Tagged: Zondle

Feedback on Zondle Biology revision challenge part 2

The questions in this revision test were more challenging than last time.  I hope that players found them interesting and useful.

The plant transport questions at the start were well answered overall.  Osmosis is the only way water can ever cross a cell membrane and although active transport does occur in the root hair cells (pumping mineral ions such as nitrates into the cell against the concentration gradient), water cannot be directly pumped against its concentration gradient using energy from respiration.

The cloning questions were difficult but I think the low scores here were perhaps more to do with problems with my school wifi than with your abilities to answer them!  Micropropagation is the way that you learned when a small part of a plant is cut out, sterilised, washed and then added to a culture medium that triggers cell differentiation.  You probably did this experiment with explants from a cauliflower.  The aim was to produce whole new plants from these small explants.  This technique could not work with animals simply because animal’s bodies contain many more types of tissue and have a more complex internal architecture that requires a much more sophisticated genetic programme of development.

I want to talk about a few questions in the latter stages of the test that were not well answered.  I am sure there is plenty you can all learn from these.

The first was the one that asked you what was meant by a “diploid cell”.  More than half of you thought that  diploid meant having 46 chromosomes.  This is almost a trick question because of course in humans, diploid cells will have 46 chromosomes.  But diploid can be applied to any cell that has chromosomes found in homologous pairs.  The number 23 is only important to humans as for our species it is the number of homologous pairs of chromosomes found in our diploid cells.  Different species have differing numbers of pairs of chromosomes, some less than the number in humans but in many species they have more.

The second big idea question was the true or false question on whether energy is recycled in the ecosystem like carbon atoms.  It is vital you understand that there is absolutely no recycling of energy ever in an ecosystem.  Energy enters in the form of light energy being trapped by plants in photosynthesis and all this energy ultimately ends up as heat energy in the atmosphere.  To find out the details of how it gets there, please read the relevant sections on my blog.  Try the tag energy from the Tag cloud on the right of the screen.

There was one question in the quiz which not a single player answered correctly and it is the one about which type of cells produce antibodies.  Antibodies are made from a cell called a plasma cell.  Plasma cells secrete antibodies in large numbers to combat an infection.  Plasma cells are descended from B lymphocytes that have been activated by the presence of antigen.  This clonal selection theory is one of the most complicated bits in iGCSE Biology so make sure you have looked carefully at it.  The final question was about active v passive immunity.  This is not specifically mentioned in the specification so perhaps is a bit mean to include but if you can understand it properly, you understand how immunity works.  Passive immunity is the name for when antibodies are transferred, perhaps across the placenta for a foetus or in an injection as an adult.  Antibodies are made of protein and so do not exist for long in the blood – after a month or two they will all have been broken down and cleared from the blood.  So passive immunity cannot give long-lasting protection.  Active immunity is when memory cells are produced via a clonal selection response.  These memory cells can survive for an entire lifetime and so do provide long lasting protection.

By far the biggest thing you can learn from this quiz however was about virus structure.  I asked you whether “viruses are made from a different kind of cell not found in animals or plants – true or false.”  Almost everyone went for false but remember this can’t be correct:  viruses are definitely not made of cells!  They are much simpler than even the simplest cell and just consist of a protein coat with some genetic material (DNA or RNA) inside.  No cell membrane, no cytoplasm, no metabolism – just two chemicals associated into one simple particle.

Anyway I hope you enjoyed the quiz – look out for the next one on my Twitter feed and please use the comment facility on this blog to get in touch if you have any questions or want more explanations.

PMG revision quiz 2 – questions and answers

I am never sure how much information players can see about which are the correct answers.  Here is a pdf file that shows all 30 questions, the correct answer as well as all the distractor answers.

There was some good scoring in the quiz tonight – please read my blog post later for commentary on the questions, including the commonest mistakes and misconceptions.

PMG quiz 2 questions and answers

Questions and Answers for iGCSE Zondle Biology revision challenge 1

I know that some people were not able to see the correct answers after each question during the game today.

Zondle challenge 1 Q&A

The attached pdf file should show all 30 questions, the correct answers and the three incorrect answers for each question.  I hope that this pdf together with the commentary on the game will be helpful for revision for the people who played.

Next revision challenge for iGCSE Biology will be on 22-4-2015 at 2100 BST.  I hope many of you will sign up again.  New topics, new questions and lots to learn…..

Commentary on Zondle GCSE Biology Revision challenge 1 questions

I hope that those of you who played the GCSE Biology revision challenge this afternoon enjoyed the process.  I would welcome comments on this blog post along the lines of www (what went well) and ebi (even better if)….

The questions were grouped into several topic areas.

Questions 1 to 4 were on thermoregulation.  Understanding vasoconstriction, vasodilation and sweating are the key things here and if you haven’e done already, I would read my blog post on this topic.

https://pmgbiology.wordpress.com/2014/05/29/skin-a-understanding-for-igcse-biology/

Questions 5 – 9 were on plant transport and these were well answered by almost all players.  Remember that phloem sieve tubes move sucrose and amino acids around the plant.  Water and minerals are transported in xylem vessels of course, but the other distractor answers included various polymers (starch and proteins) that are made in photosynthesis in the leaves but which are too large and insoluble molecules to be transported in phloem.

