Test review – enzymes, respiration, photosynthesis

February 15th, 2012

Please use some time in class to go over your test papers and make corrections as necessary.  It is not just important to write down the correct answer.  It is more important to understand WHY that is the correct answer and why your response was not correct.  You may use each other for help in this.  Please visit me during tutorials with any issues or misunderstandings. enz resp photo test marker

E3 Innate and learned behaviour

February 6th, 2012

pavlov cartoon from mobile.pistonheads.com

Can you distinguish between innate and learned behaviour?

What are some examples of behaviour in living organisms that are innate or learned?

What is taxis and what is kinesis when referring to types of behaviour?

You are then going to do a lab (yay!) where you design an experiment to investigate innate behaviour in invertebrates.  Lab sheet here: Invertebrate behaviour lab

You need to be able to analyse experimental data for these kinds of experiments in terms of the effect of this behaviour on chance of survival and reproduction (it all boils down to this – see Freud or Dawkins!).

Discuss how the process of learning can improve the chance of survival.

Outline Pavlov’s experiments into conditioning of dogs.  [Include conditioned and unconditioned stimuli and response]

Outline the role of inheritance and learning in the development of birdsong in young birds.

Here is a useful resource from Mr Taylor.

The human brain

January 26th, 2012

my brains - let me show you them by Liz Henry on flickr

Here is a useful presentation we will use in class.

  1. Label a diagram of the brain.  Annotate the diagram to include functions of the parts.
  2. Explain how animal experiments, lesions and FMRI scanning can be used to identify the brain part involved in specific functions.
  3. Explain sympathetic and parasympathetic control of heart rate, movement of the iris and blood flow to the gut.
  4. Explain the pupil reflex and discuss the concept of brain death and the use of the pupil reflex in testing for this.
  5. Outline how pain is perceived and how endorphins can act as painkillers.

Practice drawing!

January 19th, 2012

In preparation for the upcoming exams it is time to review an important skill – drawing, labelling and annotating diagrams.  Check out this presentation from Mr Taylor and practice, practice, practice!

The questions and answers to the last review quiz on Topic 2 can be found on the portal here: \\Server17\stures$\High School\Science\Science Subjects\Biology\IB BIOLOGY.

Neurotransmitters and synapses

January 17th, 2012

This is part of Option E4.  Here is an excellent resource from Mr Taylor that we’ll use.

We should aim to understand that some nervous pathways are excitatory and some are inhibitory, and how these interact at synapses.

We should also be able to explain how psychoactive drugs affect the brain and personality, and give examples of excitatory and inhibitory drugs.

We need to explain the effects of THC and cocaine on the brain and discuss the causes of addiction.

We’ll use this awesome resource from the University of Utah as well – Mouse Party!

This video is good review of the nervous system work from Semester 1, plus, towards the end, clear explanations of inhibitory and excitatory messages.


Option E – Neurobiology and behaviour

January 9th, 2012

Mr Gray Eyes by Tim in sanhazzay on flickr

Here is the syllabus guide for this topic. Option E – syllabus guide

We’ll be using notes and resources from click4biology.  Also these two presentations from Mr Taylor.  E1 and E2.

The first section is all about stimulus and response, so we’ll recap a bit of the nervous system, particularly the stuff on reflex arcs.  We’ll then move on to explain how animal responses can be affected by natural selection.  You need to investigate two examples of this.  You can use the blackcap bird (Sylvia atricapilla) as one, and any other of your choosing.

Moving on to perception of stimuli, we’ll study both the eye and the ear.  You need to be able to label a diagram like this one: Eye diagram We’ll then do a dissection so you can identify the parts properly.

You will also have to:

  • annotate a diagram of the retina to show cell types and direction of light movement
  • compare rods and cones
  • explain the processing of visual stimuli (edge enhancement and contralateral processing)

We’ll then move on to the ear, and you will need to be able to label a diagram and explain how sound is perceived.


IVF role play

November 25th, 2011

sperm injection into egg on wikimedia commons

We are going to try something a little different to help us learn about the process of IVF, and the ethical considerations that go along with it.  Here’s the situation:

A couple have been trying to conceive for over 3 years.  They have had 2 miscarriages. They are considering IVF as their next step. The man is really keen to go ahead with it, but his wife is skeptical.  They have an appointment with a doctor who is a specialist in the area of fertility and IVF.

What to do:

  • Get into groups of 3.
  • Each person will have their own role to play – decide who is going to be the doctor, who is going to be the woman and who is going to be the husband.
  • The doctor must become knowledgeable about the process of IVF, so that s/he can explain it to the couple and answer any questions they may have.
  • The woman must be ready to listen, but also have a well thought out list of concerns about the negative aspects of this treatment and the ethical considerations she is worried about.
  • The husband must have his arguments ready as to why he thinks the treatment would be a good next step for them, and address any of his wife’s concerns.
  • Spend about 30-40 mins researching your role.
  • Role play the interview between the doctor and the couple.
  • Reflect on the process – what difficulties did you find? Is there a “right” answer to this problem? Include your thoughts in a comment on this post.

Human reproduction

November 18th, 2011

Egg and sperm by Wellcome Images on flickr

No – it’s not a picture of a sunflower.  Look closely!

Here is what we will cover in the core material.

  • Draw and label diagrams of adult male and female reproductive systems.
  • How do hormones control the menstrual cycle? (Link to Endocrine system)
  • Relate hormonal changes to thickening of uterine lining, ovulation and menstruation.
  • What are the roles of testosterone in males?
  • Explain the process of IVF and discuss the ethical issues associated with it.

A good presentation can be found here.  Some great videos on this unit have been produced by NOVA.  Watch in segments or all at once.

Higher level material in this presentation.  We need to learn the details of spermatogenesis and oogenesis.  Your textbooks are pretty good on this as well, so read the relevant chapters.  We’ll get into the processes of fertilization, pregnancy and childbirth.

The kidney

November 8th, 2011


OK – this is the next-to-last section of the syllabus before we begin our options.  Here are some of the key points we’ll learn:

  • What is excretion? (And what isn’t)
  • How to draw and label a diagram of the kidney.
  • What a nephron is, how to annotate a diagram of one to help explain the processes of ultrafiltration and reabsorption.
  • What is osmoregulation, and what role do hormones play in it?
  • What are the differences between concentrations of various components in blood and urine, and the reasons for those differences.

We’ll again use this wonderful presentation from Mr S Taylor as well as our textbooks.  In addition, once we’ve completed this topic, you could watch this video.  It’s a little complicated, so I wouldn’t recommend watching it at the start, but after we’ve covered some of the theory.

Another useful review powerpoint from Mr Hobbins: 11.3 The Kidney



How do you make a hormone?

November 2nd, 2011

Illu_endocrine_system from wikimedia commons

Ask Mr. Hobbins the answer to that one!

Next up is the Endocrine System, which consists of glands that produce hormones that travel in the bloodstream to various sites of action.  We’ll look at this from the perspective of coordination and control, so will be defining the term homeostasisand looking at examples of this in the body.

Questions we’ll tackle:

  • What is the endocrine system and how does it function?
  • What is homeostasis and how does it work?
  • How is body temperature is regulated?
  • How are blood glucose levels maintained?
  • What’s the difference between type I and type II diabetes?

Another great presentation from Mr Taylor.