The Tasmanian Devil

The small, solitary animal is nocturnal and spends most of its days burrowed into hollow logs. This marsupial is known to get very feisty when feeding, dozens of them can mob a single carcass. Scientists have also discovered that it has the most powerful bite of any living mammal in the animal kingdom. It will also fly into rage when it feels threatened by a predator - in fact it was these displays which led Early European settlers to call the creature the "Tasmanian Devil".  Their method of reproduction is also strange compared to other animals - Mothers give birth after about three weeks of pregnancy. They give birth to 20 or 30 tiny young. Once they're born, they crawl up their mothers fur and climb into her pouch. Unfortunately, the mother can't sustain this many young so only a handful survive.

Update!

This is just a quick post to say I haven't left ;) Just over a week ago, we held the Young Scientists Journal Conference, which was a great success! You can see the pictures from the day on Twitter with the hashtag #ysjournalconf. I also had a lot of end of topic tests and so on at school! But I've sent my UCAS application for zoology and marine biology, so we'll have to wait and see! But tomorrow we're off to the Isle of Wight for 3 nights - when we're there we're planning on going to the Isle of Wight Zoo, as I love photography and animals it's going to be great!!!!

Exciting times! :) 

DNA (deoxyribonucleic acid) - Profile

What is it?


As James Watson and Francis Crick famously said - "the secret of life". It's a vital part of any species, how it functions and the reactions that are carried out.



When was DNA discovered?



1953, by James Watson and Francis Crick - although as with any scientific discovery they were working as part of a team. Rosalind Franklin is often credited for her contribution to the discovery of DNA.



What's it made from?


The backbone of DNA if you like is made from sugar and phosphate. The 'rungs' if you like are made from bases - adenine, cytosine, guanine and thymine which form complementary base pairings. As its full name suggests, there's also deoxyribose sugar which makes up the structure.

These complementary base pairings combined with the deoxyribose sugar and phosphate make up the 'nucleotide', lots of these join together make up one of the DNA strands. Because there are lots of these joined together - DNA is a polynucleotide.





How much DNA do we have?


A LOT! Although sequencing human DNA is in its very early stages, we do know that human DNA has around three billion base pairings.



Can we do anything with DNA?
Surprisingly, yes. This year Barack Obama announced plans to sequence the genome of around 1 million people in the US in the hope scientists can use this information to create advanced treatments, targeting specific regions of our DNA.


How do we make more of it?


You'll see in more detail exactly how DNA is replicated in my Christmas countdown posts, but in short, DNA is copied to a molecule called RNA. This is because the organelles for protein synthesis are found in the cytoplasm but DNA is bound in the nucleus. This process of copying the DNA to RNA is called transcription. Once the RNA has left the nucleus, it joins to a ribosome where it can then make a protein. This is called translation.

The Lemon Shark

Sharks are one of the most well known marine predators, however they're experiencing a huge worldwide decline. Scientists have estimated that around 90% of the world's marine predators have been lost from our oceans since 1950. This loss is primarily due to overfishing and was entirely preventable. The demand for shark products on Asian markets are ever increasing - sharks are also suffering from habitat loss. Many shark species use specific areas such as waters and surrounding mangroves.

Bimini is an island surrounded by mangroves. In fact, the island is the westernmost district of the Bahamas - 53 miles due east of Miami. The island is actually the closest point within the Bahamas to the US. Because of its healthy marine ecosystem it's a tourist hot spot. The surrounding mangroves provide nursery areas for sharks, other fish, conch and lobster. The lemon shark is perhaps one of most significant nearby species. The lemon sharks have been studied by the Bimini Biological Field Station for over 25 years. They're large species at the top of the food chain - this makes them the apex predator. They are fully grown at about 12-15 years. Once they reach this age, they're sexually mature. From here, they pup every two years for the rest of their life. The usual litter size is between 4 and 18 young. These sharks can live for over 30 years. They can grow a staggering 3 metres long. As part of their research, the scientists tag the sharks to monitor their movement and behaviour. As a result of this tagging it was found that they actually travel very long distances, one individual was tracked for over 1000km. The main idea is that once they've tagged the shark, scientists can look at how the shark behaves and interacts with the oceans.

The Young Scientists Journal Conference

Tomorrow is our 2nd science communication conference at The Kings School, Canterbury and we'd like you to join us online tomorrow. Throughout the day we'll be posting things on social media - so check out the links below.

