Monthly Archives: March 2010

Revision of Unit 1: Cells in Action

animal cell cake

This is a model of an animal cell made from cake showing the different organelles of a typical cell. The nucleus is shown by the freckle, mitochondrian was shown by the purple jelly beans, the lysosomes were the yellow jelly beans, the centrioles was the musk sticks which were then placed on the cytosol (icing), the vaccuole was shown by two freckles placed upside-down, the endoplasmic reticulum was made with yellow snakes and the rough endoplasmic reticulum was made with yellow snakes with 100’s and 1000’s laces on top to make the ribosomes and for the golgi compex was made by placing a pink snake on the icing.

This activity was enjoyed by the year 11 biology group. Making a model of a cell meant that we could relate to what a real one looked like. This made it easier to remember the names of parts of the cell and what their function was.

Chapter 1 (Cell Discovery and Exploration): Stephanie and James

Chapter 2 (Cell Structure and Function): Chris and Melissa

Chapter 3 (Composition of Cells): Charlotte and Catherine

Chapter 4 (Cell replication – Mitosis and Meiosis): Monique and Chloe

Revision of Unit 1: Cells in Action

cell diagram

You may like to create a set of Flashcards to help you to revise the first terms work. I have started one set here: Unit 1: Cells in Action Flashcards

Go to Free Online Flashcards and register as a new user. Use the glossary in the back of your text book to list the new words from each chapter and their definitions. You can use the flashcards as a quiz or for revision. Limit yourself to 10 to 20 cards per set.

Mitosis – Cell replication

mitosis in an African globe lily endosperm

Photo Source

This week we have started Chapter 4: Cell Replication, looking at how cells divide for growth, maintenance and repair. Watch the Cells Alive animation that shows the four stages of Mitosis – Prophase, Metaphase, Anaphase and Telophase. The in-between phase is Interphase, when the chromosomes are not visible. What stage is shown in the electron micrograph above? How can you tell?

This site, at NOVA Online, shows how mitosis and meiosis compare. The McGraw-Hill site also has a good animation showing mitosis and cytokinesis (division of cytoplasm and formation of two separate cells).

The most recent edition of New Scientist has an interesting article about how bone cells form –  bone marrow cells can be induced to form bone, fat or blood depending on chemical and physical cues. In an experiment performed at the University of Chicago, scientists induced bone marrow cells to form bone cells in angular moulds (star-shaped or rectangular) and fat cells in curvy moulds (circles and flower shapes).

Effect of Temperature on Plasma Membranes

beetroot prac large

Test Tube D (added later than others), Test tube C, test tube B and test tube A

The prac was aimed to show us the effect of different environmental temperatures on a plant plasma membranes.

Test tube A contains a beetroot core placed in 70 degree celcius water,

Test tube B contains a beetroot core placed in a 50 degree celcius water,

Test tube C contains a beetroot core placed in  room temperature water,

and test tube D contains a beetroot core, frozen overnight and then placed in water.

We found that treatments to Test tube A and D had the most  effect on the beetroot core. This is because the temperatures ruptured membranes allowing the red pigments inside the beetroot core to escape! The hotter or colder the temperatures were, the more membranes burst and more colour was released. The colour is contianed in plastids within the cell membranes of the beetroot.

Brilliantly written by Year 11 VCE biology students,

Chloe Wood the fantastic and Emily Huglin the awesome!