12 Genetics and Evolution

Reminder: There are three key areas to this topic:

• The source of variation, including meiosis and mutations
• Dihybrid crosses and the inheritance of two traits at once
• Population genetics

 One of the best animations of meiosis I’ve seen!
Here is an extended version (with no narration) placing meiosis in the context of sexual reproduction. (It has a fantastic sequence on fertilisation and mitosis, although takes some artistic licence...)

Another great meiosis clip which covers how it results in variation too.

MEIOSIS AND MUTATIONS

• Stages of meiosis - Beautifully coloured animation with a quiz.
• Meiosis - Nice animation with stage names and controllable slider. Step-through or narrated.
• Mitosis and Meiosis Comparison 1 and Comparison 2 - Animation is the same for both, but quiz differs.
• BBC Biology: Meiosis - Revision bite on meiosis, including a step-through animation and a video which clearly shows crossing over. Test at the end.
• Special features of meiosis - Shows crossing over in closer detail as well as highlights the reduction division
• Crossing over interactive - Click through the stages to see how crossing over creates new combination of alleles (using colours, rather than letters, to represent alleles)
• Crossing Over Causes Genetic Variation - Simple animation showing how crossing over reshuffles alleles and results in unique gametes.
• Meiosis tutorial - Tutorial, diagrams, text, animations, quiz. Pretty long, I guess.
• Independent assortment - The importance of independent assortment in bringing about variation. Animation and text.
• Random orientation of chromosomes during meiosis - Another animation of independent assortment. A pretty one.
• Independent assortment and gamete diversity - An animated and narrated or step-through tutorial and a quiz. Good coverage.
• Independent Assortment Causes Genetic Variation - Simple animations to show how different assortments in each meiotic division of identical cells by meiosis can result in different sets of chromosomes in gametes.
• Evolution 101: Genetic variation - Click through the pages to review how variation comes about, including through mutations and meiosis.
• Genetics and adaptations - Mutations - Includes gene mutations,chromosome mutations, non-disjunction mutations, mutagens and polyploidy. Step-through interactives to help show you the different types.Too much depth for 2011’s Year 12, but still worth bearing in mind.

GENETICS CROSSES

• BBC Science: What is inheritance? - The revision bite that reminds you about inheritance and genetics, from inherited characteristics, through monohybrid crosses and the difference between expected and actual results to sex determination. Of course, there is a test bite at the end.
• BBC Biology: The dihybrid cross - The all-important dihybrid cross. One page overview, then a challenging test.
• Virtual Mouse – genetics - Time limited gizmo (5 minutes?) so work fast! Leads you through the thinking behind inheritance and alleles using a coin-toss model, how genotypes affect phenotypes, and you actually get to breed virtual mice! Also does dihybrid crosses using an online simulator.
• Drag-and-drop genetics cross practice problems - Practise a genetic cross on this interactive webpage. Just stick with this on page, then try the practice problems 1, 2 and 4 on this site.
• Genetics Practice Problems - An excellent way to check if you really know how to do those crosses. Do Monohybrid, Test cross and Dihybrid cross only. The rest can wait till next year.
• Mendelian genetics at The Biology Project - Monohybrid crosses, dihybrid crosses, and sex-linked inheritance. Do these when you are well and truly confident. You need to do your working on a separate sheet of paper.
• Dihybrid inheritance - How independent assortment results in 4 different phenotypes when looking at the inheritances of two traits at once. Uses round/wrinkled yellow/green peas. Interactive.
• Pedigree Problems - Notes on how to spot dominant or recessive conditions, (and whether something is X-linked or not). Not great, but there’s not a lot out there!