My Twitter -  @Sci_Sparks

The Young Scientists Journal Twitter - @YSJournal

Our website - www.ysjournal.com 

Conference Website - http://events.ysjournal.com/

Facebook - The Young Scientists Journal 

FIGHT!!!! | #PictureoftheMonth

For this month I thought I'd bring you a completely different picture, this time of two very territorial birds!

http://www.nhm.ac.uk/visit/wpy/gallery/2013/images/behaviour-birds/4742/light-path.html

How are new species formed?

Speciation is pretty much evolution in action, two species emerge from a single one. Because they share gene pools they have similar genes.


This pretty much works from the fact that new species can only form from pre-existing species. The idea is that a group of organisms from the space species can become separated geographically so they can't reproduce, this is called geographical isolation. When the two groups are completely separated, the two areas can have different environments. Like in every habitat there are some individuals which are better adapted to compete. These are more likely to survive and reproduce, this means the alleles (genes they have) are more likely to be passed onto their offspring. This means that over many generations the allele frequency increases so the individuals are better adapted to live in that environment. Eventually, the alleles present in one group 'evolve' and can become completely different to how they were initially. Because they might be completely different they won't be able to interbreed to produce fertile offspring, so they're now no longer the same species. 


Definitions


Species: A group of organisms which can interbreed to produce fertile offspring, they also share a gene pool.

#GBBO | Does Chocolate Make you Happy?

As we reach the concluding stages of the Great British Bake off - I thought I'd look at chocolate! To many across the globe, why we like chocolate is a mystery, yet we can't stop eating it (understandably!!) But in 1996, we had our first indication of what, exactly it is that makes chocolate so delicious and addictive. The study completed in 996 looked at the effect of chocolate on the brains of American women  - they found that as they ate the chocolate, endorphins were released making the women feel happy. This then fired up many other research projects which found that chocolate actually contains many other substances known to lift your mood. Take theobromine for example which can increase heart rate, making you feel more alert combined with other substances like seratonin (an neurotransmitter associated with happiness) and caffeine may well contribute to the overall feeling when you eat chocolate. Although, researchers now believe it might just be down to craving the feelings endorphins bring us!

The Elephant

Elephants, the largest land animals in the world, have a huge heart. Their heart weighs between 26 and 47 pounds! They actually have a life expectancy similar to humans - over 70 years. Also like humans they can laugh and have a pretty good memory although they can't jump. They are also very sociable and are very sensitive animals - they know when other elephants are sad or happy. As a 'hello' they wrap their trunks together as a display of affection. In total, their trunks have around 40,000 muscles! Elephants have particularly crafty ears. They have large, thin ears - they're made up of a complex network of blood vessels which work to regulate the elephant's temperature. The Elephants circulate blood around their ears to cool them down.

The Bharal (The Blue Sheep)

Contrary to the name- this sheep doesn't really look blue, or particularly like a conventional sheep! Because the sheep have a blue-ish tint, this makes them perfect for blending into the rocks and escaping their predators. This sheep is actually found up in the Himalayas around India, Nepal, Pakistan and Tibet. Their amazing horns are actually very strange - as they grow up they then grow out to the side before pointing backwards. They can grow up to around 165cm long. Because they spend most of their time up mountains they've become great climbers as they skip around the rocks eating moss, lichen and plants.

Gas Exchange in Fish | AS Biology Revision

• Fish have a small surface area to volume ratio
• This means the surface can't supply enough respiratory gases - so fish developed gills

Fish Gills

• Fish gills are behind their head
• Made up of many gill filaments stacked in a pile
• Gill lamellae at right angles to the filaments to increase surface area
• Water taken in through their mouth
• Water then forced over the gills and out through the opening on each side of their body

Countercurrent Flow (parallel flow wouldn't work!)

• Flow of water over the lamellae is in the opposite direction o the flow of blood within the lamellae
• Ensures the largest diffusion gradient between the water and blood at all times
• Blood loaded with oxygen meets water high in oxygen- diffusion oxygen from water to the blood 

CONCENTRATION GRADIENT IS MAINTAINED ALONG THE LENGTH OF THE GILLS WITH THE COUNTERCURRENT PRINCIPLE

Gill adaptions

• Large surface area (from the lamellae and filaments) - increases diffusion
• Short distance between the water and the blood
• Countercurrent Flow
• Circulation (replaces blood saturated with oxygen)