Biodiversity

http://www.nature.com/news/biodiversity-life-a-status-report-1.16523

Membrane Transport in Cells: Symport, Antiport, Co-transport [3D Animation]

Evolution

http://www.ucmp.berkeley.edu/education/explorations/tours/Trex/index.html

Chromosome 1 - The Stuff of Life

Chromosome (24) mtDNA - Lynn Margulis and the mitochondrial DNA

DICHOTOMOUS KEYS

Classification is very important to the field of biology. As we continue to discover new species, learn better techniques for analyzing relationships between species (i.e. DNA analysis) and share information internationally it is important to have systems in place to identify and classify organisms. A dichotomous key is a tool that helps to identify an unknown organism. A dichotomous key is a series statements consisting of 2 choices that describe characteristics of the unidentified organism. The user has to make a choice of which of the two statements best describes the unknown organism, then based on that choice moves to the next set of statements, ultimately ending in the identity of the unknown. Dichotomous keys are often used in field guides to help users accurately identify a plant or animal, but can be developed for virtually any object. They are particularly helpful when two species are very similar to one another.
This project is about learning how to use a dichotomous key to identify plants or animals. Through the process of creating their own dichotomous key and field guide the student will sharpen their observation and classification skills, both of which are necessary for success in upper level science courses. The student also builds an appreciation for nature through extended periods of observation.

Problem:

Learn how to make a dichotomous key. How can we use a dichotomous key to identify plants or animals?

Procedure:

• Study examples of dichotomous keys, like the ones below or others you might find in a field guide. There are a variety of ways you can design a dichotomous key, and they can be used to identify pretty much anything. Figure 1 below is a dichotomous key for types of potato chips, and Figure 2 is one for identifying organisms.
• Practice making a dichotomous key with everyday items or people. Start with the most obvious features of the item and move to more specific statements. Remember, each statement must have 2 choices. For example you might start by creating a dichotomous key to identify students in your class. Begin with very general statements: Is the student male or female? Does the student have blue eyes or brown eyes? Does the student wear glasses? Etc. You can set up your key as a flow chart, or as a grid.

         


 


 
https://drive.google.com/file/d/0BzvSoCVBhC9kN3JqS1dhSVZaR0NydWJUOVNRcTR2Z3RoUmVZ/view?usp=sharing
 


 

What is Evolution?

Dichotomous Key

The excretory system

The Excretory System is made up of the urinary system , the respiratory system (removes CO2 from the blood), sweat glands (they expel water and salt) and the liver which eliminates certain toxic substances, a small amount of cholesterol and the products resulting from the breakdown of haemoglobin. When haemoglobin is destroyed bilirubin is obtained, enters the liver and becomes one of the components of bile. Bilirubin also accounts for the yellow colour of urine or even bruises.

Linking things together: Where can you find haemoglobin? what is its function? What cells contain haemoglobin? Where are these cells destroyed? Where is the bile produced? Where is it released into and what is its function?

You see? Everything is connected. This is a good activity to help you remember.

The Urinary System.

The Kidneys.
     
Each kidney has an external part (cortex), an internal part (medulla) and a hollow chamber (the renal pelvis).



Each kidney is made up of over a million nephrons, which filter the blood to produce urine.


Urine is a liquid obtained from the blood and made up of water, electrolytes (iones such as Sodium, Calcium, Potassium or Chloride that regulate or affect many metabolic processes), and waste products (mainly urea and uric acid).

Urine is produced in the nephrones in a process that consists of three phases: Filtration, Reabsorption and Secretion..

1.Filtration: Most of the water and solutes in the blood plasma filter out of the glomerulus (blood capillary) and into the Bowman's capsule (first part of the nephrone). This liquid, similar to blood plasma but without proteins, is called primary urine, and contains waste products but also many useful substances.

So, what do we need now? Can we afford losing such amount of water, nutrients, hormones, minerals?

2. Reabsorption: Useful substances must be reabsorbed (go back into the blood) while waste products will continue to the ureters.
The proximal convoluted tubule reabsorbs most of the nutrients, while the Loop of Henle reabsorbs water and ions. The distal convoluted tubule regulates the concentration of Sodium, Potassium and Hydrogen ions. Finally, the concentration or dilution of urine is adjusted depending of the body needs.

As you see, the urinary system eliminates waste products of our metabolism, but also ensures the needed balance of many ions in our internal medium and mantains blood volume and pressure.

Parts of a nephron: 

1. Bowman's capsule: it is a round sac which contains a curled-up capillary called glomerulus.

2. Proximal and distal convoluted tubules.

3. Loop of Henle. U-shaped tube which is between the proximal and distal tubules.

The nephrons lead to the collecting ducts, which drain into the renal pelvis. Then, the ureters connect the renal pelvis to the bladder, an elastic sac where urine collects.

When the bladder fills up, the micturition reflex makes the bladder contract and push the urine out via the urethra. At the beginning of the urethra there is a sphincter (ring of smooth muscle) which stays closed as long as the micturition reflex does not occur.

3R's

http://www.recyclenow.com/

LABORATORY TOOLS

Biology practical demo - How do nettles sting?