EVOLUTION & NATURAL SELECTION

• Genetic drift - Animated tutorial and quiz about drift in plants.
• Natural selection - Animated tutorial and quiz about selection of Darwin’s finches.
• Gene flow - Shows how migration can introduce new alleles to a population.
• Natural selection - Step-through or narrated animation of natural selection of butterflies includng (Batesian mimicry and) stabilising, directional and disruptive selection.
• BBC Science: Survival of the fittest - Evidence for and mechanisms of evolution.
• BBC Biology: Natural selection & speciation - Superb resource for this often difficult topic, including some thoughtful and highly relevant questions and answers. Supported by built-in video clips. (Speciation not needed at Y12 in 2011)
• Nowhere to Hide - Simple interactive where bugs come in two colours: green and orange, and get eaten by birds. You can change the colour of the background and see how that affects the proportion of the population that is each colour of bug
• Evolution in action - Interactive: Change the colour of the background and see what happens to a population of….things. Can keep going with this for ages. Experiment with rapid changes and slow changes to the background colour.
• Peppered moth simulation - Peppered moth simulation with a bluejay. Simulates lichen forest and sooty forest with stationary and moving moths. Can you, as the bluejay, find enough moth to not starve?
• Evolution 101: Natural selection - Click through the pages to review natural selection including how it leads to adaptation and clarifying misconceptions.
• Evolution 101: Genetic drift – Good notes and a model of sampling showing how drift can quickly result in the loss of variation from a population. Some mention of bottleneck and founder effect also.
• Mechanisms of Evolution - A maybe not so good animation depicting the effects of genetic drift, gene flow, mutations, non-random mating, and natural selection on allele frequences in a fish population.
• Founder effect or bottleneck? - Weird animation. The text and narration describe a bottleneck, but the animation is definitely showing founder effect.
• Simulation of genetic drift - What it says. Shows how alleles can be lost or fixed in small populations, but tend not to fluctuate so wildly in large ones. Comes with a short quiz to check understanding.

Year 12 Cell structures and their functions

The inner life of the cell - A BioVisions animation

HOW BIG IS A CELL?

• Cell size and scale  as compared to a rice grain. Quick flash animation.
• Compare sizes of cells - different types of cells are different sizes. Watch the animation.

DIAGRAMS ETC. FOR LEARNING THE FUNCTIONS OF ORGANELLES

• CellCraft! - Takes 2-3 hours, so not great for right before exams, but as far as I can tell, the people who played it learned quite a bit from it. During the game, there are opportunities for you to actually stop playing and read and learn more about the organelles involved. (If this link doesn't work, then google CellCraft Game and find one that does.)
• Inside a cell - 3D animal and plant cell structure. Click on parts to learn functions.
• Eukaryotic cell tour - A narrated collection of tutorials on the structures and functions in a cell. Click on the parts to learn more.
• Plant cell structure - Nice colourful 3D diagram (the likes of which you could never draw and probably won’t see in an exam) and descriptions of what each organelle does.
• Animal cell structure - Nice colourful 3D diagram (the likes of which you could never draw and probably won’t see in an exam) and descriptions of what each organelle does.
• Practice exercises - Images to click on and match to terms and statements describing structure and function of plant and animal cells.
• The Cell - Includes animations of what ribosomes, Golgi bodies, mitochondria etc do. Golgi is good; others a bit too complex.
• S-cool Organelles Including ER, Golgi, mitochondria and chloroplasts
• ER and golgi body - Animation of what the Golgi does 
• Lysosomes - A narrated animation that shows the formation and action of lysosomes brilliantly
• Mix’n’match: Animal cell  - Takes 2 minutes. 
• Mix’n’match: Plant cell - Takes 2 minutes. 
• Evolution of cell organelles - Extra for experts. How did cells with organelles evolve? Some ideas

CELL MEMBRANES

Cell membrane rap - Mr W summarises cell membrane structure and function in his own unique way.
There's a link to an interactive quiz that will come up as the credits are rolling - give it a go. 

• S-cool The cell membrane Brief coverage of structure and function. 
• Cell membrane - Explains the phospholipid bilayer structure in depth: what phospholipids are, what cholesterol does for a membrane, how proteins embed in the membrane etc. Shows the molecular structure of relevant molecules and explains how they associate with each other and water. Pretty complex.

TRANSPORT OF SUBSTANCES INTO AND OUT OF CELLS

 

Crash Course Biology: Membranes and transport

Covers most of the processes and has some analogies and animations. Thanks Hank!

• Cellular transport - Pretty decent overview. Covers cell membrane structure, passive transport (diffusion, osmosis) and active transport.
• Membrane transport - Pretty decent overview. Covers cell membrane structure, passive transport (diffusion, facilitated diffusion, osmosis) and active transport (ion pumps, cotransport, endocytosis) 
• Passive transport - Simple and facilitated diffusion, animated and narrated if you want.
• BBC Biology:Investigating cells: Cells and diffusion - Cell structure, diffusion and osmosis. 
• S-cool Movement - Diffusion, osmosis, facilitated diffusion, active transport.  
• How diffusion works - Narrated animation and a short quiz 
• How facilitated diffusion works - Narrated animation and a short quiz.
• How osmosis works - Narrated animation and a short quiz.
• Osmosis in eggs - The Sci Guys explain something you could do at home to observe osmosis in eggs. Photograph or film your results! Two aspects of the science involved are explained; obviously, the part about osmosis is what's important for you. 
• Osmosis rap - Mr W aces it again! Remember to try the interactive quiz linked to in the credits. 
• Active transport - Detailed examples used to explain principles of primary (Na+ / K+ pump) and secondary active transport at a membrane level
• Vesicle budding and fusing - Animation (narrated or step-through) and text.
• Endocytosis and exocytosis - A flash animation.
• Phagocytosis- Detailed animation.
• Protein secretion - An animation of secretion starting with protein manufacture in the rough ER through modification in the Golgi body and eventually secretion by exocytosis. The narration is overly complex, but the animation is worth a look to show what a series of diagrams in a book can never show.
• Transport videos - Quite a few videos (of real cells!) and explanations of transport processes, especially related to osmosis, in both plant and animal cells. 

