Archive for the ‘G12 HL Biology’ Category

The human brain

Thursday, 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!

Thursday, 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

Tuesday, 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.

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Option E – Neurobiology and behaviour

Monday, 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.


Human reproduction

Friday, 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

Tuesday, November 8th, 2011
YouTube Preview Image

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?

Wednesday, 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.

Nervous system

Monday, October 10th, 2011

Neurons in the brain - illustration by Rebecca-Lee on flickr

Some of the questions we’ll be tackling in the next section of the syllabus (6.5) are:

Do you know what the CNS and PNS are?

Can you explain what role receptorssensory neurons, relay neurons,motor neurons and effectors play in conducting nerve impulses?

Can you draw and label a diagram of a motor neuron?

Can you define resting and action potentials?

Can you explain how nerve impulses pass along a neuron?

Can you explain how impulses travel from one neuron to the next?

Read through your textbook pages 240-246 to get a head start on this unit 🙂

And once again, a great presentation from Mr Stephen Taylor in Bandung to help you learn this stuff!

In class we will use this presentation – Nervous System

There are some useful animations here, and here that might help you visualize what’s happening.

Here is the lab we will do on reaction times:  Grade 12 IB HL Biology Reaction times lab

Muscles and movement

Tuesday, October 4th, 2011

electron microscopy of skeletal muscle by jgryall on flickr

In this unit we will be looking at the following key questions:

Why do muscles work in pairs?

What is a sarcomere and what does it have to do with muscle contraction?

How do muscles contract?

A great presentation on this can be found here.

Good animations to help explain what’s going on can be found here.


Block C immune system notes

Wednesday, September 21st, 2011
Alisa, Pratik and Sarita the immune system Define the term pathogen

Outline the role of the skin and mucous membranes in defence against pathogens.

Outline how phagocytic leucocytes ingest pathogens in the blood and in body tissues.

Describe the process of blood clotting.

Toni. Yurie. Sinchita. Biology Immune System Notes Outline the effects of HIV on the immune system. 

Discuss the cause, transmission and social implications of AIDS.

Bianca, Gio, Laura Define active, passive, natural and artificial immunity. 

Describe the production of monoclonal antibodies and their use in diagnosis and treatment.

Hong, Haruka, Soo Wan Antibiotics against bacteria and viruses Distinguish between antigens and antibodies. 

Explain why antibiotics are effective against bacteria but not against viruses.

Outline the principle of challenge and response, clonal selection and memory cells as the basis of immunity.

Daniel Shloka Caitlin ANTIBODY PRODUCTION Explain antibody production.
sona_yoshi_alessandra_vaccinations principles pros and cons Explain the principle of vaccination. 

Discuss the benefits and dangers of vaccination.