Success!!! 100% fertilization

Today at day 6 the embryos are 'candled'. We find 100% fertilization, all eggs are developing nicely.

We can see when the egg is placed near an overhead projector that light passes through the transparent egg shell but we see a dark shadow where the network of veins are developing and the even darker still outline of the duck embryo.

We can keep an eye on the development by using this method which is non invasive. The following link has a gallery of images to show duck development visible through candling. Click here. 
We will be able to observe any eggs that die during development and remove these from the incubator if required.

Hatching success rates in incubating duck eggs is rarely 100%, this is often due to fluctuating humidity (water) levels, not turned frequently enough or the duck not breaking through the membrane/shell if the membrane dries out. We can predict perhaps 6-8 of the 12 eggs to complete development and pip successfully.

One of our developing ducks can be seen in this photo

Spiky Tomato!

The weather is getting warmer and it's a good time to get out in the horticulture plot to plant some seedlings.

We have talked about heirloom plants in class, varieties of fruits and vegetables that were commonly grown but are now largely replaced with plants that have traits we consider to be more desirable.
Once purple carrots.....now a vibrant orange. Red, yellow and orange silver beet stems more commonly seen as white.

I returned from the Hawkes bay farmers market with a few interesting seedlings. My favourite was the Litchi Berry Tomato. I can't wait to see how this plant grows and look forward to the challenge of harvesting. Reviews suggest a delicious berry tangy flavour!!

It's easy to see how these sharp looking thorns were undesirable by plant growers and our selectively bred tomato plants with redder, larger, juicier fruits with no thorns came about.

Find out more about the Litchi Berry tomato here. If you have ideas about heirloom vegetables you would like to try out in the plot let me know.

Incubating Cayuga Duck eggs

Day one of incubation begins.

We place 12 duck eggs inside an incubator and set up a roster for turning the eggs 5 times a day (to stop embryo from sticking to the membrane on one side). We are responsible for keeping an eye on the temperature to check it stays stable at 37 degrees celcius and will when turning eggs will mist with spray of water to keep eggs moist and prevent egg drying out.

We will discuss embryo development and observe pictures of what stages our ducklings will be at during the 28 day cycle. We will compare and discuss similar stages of development in human embryos.
To find out more about incubating eggs you can click on this link.

Dissecting a cows eye

Science (ICAS) 2013 Competition

ICAS in Science is a is a skills based  Science Literacy assessment that is completed by over a million students from over 6,300 schools in Australia and New Zealand annually.  Why should you enter?

• Fun and challenging competition
• Great for CV
• Gives you an indication of skill on a national level
• HVHS students have traditionally preformed very well. 
• All students can participate - Y9 to Y13

Students sit the assessment on the 5th June, however if you want to enter you need to hand in permission slip with $8.50 to the resource centre by Friday 3rd May

Find out more here

Phenolphthalein indicator and dry ice bubbles

Click on this link to see what happens when you add the indicator Phenolphthalein to an acid or a base.
Watch cool bubble formed from Carbon Dioxide gas given off by dry ice.
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Dry ice bubbles and Universal Indicator with 10AE

As part of the pHizzing topic 10 AE and 10 SU explored the properties of dry ice. We looked at change of state and sublimation, density of carbon dioxide, and how carbon dioxide can be used to extinguish fires (in fire extinguishers).
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In this clip we see the colour change produced by the neutralisation of a known base (Ammonia diluted in water) as dry ice dissolves in water producing a weak acid (Carbonic acid). We also make 'dry ice bubbles'