ENZYMES

Mr W's enzymes song - Something something something something something something something enzymes...covers structure, function, and how enzymes are affected by pH and temperature.
Remember to take the interactive quiz at the end!

• BBC Biology:Investigating cells: Enzymes and aerobic respiration - The function of enzymes, factors affecting enzymes, and aerobic respiration. Sample questions and answers with hints too!
• How enzymes work - Narrated animation and a quiz. 
• How factors affect the function of enzymes - A video that covers the explanation of how temperature, pH and substrate concentration affect enzyme function, including how to interpret and explain graphs of enzyme activity. 'See more' to see the narration from the video in the description.
  Note: the "rate of the reaction" increases because the activity of the enzyme itself is increasing. 
• Heat changes protein structure: denaturation of an egg - Animation and text
• S-cool Enzymes - Revise then test yourself on how enzymes work and some of the factors that affect their function.
• Catalysis - See animations comparing a reaction with and without and enzyme, and also with inhibitors present.
• Enzymes and their uses - Text resource with a few diagrams and animations about enzymes. Not very interactive! Includes: Enzymes; Types of enzymes; Enzymes in digestion; The properties of enzymes; How do enzymes work?; Effect of temperature and pH; Uses of enzymes; Immobilised enzymes

PHOTOSYNTHESIS

•  S-cool Photosynthesis - Study some notes with simple colour diagrams then try some test questions.

RESPIRATION

• S-cool Respiration - Study some notes with simple colour diagrams then try some test questions. Goes a bit off topic when not focussing on cells though.
• BBC Biology: Investigating cells: Enzymes and aerobic respiration - The function of enzymes, factors affecting enzymes, and aerobic respiration. Sample questions and answers with hints too!

THE STRUCTURE OF DNA AND DNA REPLICATION

Crash Course Biology: DNA structure & Replication
Don't worry about the detail. Focus on how each original strand acts as a template for their complementary strands to be made, and recognise that several enzymes are involved in carrying it out (and therefore any factors affecting enzymes could affect the rate of DNA replication!).

• DNA, Fantastic! - Mr W's DNA rap. He covers the structure, using lots of suitable terminology, and one example of a point mutation that's useful for the gene expression topic later on.
• Genes and Inheritance  - A fairly comprehensive review of Year 11 Genetics. Mouseover specific terms to be reminded of definitions. Each page has a quiz at the end to check your understanding. Some interesting applications of inheritance with respect to genetically inherited diseases. A complete quiz at the end.
• Tour of the basics of genetics - Animations to remind you of the structure of DNA and how it works.
• Structure of DNA  - A narrated video to watch. Nice because it shows how the actual atoms in the molecule are arranged. Very complex in the vocab, so at best, just watch the pictures.
• DNA workshop: DNA replication (& protein synthesis) - Interactive animations to review the processes of DNA replication (and protein synthesis). Get involved; it doesn’t take long!
• DNA replication – This animation includes more of the nitty gritty of replication, showing the enzymes that are involved. e.g. helicase, polymerases, ligase.

HOW SCIENTISTS MADE THEIR DISCOVERIES ABOUT DNA

This isn't examined at any level, but it's still interesting!

DNA - The secret of life  How the structure of DNA was discovered, including the people involved,
and some of the controversies. Part 1 of a 5-part PBS documentary. 

• Meselson-Stahl experiment: DNA replication - How scientists found out that DNA replicates by unzipping and copying complementary strands.
• Decoding DNA - The science involved in decoding DNA – finding the sequence. More for 13BIO, but interesting nevertheless.
• DNA from the beginning - A huuuuuuge resource including text, animations, and a lot of the science behind the knowledge. Use the menus down the side to navigate through some of the main points of the genetics topic. Of the three main sections, Classical Genetics and Molecules of Genetics are the most relevant.

MITOSIS
Don't worry about the names of stages, just watch what the chromosomes are doing.

Here's a clip of mitosis in 3 dimensions. The narration is complex but the animation is good.

