Archive for the ‘G11 HL Biology’ Category

Cellular respiration

Monday, February 7th, 2011

Respiration is NOT breathing!  Ok, now I’ve got that off my chest, let’s continue 🙂

This is going to be some of the more challenging work we cover, but it is good stuff!  Start with this presentation.  Once you feel you have a handle on that, then move on to this one.  Once again, huge gratitude to Mr Taylor in Bandung for his work. Finally, here are the basics, summarized: Cell Respiration

A few good online resources to help you through this topic:    Cellular respiration song[youtube][/youtube]

We’ll do a lab where we burn peanuts to simulate cell respiration (you said no-one had allergies, right?). Burning peanuts to simulate cellular respiration


Friday, January 28th, 2011

Endangered species by konjure on flickr

There are millions of species of our planet.  In order to make some sense of this huge variety, we classify organisms in a very specific way.  To learn more we’ll use this presentation from Mr Taylor.  Classification

HOMEWORK ASSIGNMENT:  Please do the following activity.  Details are in the document. The world by Data base  Basically you will log onto to a database and use it to find a relationship between two sets of information.  I will explain more in class, but this will be due on TUESDAY 8th FEBRUARY.


Thursday, January 20th, 2011

Evolution street sign by Colin Purrington on flickr

Evolution is the cumulative change in the heritable characteristics of a population.

This is a key unit in Biology.  We will explore the evidence for evolution provided by the fossil record, selective breeding of domesticated animals and homologous structures.  We will understand that populations tend to produce more offspring than the environment can support and how this can lead to a struggle for survival.  We’ll learn that members of a species show variation and how sexual reproduction promotes this variation.  We will address natural selection and how it leads to evolution.  And we’ll finish up by learning some examples of evolution in response to environmental changes, such as antibiotic resistance and changes in the colour of peppered moths.   This is a great slideshow on the development of antibiotic resistance.

Sound fun? It is!  Here is the link to a great presentation on this topic.  This one from Mr Hobbins is great too. 5.4 Evolution


Tuesday, January 11th, 2011

kidney beans by Dey on flickr

We are going to learn about populations and what affects them.  In particular:

  • How is population size affected by natality, mortality, immigration and emigration?
  • What does a typical population growth curve look like?
  • What are the reasons for the exponential, plateau and transitional phases?
  • What is the carrying capacity of an environment?
  • What factors limit populations from increasing indefinitely?

This is a useful presentation.  Here’s another: 5.3 Populations

And we are going to use the Lincoln Index to estimate the size of a population of kidney beans.  This is a simulation exercise, with the beans representing organisms such as woodlice.  But the beans don’t move, so are a bit more collaborative 🙂

IB Biology Lab Sheet – Lincoln Index

The greenhouse effect

Tuesday, December 14th, 2010

Greenhouse effect by e3000 on flickr

We all know a little about this important topic.  For our syllabus we must be able to answer the following questions:

  • What is the carbon cycle?  What are the main processes involved in it and how are they connected? The Carbon Cycle
  • What changes have taken place in atmospheric carbon dioxide levels over the past century? Biology – Carbon Dioxide Level – Chenille & Hori
  • What gases contribute to the greenhouse effect?
  • What is the relationship between the levels of these gases and the enhanced greenhouse effect? GREENHOUSE GASES
  • What is the precautionary principle?
  • Is the precautionary principle valid when dealing with the greenhouse effect?
  • What are the potential consequences of global warming on arctic ecosystems?

Start with this presentation.  This link is helpful in explaining what the greenhouse effect is NOT.

Ecology 101

Thursday, December 2nd, 2010

herbivore by thornypup on flickr

We are about to embark on Topic 5 so that we are ready for our field trip next semester.  Here is the syllabus guide for this section: Topic 5 – syllabus guide

This useful presentation covers the first part of the syllabus, namely Topic 5.1.  Here’s another one by Mr. Hobbins that we will use. Ecology definitions  And this is a table of the main definitions. Topic 5 – Ecology definitions

The basic concepts in this first part of ecology have to do with food chains and webs, the flow of energy through ecosystems, and the recycling of nutrients.

DNA – deoxyribonucleic acid

Friday, November 5th, 2010

Lego DNA by mknowles on flickr

This is a big topic!  And an important one. 

We’ll start by looking at the structure of DNA, then studying two important processes – replication and protein synthesis.  I will give you some handouts in class, but here are other resources you might find helpful.  I will add to this post as we find more.

This brilliant website by John Kyrk. 

These presentations from Mr Taylor: DNA structure   DNA replication   Protein synthesis core   Protein synthesis HL  

Protein Synthesis – AHL

Watch this video on how to extract DNA from strawberries.  We’ll be doing it in class.


Thursday, October 14th, 2010

Lock and Key by B K Dewey on flickr

There are a lot of questions to answer in this topic.  It is one of my favourite aspects of biology, as an understanding of enzymes relates to nearly every branch of biology.  So, here goes….

What is an enzyme?  What is an active site?  What is enzyme specificity and what causes it?  What is the “lock and key” hypothesis? What effects do temperature, pH and substrate concentration have on enzyme activity?  What is denaturation?  How is lactose-free milk made?

What is the induced fit model of enzyme action? How do enzymes catalyze reactions?  What is the difference between competitive and non-competitive inhibition?  What are allosteric sites?  What is end-product inhibition?

Here are some useful resources. Mr Taylor’s presentationEnzymes AHL  These two clips (first and second) are good for review.  This one is pretty complicated – but I’m adding it as some of you aiming for 7s may like to look at it.

Chemicals of life

Monday, October 4th, 2010

B0007705 Amino acid: Tyrosine by wellcome images on flickr

  • Can you distinguish between organic and inorganic compounds?
  • Can you identify carbohydrates, lipids and proteins from diagrams?
  • Can you explain the role of condensation and hydrolysis reactions between amino acids and polypeptides, between mono, di and polysaccharides, and between fatty acids, glycerol and triglycerides?
  • Can you compare the use of carbohydrates and lipids in energy storage?

If you can answer yes to all of the above questions, you are ready to move on….

In this section we’ll use this great presentation, and we’ll also be doing a lab. Lab – Comparison of chemical composition of food

Then we’ll need to venture into our first bit of higher level material on protein structure.  This may also be useful: Proteins AHL

Chemical elements and water

Wednesday, September 22nd, 2010

the world of water by Snap(R) on flickr

Here is the syllabus outline for Topic 3, and also Topics 7 and 8 since they are extensions of Topic 3.  Topic 3,7,8 – syllabus outline

The first section has to do with chemical elements and water.

  • What are the most frequently occurring chemical elements in living things? 
  • Why are calcium, sulfur, phosphorus, sodium and iron needed by plants, animals or prokaryotes?
  • What does a water molecule look like?
  • What are the thermal, cohesive and solvent properties of water?
  • How do these properties relate to water’s use in living organisms as a coolant, medium for metabolic reactions and transport medium?

Try this webquest (thanks Mr Hobbins) to help you cover these points: Water Web quest

This presentation might help, and so might this answer scheme!  Water Web quest MScheme

ToK link:  Some people have claimed that water has memory.  Others say this is pseudoscience.  Do some reading and make up your own minds!