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In rainforest areas, young leaves appear to be red..shades of red. They are more nutritious
28 Sunday Sep 2014
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26 Friday Sep 2014
Posted hsc question, resource
inThis reference discusses the poor collaboration between these scientists.
It also discusses the significance of the discovery of the structure DNA.
note RELIABILITY of the source.
I HAVE NOT USED THIS SITE BEFORE THAT I CAN REMEBER. HOWEver I AM COFIDENT THE SOURCE IS RELIABLE BECAUSE;
It refers to the work of Lyn Elkin, California State University. I have read her work.
The information is consistent with other sources. (Remember the video about Rosalind Franklin. This was produced by PBS IN America, a well known source of news, science documentaries.)
It s consistent with biographies I have read about Franklin. Consistent with our text books.
Published in 2008, relatively recent.
22 Monday Sep 2014
Normal hearing
1/ sound wave
2/ the pinea directs sound wave to the ear drum or tympanic membrane
3/ the ear drum vibrates..sound energy changes to kinetic energy
4/ the ear drum transfers this energy to 0ssicles
5/ at the oval window this kinetic energy causes the fluid in the cochlea to vibrate
6/ the vibrating fluid causes hairs in the cochlea to move.(each hair responds to a specific frequency)
7/ this changes the permeability of the hair cell membranes to change creating an action potential.
8/ these action potentials pass to the auditory nerve.
cochlea implant
This device replaces the functions of the outer and middle ear.
1/. A microphone behind ear picks up sound
2/ a speech processor in the chest pocket converts sound into a digital signal
3/ digital signal sent to transducer behind the ear.
4/ digital signal sent to a transmitter inside skull
5/ signal sent to array of surgically implanted in cochlea
6/ electrodes stimulate auditory nerve.
22 Monday Sep 2014
Note an alarm model is available at school.
Evaluation.
Estimates of upto 2 million deaths pet year and 500 000 cases of blindness have been associated with vitamin A deficiency or VAD
VAD is common in poor countries where the main food is rice with little fresh vegetables or meats. The world health organisation program’s promote vitamin A supplements, the production of fresh vegetables , the raising of livestock, and the encouragement of breast feeding.
Breast feeding promotes a strong immune system which is critical as VAD depletes the immune system making individuals, particularly babies prone to disease.
golden rice offers an invaluable addition to existing strategies. The rice is cheap, a rich source of vitamin A and sustainable..produced year after year.
Environmental groups argue that golden rice has little nutritional value, is a distraction from more important strategies and may well have unexpected side effects in relation to humans andthe environment. The money spent in researchinginto golden rice could have been better used.
However, If a person is starving or suffering from vitamin A deficiency, golden rice should be introduced to minimise human suffering and prevent the onset of numerous diseases. It’s introduction should be coordinated with existing strategies to fight VAD.
22 Monday Sep 2014
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Steps involved in the production golden rice.
1/. The genes involved in the production of beta carotene (vitamin A) are removed from the daffodil DNA using restriction enzymes.
2/ the same restriction enzyme is used to cut a bacterial plasmid…a circular piece of DNA.
3/ the daffodil genes are added to the plasmid and joined together using a lipase enzyme.
4/. This plasmid is then allowed to mix with the rice DNA. this infect inserts the plasmid and daffodil genes in rice DNA.
5/. The rice embryo is now crossed with a local variety of rice to produce golden rice.
22 Monday Sep 2014
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Posted by ade sarroff | Filed under resource
15 Monday Sep 2014
Posted hsc question, resource
in15 Monday Sep 2014
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The technologies we discussed today are based around
Hearing aids
Cochlear implants
Corrective lens..myopia and hyperopia
Depth perception
Head shadow
Cataract surgery SICS..small incision cataract surgery.
10 Wednesday Sep 2014
The one gene-one enzyme hypothesis is the idea that genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn affects a single step in a metabolic pathway. The concept was proposed by George Beadle and Edward Tatum in an influential 1941 paper[1] on genetic mutations in the mold Neurospora crassa, and subsequently was dubbed the “one gene-one enzyme hypothesis” by their collaborator Norman Horowitz.[2] In 2004 Norman Horowitz reminisced that “these experiments founded the science of what Beadle and Tatum called ‘biochemical genetics.’ In actuality they proved to be the opening gun in what became molecular genetics and all the developments that have followed from that.”[3] The development of the one gene-one enzyme hypothesis is often considered the first significant result in what came to be called molecular biology.[4] Although it has been extremely influential, the hypothesis was recognized soon after its proposal to be an oversimplification. Even the subsequent reformulation of the “one gene-one polypeptide” hypothesis is now considered too simple to describe the relationship between genes and proteins.[5]
10 Wednesday Sep 2014