Questions 10-15 were all on the bacteria in the Nitrogen cycle.  This is a tricky topic but one that rewards patient work by candidates to master it. In reality the Nitrogen cycle is not difficult to understand but it is easy to muddle the names and roles of the four types of bacteria involved.  Again there are a couple of blog posts on Nitrogen cycle that I would encourage you to read….

https://pmgbiology.wordpress.com/2014/04/12/bacteria-of-the-nitrogen-cycle-a-understanding-for-gcse-biology/

https://pmgbiology.wordpress.com/2014/04/12/nitrogen-cycle-for-igcse-biology/

Questions 16-23 were on digestive systems.  These were generally well answered although many players didn’t appreciate that peristalsis doesn’t just happen in the oesophagus: it is the process that moves the food along the entire length of the gut tube from top of oesophagus to the end of the rectum.  The role of the lacteal in transporting fatty acids and glycerol away from the villi in the small intestine is also one of the trickier topics here.  Amino acids and sugars diffuse into the blood capillaries in the villus but fatty acids and glycerol (the products of digestion of lipids) don’t go into the capillaries but instead into a separate vessel called a lacteal. This forms part of the lymphatic system and the liquid formed ends up back in the blood but effectively bypasses the liver, preventing the cells in the liver being overloaded with fatty acids following a fatty meal.

Questions 24-29 were on the heart and circulation.  There were quite a few incorrect answers here but perhaps this was because enthusiasm levels were dropping….  The flow of blood through the heart is an important topic to appreciate – into RA through vena cava, then into RV through right AV valve, then into PA through semilunar valve, then to lungs, back from lungs in pulmonary veins, into LA, through Left AV valve into LV, then into aorta through the aortic semilunar valve…..

The heart strings in the heart (chordae tendinae) are commonly misunderstood.  They play no role at all in opening or closing the AV valves (this is done simply by the balance of blood pressures in atrium and ventricle) but do provide tension to stop the valve “blowing back” and thus opening when the ventricle contracts.  Have a look at pictures of a real heart dissection to see that these tendons attach to the valve flaps and ensure they cannot blow open when the pressure in the ventricles rise during ventricular contraction.  Ask me for more detail if this doesn’t make sense.

PMG Zondle Zero 3 challenge

Just confirming the playing regulations for my two iGCSE Y11 groups with Zondle.  Create an account using the classcode I have given you.  Play the games I set for you as many times as you like, collecting “zollars” for high scores but also for repeated attempts.

At the start of next half the student in each class with the most “zollars” will be taken out for lunch at Zero 3 on the High Street and I will pay.   If you want to set your own revision quizzes on Zondle, do please have a go.  You can see the other games from people in the class under the “games set by my friends” drop down list.

Enjoy – I think this will be a great way to make revision a little more interesting…..

Feedback on Zondle Biology revision challenge part 2

The questions in this revision test were more challenging than last time.  I hope that players found them interesting and useful.

The plant transport questions at the start were well answered overall.  Osmosis is the only way water can ever cross a cell membrane and although active transport does occur in the root hair cells (pumping mineral ions such as nitrates into the cell against the concentration gradient), water cannot be directly pumped against its concentration gradient using energy from respiration.

The cloning questions were difficult but I think the low scores here were perhaps more to do with problems with my school wifi than with your abilities to answer them!  Micropropagation is the way that you learned when a small part of a plant is cut out, sterilised, washed and then added to a culture medium that triggers cell differentiation.  You probably did this experiment with explants from a cauliflower.  The aim was to produce whole new plants from these small explants.  This technique could not work with animals simply because animal’s bodies contain many more types of tissue and have a more complex internal architecture that requires a much more sophisticated genetic programme of development.

I want to talk about a few questions in the latter stages of the test that were not well answered.  I am sure there is plenty you can all learn from these.

The first was the one that asked you what was meant by a “diploid cell”.  More than half of you thought that  diploid meant having 46 chromosomes.  This is almost a trick question because of course in humans, diploid cells will have 46 chromosomes.  But diploid can be applied to any cell that has chromosomes found in homologous pairs.  The number 23 is only important to humans as for our species it is the number of homologous pairs of chromosomes found in our diploid cells.  Different species have differing numbers of pairs of chromosomes, some less than the number in humans but in many species they have more.

The second big idea question was the true or false question on whether energy is recycled in the ecosystem like carbon atoms.  It is vital you understand that there is absolutely no recycling of energy ever in an ecosystem.  Energy enters in the form of light energy being trapped by plants in photosynthesis and all this energy ultimately ends up as heat energy in the atmosphere.  To find out the details of how it gets there, please read the relevant sections on my blog.  Try the tag energy from the Tag cloud on the right of the screen.