How do the lungs work? - Emma Bryce

The circulatory system

Now, the circulatory system awaits for us.

We need to learn 5 things here:
1. Function that it carries out, we already did it: nutrients, waste products...remember all that. Just think that our cells are immersed in a medium called interstitial fluid or interstitial plasma, which gives them all the nutrients they need and receives all the waste products released during metabolism. The circulatory system allows this medium to remain always the same.

2. Blood: components and functions.
Blood is a viscous fluid which flows inside vessels and is composed of blood plasma and 3 types of cells.
Give me a good definition of those four things...
OK, I'll do the first two:
a. Blood plasma is a yellowish substance made up of water and dissolve molecules (all kind of nutrients, waste products and hormones).
b. Erythrocytes or red blood cells (around 5 million per mm3 of blood) are disc-shaped, enucleated (with no nucleus) cells which contain haemoglobin, a red protein which transports O2 from the alveoli to the body's cells and CO2 back to the alveoli. Actually, most of the CO2 travels dissolved in the blood plasma and not attached to haemoglobin.
Erythrocytes are formed in the red bone marrow (connective tissue inside long and flat bones) and then destroyed, 80 to 120 days later, in the spleen.

Could you do something similar for leukocytes (white blood cells) and thrombocytes (platelets)?
What functions does the blood carry out? I would talk about 5 main functions: transportation of nutrients and residues, transportation of hormones around the body (you remember hormones,right?), defence of your body  against infections, regulation of our body temperature by moving heat from warmer areas to the cooler ones and, finally, protection from blood loss when blood vessels are broken.

3. Blood vessels.
Quite easy. You need to differentiate arteries, arterioles, capillaries, veins and venules.
Try something like this:
Veins are blood vessel which take blood back to the heart. Capillaries come together to form venules and these form veins. Their walls are thinner than artery walls because they have less muscle tissue (that's why they are different colours) and there are valves inside them which allow blood to flow towards the heart but not backwards.
Write down your paragraph about arteries and capillaries.

4. The heart.
I have posted three videos on our blog in which you'll find all you need to know. You will find 8 questions in one of them that I need you to answer.

1. Learn and practice the names of the cavities, vessels and valves.
2. Follow and describe the flow of blood through the heart.
3. Explain the meaning of the colour code. Why two colours? What does blue/red mean?
4. Imagine that you are an erythrocyte in the right atrium, how can you get to the left ventricle?
5. Draw and label a human heart. Your drawing must include: the names of the four chambers, names of the 2 atrioventricular valves and 2 semilunar valves, names of the 2 arteries exiting the heart and 6 veins entering it.
6. Can a human heart keep on pumping after being removed from the body? Why?
7. What causes the sound of a heartbeat? Hint: muscles do not sound when they contract.
8. After watching te video on Heart attacks, could you explain, using your own words, what a heart attack is?

Please, complete all these activities in your notebook, I promise I will check whether you did it or not.

5. Blood circulation.
Please, watch the video: "The heartbeat and blood circulation" available in www.anayadigital.com
Try to describe our double circuit (pulmonary and systemic circulation). Do not trust your memory too much, you'd rather write it down, just in case it could be a nice question in the test.


To start with, one tiny remark: printing out is not the same that writing down, I would say they are quite the opposite. I hope you are not printing out my posts and just gluing or glueing (both are correct) them in your notebooks, and I say it for two different reasons: first, because they have more directions than information, and second, because you learn more when you are active, deciding what is worth copying and what can be improved or completed. Actually, I am continuously asking you to do your part.

6. The cardiac cycle.
Each heartbeat has three phases. Yes, three and not two. Can you describe these 3 phases? 
I will give you a  hand: the first one is called "atrial systole" and in it, the atria (both of them) contract and the blood is pumped into the ventricles via the open atrioventricular valves.

Now is your turn.

After completing the three phases, could you locate the characteristic "lub-dub" sound of the heart in them?
Tricky question, 3 phases and two sounds (lub and dub). I will help you again: visualise the atrial systole (read the description I wrote), would you hear anything during this phase?

7. The decisive question to become a first-rate expert in circulation.
I need a long introduction. Here it goes: Ventricular systole pumps the blood into the major arteries. These arteries are elastic, so that they dilate when they receive blood, lowering blood pressure, and then contract back to their normal diameter, pushing the blood forward so that it flows through the arteries continuously, not intermittently as you may have thought.
Arteries branch out into arterioles and these into capillaries in turn. When the blood reaches the capillaries, the pressure is lower and the flow is slower which facilitates the exchange of substances between blood and cells (actually blood and interstitial plasma). 
We are almost there.
Now, the capillaries come together to form larger vessels, venules, and these will form veins. The problem is that all the pressure provided by the heart is now gone, so, and this is the question: how does the blood manage to complete the circuit and reach the atria of the heart?
Not an easy task, that's why 3 mechanisms cooperate to try to solve it.
Your answer:




http://naturalscience3doctormaranon.blogspot.com.es/?view=flipcard

Tree of Life video HD

Living things

http://www.bbc.co.uk/education/guides/z9hyvcw/revision
Animals and plants are made of cells. Tissues are made from cells of a similar type. Organs are made from tissues, and systems are made from several organs working together.