Monday, 20 March 2017

Newborn Baby Grey Kangaroo - Attenborough - Life of Mammals - BBC



  Marsupials are mammals that don't have a developed placenta. Marsupials have a very short gestation period and the joey is born in an essentially fetal state. These complete their development inside the mother's pouch. Once in the pouch the embryo climbs up their mother's body in search of a mammary gland to feed on. Some species of joeys stay in the pouch for upto a year or until the next joey is born. This fascinating video will show you how the undeveloped embryo is born and how it lives in th pouch. Kangaroos and koalas are marsupials as well as rat kangaroos and possums.

Monday, 16 January 2017

EXAM DATES

These are the exam dates for the second term:

- 6th February - E2A,B,C
- 8th February - E1B,C,D;F
- 10th February - E1A,E
- 15th February - E2D
- 16th February - E2E,F
- 8th March - E1B,C,D,F
- 10th March - E1A, E



Tuesday, 20 December 2016

Insects around the world - By Francisco Lemos

Francisco showed his amazing collection of insects at the Science Fair. It took him some time to find a suitable stand to display his collection on and eventually managed to recycle a stand from a hairdresser.


In the class, we coverd the stand with card and made individual labels with the names of all the insects. Francisco's knowledge not only includes the name of each of the species, but also the geographical areas they inhabit, the group or orders they belong to and many other physical features.
The collection included a variety of arthropods, like insects, arachnids and myriapods.







Solar Hot Dog Cooker - By Manuel Rodríguez


The Sun is a wonderful and free source of energy. It is there, just waiting to be used. It's a clean and very powerful source of energy. Spain is a particularly sunny country and learning how to benefit from the Sun's energy and using it in our interest is no doubt a way of reducing the use of other energy sources.
 In .this project we built a simple solar hot dog cooker for use on a sunny day. This project demonstrates how easy it is to make use of the Sun's energy.


 This hot dog cooker uses a reflective parabola. A parabola is a symmetric curve, that resembles the letter `u´. The focus is a point in the parabola, above the vertex, that is, it lies along the axis of symmetry.



 If we cover the parabola with a highly reflective material, such as, aluminium foil, it will act as a mirror and reflect the rays of light. The parabola is shaped so that it collects the Sun rays and focuses them at one point, This central point is called the focus. This point accumulates a lot of energy and is the most active point in the parabola. If we place the sausage along the focus, there is enough energy to cook it in a few minutes on a hot day.

 Manuel cooked various sausages this way at the Science Fair. He made the solar hot dog cooker by cutting a parabola out of a shoe box. First, he drew the parabola on graph paper using the formula y=ax2  and used it as a template .Then he covered the box with aluminium paper. He used two long scraps of cardboard to build supports for a skewer. He calculated the focus and placed a long wooden skewer at the focal point with a sausaged poked on it and left it in the Sun. Shortly after, the sasauge was perfectly cooked!

  

Friday, 18 November 2016

ESO 1 - FIRST TERM EXAM CONTENT

For the first term exam you must revise and study:
Unit 1 - The Earth in the Universe
Unit 2 - The Water Planet.

It's important to read carefully through the units and it's a good idea to underline the important parts (with a pencil). Try to think about what we have insisted on and repeated in the class.
It's also a good idea to read through the activities we he have done, the exam questions will be similar!



Monday, 3 October 2016

Investigating fingerprints - Science fair project - Paula Martínez Saenz


 My science fair project consisted of trying to find if the general pattern of fingerprints is inherited. There are three basic shapes: loop, whorl and arch. Everyone falls into one of these categories, but there are subtle differences such as positioning, amount of lines and angles. This therefore makes everyone's fingerprints unique to them. I took my family’s fingerprints and started investigating. Finally, what I saw was that the basic pattern doesn't seem to be inherited. I looked information about this and found that fingerprints are apparently formed during the third or fourth month of pregnancy and their shape depends on the different conditions of the baby inside its mother, conditions like the blood pressure or the babies posture in the womb.
 At the Science Fair, I showed my collection of fingerprints that I had gathered from family members, my results and conclusion. After explaining my project I offered people to see what type of fingerprints they had, and determine their basic shape, whorl, loop or arch. 






Thursday, 29 September 2016

Fruit Oxidation - Why do foods turn brown? - Science fair project - Antonio Agustin


 Have you ever noticed that fruits turn brown when you cut them? They turn brown when they are in contact with the air. The fruit's skin protects them, but if it breaks or is cut or damaged the fruit goes brown faster. Fruits contain enzymes (polyphenol oxidase and catechol oxidase are two common examples) that react with the O2  and with iron or copper cofactors in the fruit. A cofactor is a component that is necessary for a certain enzymatic reaction to happen. The fruit starts to oxidize and turn brown. Electrons are lost to another molecule, in this case the air. In other words, it's like an edible rust on your food!
 Antonio Agustin has done the following experiment to study the effects of different substances on fruit oxidation. Oxidation can be prevented or slowed down by not allowing O2 to get to the surface of the fruit or by reducing the oxidase enzymes in them. For example, cooking fruit destroys the oxidase enzymes in them but it's also possible to prevent browning or oxidation by covering the fruit to avoid its contact with air or by lowering the pH on the surface, that is making it more acidic.
 Antonio covered the food with different substances to try to find which prevents the food from turning brown best and why.


 He tested 4 foods: apple, avocado, potato and banana. He submerged them in different solutions: lemon juice, vinegar, clear soda, olive oil, water, salt water and a control sample.
 After observing his experiment for a few minutes he came to the following conclusion. Lemon juice, vinegar and clear soda prevent food from turning brown quickly. These liquids are acidic, they lower the pH of the food surface. Olive oil also prevents from browning because it doesn't let the oxygen reach the fruit. Water and salt water are the least effective.




 Acids prevent oxidation because they react with the O2 that comes into contact with the surface of the sample. Once all of the acid covering the surface has reacted with the O2 or it has washed off or degraded, the sample will start to go brown. Stronger acids, like lemon juice, can even destructure the oxidase enzyme. This means that the enzyme can no longer perform its original function.
 Antonio showed great interest and dedication doing this interesting experiment and explained it well at the Science Fair.