School Certificate Science MARATHON (3 Viewers)

[Forev3r]

index fossils are fossils that are found/lived in a certain period of time. they lived relatively short periods and can show evoultion as you are able to see how they changed through periods of time

what is the smallest unit of an element

 

[supre]

atoms is the smallest unit of an element offcourse.

 

[ohexploitable]

That's just UV breaking a bond and making Cl radicals...

CF₃Cl + UV Light --> CF₃· + Cl·

Cl· + O₃ --> ClO· + O₂

ClO· + O₃ --> Cl· + 2O₂

Then the Cl· repeats the process 10⁶ times and kills lots of our ozoney buddies.

haha fuck i was just studying this lol

thanks me from 2 years ago

 

[ljepoticax]

(6 marks, SC 2007 Question 64)

No-one answered this yet... Evaluate an impact on an environmental problem. In your answer, show how science can reduce the impact on society and the environment.

And my question: Explain the differences between reflective, opaque, refraction, reflection, transparent, translucent and give an example of everyday situations.

 

[ljepoticax]

Oh and here's some more questions if you wanted to answer..since i've noticed there haven't been many questions on some of these topics on the syllabus.
Anyways here are my questions:

- What is the cell theory?

- Differentiate between contagious and non-contagious diseases and how they occur, give 2 examples of each.

- List the three line of defences, include the body parts that fall under each line of defence.

- What is the law of the conversation of mass, what happens to atoms in a chemical reaction?

- Explain the role of motor, sensory and connective neurons.

- Define stimulus and response.

 

[ohexploitable]

this is our marathon please use your own

 

[cheshy]

contagious is a disease that can be caught by sneezing or coughing on a person - e.g. the flu, viruses.
non contagious diseases are diseases that you have gotten either by gene predisposition or by bad luck - e.g. cancer

 

[lath]

Oh and here's some more questions if you wanted to answer..since i've noticed there haven't been many questions on some of these topics on the syllabus.
Anyways here are my questions:

- What is the cell theory?

- Differentiate between contagious and non-contagious diseases and how they occur, give 2 examples of each.

- List the three line of defences, include the body parts that fall under each line of defence.

- What is the law of the conversation of mass, what happens to atoms in a chemical reaction?

- Explain the role of motor, sensory and connective neurons.

- Define stimulus and response.

Contagious (infectious) diseases can be spread from one person to another by direct contact however non contagious cannot. Examples of infectious diseases include colds and HIV/AIDS. Examples of non-infectious include genetic disorders (e.g. sickle cell anaemia, downs syndrome etc.) and skin cancer.

1st line of defence - outer layer of skin contains dead cells which shed pathogens and contain good bacteria which can fight invaders.
2nd line of defence - white blood cells (leucocytes) converge on pathogens, eat and digest them. Remains are in the form of pus.
3rd line of defence - antibodies in acquired immunity attach to the antigen of pathogens and disable them. They can then be consumed by leuococytes.

Law of conservation of mass states that mass can neither be created nor destroyed. As a result, the mass of the reactants = the mass of the products. This means that atoms cannot be created in a chemical reaction, they are simply rearranged to produce new compounds.

Sensory neurons send messages from organs to central nervous system. Connective neurons send messages within the CNS and motor neurons send messages from the CNS to the organs, telling them how to respond to the stimuli.

Stimulus is something that affects the body in some way and causes a reaction to occur. The response is the reaction of the CNS to the stimulus.

 

[ljepoticax]

this is our marathon please use your own

wow someone's a little over-protective. Relax, isn't this the whole purpose of bored of studies to help study and reply to threads. I never saw that it says anywhere private forum or no new visitors or some other form of statement.

 

[ljepoticax]

Contagious (infectious) diseases can be spread from one person to another by direct contact however non contagious cannot. Examples of infectious diseases include colds and HIV/AIDS. Examples of non-infectious include genetic disorders (e.g. sickle cell anaemia, downs syndrome etc.) and skin cancer.

1st line of defence - outer layer of skin contains dead cells which shed pathogens and contain good bacteria which can fight invaders.
2nd line of defence - white blood cells (leucocytes) converge on pathogens, eat and digest them. Remains are in the form of pus.
3rd line of defence - antibodies in acquired immunity attach to the antigen of pathogens and disable them. They can then be consumed by leuococytes.

Law of conservation of mass states that mass can neither be created nor destroyed. As a result, the mass of the reactants = the mass of the products. This means that atoms cannot be created in a chemical reaction, they are simply rearranged to produce new compounds.

Sensory neurons send messages from organs to central nervous system. Connective neurons send messages within the CNS and motor neurons send messages from the CNS to the organs, telling them how to respond to the stimuli.

Stimulus is something that affects the body in some way and causes a reaction to occur. The response is the reaction of the CNS to the stimulus.

Yep thats right Where's your question though?
And for those wondering what the cell theory was i only found it like this:

The Cell Theory states:
• All living organisms are composed of cells. They may be unicellular or multicellular.
• The cell is the basic unit of life.
Cells arise from pre-existing cells.

The modern version of the Cell Theory includes the ideas that:
• Energy flow occurs within cells.
• Heredity information (DNA) is passed on from cell to cell.
All cells have the same basic chemical composition.

There are three parts:
• Cells are the smallest unit of life.
• All cells come from a pre existing cell.
• All living things are made of cells.

Does anyone else have other versions of the cell theory or more simple versions?

For all my fellow year 10-ers in simpler terms (this is what my teacher told me):
1st line of defence: Skin, mouth, hair and saliva in the mouth.
2nd line of defence: White blood cells.
3rd line of defence: Antibodies. Immune system and lymphatic system.

 

[RealiseNothing]

You're in the 2009 marathon... why not post in the 2011 one derp

 

[ljepoticax]

You're in the 2009 marathon... why not post in the 2011 one derp

my bad.. i didn't notice, I just saw the title and didn't even bother to look at the dates.