Cell Cycle and Mitosis [3D Animation]

This one does a good job of putting mitosis in the context of a whole cell cycle, and also gives some factors which affect whether a cell completes mitosis or not. 

Mitosis - ndsuvirtualcell

The quality of videos available on the net has improved so mCell Cycle and Mitosisuch lately. I'm  not sure which one is best to post!

Crash Course Biology: Mitosis
Again, the names of the stages aren't required, but watch the chromosomes, and recognise when, in a cell's life, mitosis occurs, and that it will involve LOTS of enzymes and energy (so will be affected by factors affecting enzymes or respiration).

• Mitosis -Narrated and/or step-through animation of mitosis with a quiz at the end.
• Cells Alive - mitosis - Compare a diagram of mitosis with photographs of an actual real cell dividing.
• Mitosis and the cell cycle - Narrated animation and a quiz. Animation is nice but the text level is high.
• Mitosis and cytokinesis - Narrated animation and a quiz. Animation is nice but the text level is high.
• BBC Science: Cell division - Cell division by mitosis, including stages, and then a test.
• Mitosis: Interactive Java Tutorial - Very detailed description of mitosis, and an animation to boot. Not particularly interactive.
• Genetics Review: Mitosis - Brief diagram and text reminder of the names of the stages of mitosis for Year 13.
• Mitosis and cytokinesis - Animation of these processes in a plant cell. High level text. 
• Cell division and cancer - Extra for experts. A somewhat long but good review of cell structure including specialisation, as well as cell division by mitosis (with an animation; no stage names). Includes what happens when cell division goes out of control i.e. cancer. Self-check tests throughout. 

Year 11 Acids and Bases

ATOMS, IONS, FORMULAE AND BALANCED EQUATIONS

K Science - Animations - Build your own atoms and ions by dragging the subatomic particles into place.

Ionic compounds (BBC Bitesize) - Review the theory behind the formation of ions, and ionic bonding. Has animations. Pages 1-4 are most relevant.
There's a link to a short interactive video too (see Activity at the top right). The video explains electron shells and how they relate to the periodic table.

Writing Ionic Formulas: Introduction - An 11-minute video that explains how to write formulae for ionic compounds.

 Writing Formulas with Polyatomic ions - Another 11 minute video. While not all the ions are ones you need, the principles are the same. 

Balancing equations - Gives you equations and the boxes in which to type numbers to balance them. You've got a minute to do each one, and if you make mistakes, a chance to change them. The equations themselves are not all relevant to this topic, but the skill certainly is! Practise it until you don't make mistakes. 

RATES OF REACTION

How to speed up chemical reactions (and get a date) - an analogy for the particle collision theory of rates of reaction. Covers the ways in which the rate of chemical reactions can be increased: increasing concentration, increasing temperature, increasing surface area, and catalysts. 

Crash course in Biology

I have recently been recommended Hank Green's crash course in Biology on YouTube.
It starts out with a bit of chemistry (bonding, water) then gets into some cell biology (including respiration, photosynthesis, DNA replication, mitosis and meiosis), genetics (inheritance and population), evolution, taxonomy, anatomy (including body systems such as nervous, circulatory & respiratory, digestive, excretory, skeletal, muscular, immune, endocrine and reproductive), behaviour, plants and ecology.

I've only watched two and a half videos so far, but they are detailed (Level 2 and above) and informative and, most importantly, accurate. Each clip is 10-15 minutes long. Here's the one about the immune system.

There also appear to be some crash courses in other things, like History.

What a wonderful world

Gives me goosebumps.

Science isn't personal: Evolution

I just watched this 10 min video from Qualia Soup about what evolution is, phrased particularly as an argument against people who don't accept it. It has good narration and clear animations to explain important mechanisms of evolution and misconceptions people have about them.

It reminded me that Qualia Soup also has some other good things to say that relate to perception and science:

• open-mindedness
• skewed views of science - how personal bias can get in the way of understanding

Bird brains - song, speech, and genes

Bird brains (Nova Science)
We can learn to talk - how? Studying bird brains can help us find out. This video covers the following.

• How complex is bird song?
  Recordings slowed down sound more musical than you think, and have inspired at least one famous composer.
• What parts of the brain do birds use when singing and listening to song?
  The same parts as we use to speak and listen to speech, as revealed by functional MRI.
• Do birds stutter?
  Yes, some do! And the difference in brain function (from normal singing birds) is similar to the differences human stutterers show.
• Finding a mutant FOXP2 gene (the language gene) involved in an inherited speech disorder by studying an affected family, and then finding FOXP2 in birds and how it relates to song learning.
• The search for other genes that might explan why we can speak, and birds can sing, but other species (e.g. chimps) can't.