Thinking Allowed

ghosts of semesters passed by foreverdigital on flickr

Here are the syllabus guides for the core (SL) and HL topics for the entire IB Bio course.  The syllabus guides for the options we have studied are in previous posts.

For SL – you need TOPICS 1, 2, 3, 4, 5 and 6 only.

For HL – you need all the above PLUS TOPICS 7, 8, 9, 10 and 11.

Topic 1 – Statistical Analysis 2009 Syllabus   Topic 2 – syllabus outline  Topic 3,7,8 – syllabus outline   Topic 4 – Syllabus outline  Topic 5 – syllabus guide  Topic 6 – syllabus outline  Topic 9 – Syllabus outline  IB Biology HL Topic 10 – syllabus guide  Topic 11 – syllabus guide

Before you know it, mocks will be over, then Easter break, then in a few short weeks it will be May and you’ll start the REAL IB exams… and then graduation and tears of joy and sadness and a new chapter will begin…. One step at a time.  Keep studying.  It will end.

Check out lottolab.  Watch the TED video and then play around the site.  There are loads of optical illusions to keep you entertained.

And now get back to your mock revision….Friday 19th March is looming!

Eye see you! by dotbenjamin on flickr

We’ll start by looking at the different kinds of receptors that humans have, then focus on the photoreceptors in the eye and mechanoreceptors in the ear.  Click4biology is useful, as is this presentation by Mr Taylor in Bandung.

You need to be able to label a diagram of the eye like this one: Eye diagram

We’ll also do an eye dissection so you can relate the diagram to “reality”.  We’ll compare the different types of photoreceptors that are on the retina, namely rods and cones.  We’ll explain contra-lateral processing (right brain processing information from left eye, and vice versa). And finally we will explain certain kinds of optical illusions by looking at edge enhancement.

We’ll label a diagram of the ear and explain how sound is perceived.  Here are some questions for consideration:-

Why do we have two ears?  What role does the pinna play in other animals? Can fish hear? What range of sounds can the human ear hear? What is a cochlear implant and how does it work?  What does it mean to be tone deaf or have perfect pitch?

addiction by alancleaver_2000 on flickr

Here are the big questions for us to tackle in this section:

• How does decision-making occur in the CNS?
• How do psychoactive drugs affect the brain and personality?
• What the physiological effects of THC and cocaine?
• What are the causes of addiction?

We’ll use this presentation from Mr Taylor.  And, as usual, click4biology is a great resource.  Also, for fun, check out this site.  You’ll find some very entertaining mice!

Thanks to Mr Hobbins for this powerpoint. E4 Neurotransmitters and Synapses

The syllabus guide for this topic: Option E – syllabus guide

We are starting option E with a look at the nervous system.  Check out this excellent presentation from Mr Taylor.

What are some examples of reflexes that exist in humans?  Are there some that exist in babies but not in adults?  Do other animals have reflexes that we don’t have?  Do plants have reflexes?  What is the purpose of a reflex action? 

Here are some questions we need to answer:

1. What is the difference between innate and learned behaviour?  How can the process of learning improve the chance of survival?  Give examples.
2. What is the difference between taxis and kinesis?  Give examples of each.  How could these be investigated in the lab?
3. What experiments did Pavlov carry out on dogs?  What is the difference between unconditioned and conditioned stimuli?  What is the difference between unconditioned and conditioned response?
4. What role do genetics and learning play in the development of birdsong in young birds?

This presentation from Mr Taylor in Bandung is excellent, as is click4biology.

And we’ll finish this section by doing a design lab – you need to design an experiment to investigate innate behaviour by either taxis or kinesis.  This will just be a design exercise – we won’t actually carry out the lab. Here are the criteria: Design lab criteria

sweet, sweet honey by BotheredByBees on flickr

There are several issues to consider when choosing what we eat and what we buy to eat. 

Is it ok for us to consume animal products such as honey, eggs, milk and meat?  What are the ethical issues concerning including these in our diet?  Is it culturual?

Discuss the concept of food miles.  Is it appropriate for consumers to choose foods that minimize food miles?

We are going to do a little role-playing.  Here are two scenarios:

You are a new mother of a 2 week old baby.  Throughout your pregnancy you read a lot about breastfeeding vs bottle-feeding.  At your first doctor’s appointment since giving birth, the doctor asks you which method you have chosen, and why, and how it is going.  Script the conversation between you and the doctor.  Do some research to find out the composition of breast and bottle milk, and discuss the benefits and drawbacks of your chosen method.  Include ethical and social issues as well as medical ones.

You are a doctor who has recently confirmed a diagnosis of type II diabetes for a particular patient.  Script a conversation between you and your patient that includes what the causes and symptoms are, the relevance of ethnicity, what the dangers are, and any dietary advice (with justification).

We are going to use click 4 biology to help us through this section.

You need to be able to:

• Calculate the body mass index (BMI) of a person.  Know the correct units.
• Use BMI to distinguish between being underweight, normal weight, overweight and obese.
• Recognize the limitations in using BMI alone as an indicator of weight.
• Outline the reasons for increasing rates of clinical obesity in some countries.  There are several.
• Outline the consequences of anorexia nervosa.

fine crop of rice by shop boy on flickr

Did you know that per 100g, carbohydrates and proteins contain similar amounts of energy whereas fats contain more than double that?  Actual figures are: 1760 kJ for carbohydrates, 1720 kJ for protein and 4000 kJ for fats (per 100g).

Differences exist between various ethnic groups in terms of their main dietary source of energy.  Your task will be to research different ethnic groups that use rice, wheat, cassava, maize, fish and meat as their staple energy source, and to compare their diets.

MSG by PunkJr on flickr

In addition, we will consider that there are social issues relating to inappropriate diets, especially in the developed world.  There is also highly effective marketing of unhealthy foods by profit-making companies (I saw a TV ad recently espousing the benefits of MSG!).  With this in mind, you must be able to explain the possible health consequences of diets rich in carbohydrates, fats and proteins. [Consequences of an excess of each type of nutrient should be explained separately.]

What makes us stop eating?  We have an appetite control centre in the brain.  Do some research and find out how it works.