There was one question in the quiz which not a single player answered correctly and it is the one about which type of cells produce antibodies.  Antibodies are made from a cell called a plasma cell.  Plasma cells secrete antibodies in large numbers to combat an infection.  Plasma cells are descended from B lymphocytes that have been activated by the presence of antigen.  This clonal selection theory is one of the most complicated bits in iGCSE Biology so make sure you have looked carefully at it.  The final question was about active v passive immunity.  This is not specifically mentioned in the specification so perhaps is a bit mean to include but if you can understand it properly, you understand how immunity works.  Passive immunity is the name for when antibodies are transferred, perhaps across the placenta for a foetus or in an injection as an adult.  Antibodies are made of protein and so do not exist for long in the blood – after a month or two they will all have been broken down and cleared from the blood.  So passive immunity cannot give long-lasting protection.  Active immunity is when memory cells are produced via a clonal selection response.  These memory cells can survive for an entire lifetime and so do provide long lasting protection.

By far the biggest thing you can learn from this quiz however was about virus structure.  I asked you whether “viruses are made from a different kind of cell not found in animals or plants – true or false.”  Almost everyone went for false but remember this can’t be correct:  viruses are definitely not made of cells!  They are much simpler than even the simplest cell and just consist of a protein coat with some genetic material (DNA or RNA) inside.  No cell membrane, no cytoplasm, no metabolism – just two chemicals associated into one simple particle.

Anyway I hope you enjoyed the quiz – look out for the next one on my Twitter feed and please use the comment facility on this blog to get in touch if you have any questions or want more explanations.

Commentary on Zondle GCSE Biology Revision challenge 1 questions

I hope that those of you who played the GCSE Biology revision challenge this afternoon enjoyed the process.  I would welcome comments on this blog post along the lines of www (what went well) and ebi (even better if)….

The questions were grouped into several topic areas.

Questions 1 to 4 were on thermoregulation.  Understanding vasoconstriction, vasodilation and sweating are the key things here and if you haven’e done already, I would read my blog post on this topic.

https://pmgbiology.wordpress.com/2014/05/29/skin-a-understanding-for-igcse-biology/

Questions 5 – 9 were on plant transport and these were well answered by almost all players.  Remember that phloem sieve tubes move sucrose and amino acids around the plant.  Water and minerals are transported in xylem vessels of course, but the other distractor answers included various polymers (starch and proteins) that are made in photosynthesis in the leaves but which are too large and insoluble molecules to be transported in phloem.

Questions 10-15 were all on the bacteria in the Nitrogen cycle.  This is a tricky topic but one that rewards patient work by candidates to master it. In reality the Nitrogen cycle is not difficult to understand but it is easy to muddle the names and roles of the four types of bacteria involved.  Again there are a couple of blog posts on Nitrogen cycle that I would encourage you to read….

https://pmgbiology.wordpress.com/2014/04/12/bacteria-of-the-nitrogen-cycle-a-understanding-for-gcse-biology/

https://pmgbiology.wordpress.com/2014/04/12/nitrogen-cycle-for-igcse-biology/

Questions 16-23 were on digestive systems.  These were generally well answered although many players didn’t appreciate that peristalsis doesn’t just happen in the oesophagus: it is the process that moves the food along the entire length of the gut tube from top of oesophagus to the end of the rectum.  The role of the lacteal in transporting fatty acids and glycerol away from the villi in the small intestine is also one of the trickier topics here.  Amino acids and sugars diffuse into the blood capillaries in the villus but fatty acids and glycerol (the products of digestion of lipids) don’t go into the capillaries but instead into a separate vessel called a lacteal. This forms part of the lymphatic system and the liquid formed ends up back in the blood but effectively bypasses the liver, preventing the cells in the liver being overloaded with fatty acids following a fatty meal.

Questions 24-29 were on the heart and circulation.  There were quite a few incorrect answers here but perhaps this was because enthusiasm levels were dropping….  The flow of blood through the heart is an important topic to appreciate – into RA through vena cava, then into RV through right AV valve, then into PA through semilunar valve, then to lungs, back from lungs in pulmonary veins, into LA, through Left AV valve into LV, then into aorta through the aortic semilunar valve…..

The heart strings in the heart (chordae tendinae) are commonly misunderstood.  They play no role at all in opening or closing the AV valves (this is done simply by the balance of blood pressures in atrium and ventricle) but do provide tension to stop the valve “blowing back” and thus opening when the ventricle contracts.  Have a look at pictures of a real heart dissection to see that these tendons attach to the valve flaps and ensure they cannot blow open when the pressure in the ventricles rise during ventricular contraction.  Ask me for more detail if this doesn’t make sense.

Zollar leaderboard for bD1.4

There are just a couple of days left for the boys of bD1:4 to accumulate “Zollars” for the star prize of a lunch at Zero 3 next week.  Just to remind you, I will buy lunch (whatever you want) for the boy in my division with the most zollars at the start of our first Biology lesson of the new term.

If you haven’t yet signed up to Zondle, please do so as my revision games should be useful.  It is free, you don’t need to add your real name (although please choose an id that I can tell who you are…..) and get playing.  Use the class code I emailed you so you can see exactly what I want you to do.  You get zollars for playing games but also for the scores you get and you can play each game as many times as you like.

Just for your information, there are 11 boys with zollars already on the board and four players with over a 1000 zollars to their name……