IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => IGCSE/ GCSE => Sciences => Topic started by: sanity_master on May 22, 2009, 04:59:08 pm
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all the questions regarding BIOLOGY should be posted over here.....
so please dont make any new topic about bio, post all of ur questions here and im sure ur will get all the answers u need.
thank you.
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i was doing biology paper 3 from 2000 .. and those paper seam more hard than the recent ones like above 2003 . do u think its because of changes in syllabus ?? because after 2003 the papers are starting to get easier .
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every paper got its ups and downs.....examiners change....syllabuses change.....u cant really figure out a trend in difficulty....u just gotta practice and who knows.....maybe ur exam will be easy (like most of this year's exams).......
in other words....dont focus on the matter of the difficulty of any past exam....:)
i hope i said anything sensible :D
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well,, i know but i was just thinking if it was due to syllabus changes . if so then i might not have to do so me of the previous Questions or worry about them . Most of the Questions ask things that we didn't even study neither its in our books.
papers may vary in difficulty and I'm aware of that .
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They changed the syllabus in 2004, well more like they changed the paper 3.
Previously they had a "Section B", where you answered a set number of questions from a list of topics. Now, after 2004, there is only Section A with more questions and no section B-in my opinion, I find this change much better and it makes the paper easier to answer.
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Your Body's Systems
Circulatory System
Medical Illustration of the Human Heart
The circulatory system is the body's transport system. It is made up of a group of organs that transport blood throughout the body. The heart pumps the blood and the arteries and veins transport it. Oxygen-rich blood leaves the left side of the heart and enters the biggest artery, called the aorta. The aorta branches into smaller arteries, which then branch into even smaller vessels that travel all over the body. When blood enters the smallest blood vessels, which are called capillaries, and are found in body tissue, it gives nutrients and oxygen to the cells and takes in carbon dioxide, water, and waste. The blood, which no longer contains oxygen and nutrients, then goes back to the heart through veins. Veins carry waste products away from cells and bring blood back to the heart , which pumps it to the lungs to pick up oxygen and eliminate waste carbon dioxide.
Digestive System
The digestive system is made up of organs that break down food into protein, vitamins, minerals, carbohydrates, and fats, which the body needs for energy, growth, and repair. After food is chewed and swallowed, it goes down the esophagus and enters the stomach, where it is further broken down by powerful stomach acids. From the stomach the food travels into the small intestine. This is where your food is broken down into nutrients that can enter the bloodstream through tiny hair-like projections. The excess food that the body doesn't need or can't digest is turned into waste and is eliminated from the body.
Endocrine System
The endocrine system is made up of a group of glands that produce the body's long-distance messengers, or hormones. Hormones are chemicals that control body functions, such as metabolism, growth, and sexual development. The glands, which include the pituitary gland, thyroid gland, parathyroid glands, adrenal glands, thymus gland, pineal body, pancreas, ovaries, and testes, release hormones directly into the bloodstream, which transports the hormones to organs and tissues throughout the body.
Immune System
The immune system is our body's defense system against infections and diseases. Organs, tissues, cells, and cell products work together to respond to dangerous organisms (like viruses or bacteria) and substances that may enter the body from the environment. There are three types of response systems in the immune system: the anatomic response, the inflammatory response, and the immune response.
* The anatomic response physically prevents threatening substances from entering your body. Examples of the anatomic system include the mucous membranes and the skin. If substances do get by, the inflammatory response goes on attack.
* The inflammatory system works by excreting the invaders from your body. Sneezing, runny noses, and fever are examples of the inflammatory system at work. Sometimes, even though you don't feel well while it's happening, your body is fighting illness.
* When the inflammatory response fails, the immune response goes to work. This is the central part of the immune system and is made up of white blood cells, which fight infection by gobbling up antigens. About a quarter of white blood cells, called the lymphocytes, migrate to the lymph nodes and produce antibodies, which fight disease.
Lymphatic System
The lymphatic system is also a defense system for the body. It filters out organisms that cause disease, produces white blood cells, and generates disease-fighting antibodies. It also distributes fluids and nutrients in the body and drains excess fluids and protein so that tissues do not swell. The lymphatic system is made up of a network of vessels that help circulate body fluids. These vessels carry excess fluid away from the spaces between tissues and organs and return it to the bloodstream.
Muscular System
The muscular system is made up of tissues that work with the skeletal system to control movement of the body. Some muscles—like the ones in your arms and legs—are voluntary, meaning that you decide when to move them. Other muscles, like the ones in your stomach, heart, intestines and other organs, are involuntary. This means that they are controlled automatically by the nervous system and hormones—you often don't even realize they're at work.
The body is made up of three types of muscle tissue: skeletal, smooth and cardiac. Each of these has the ability to contract and expand, which allows the body to move and function. .
* Skeletal muscles help the body move.
* Smooth muscles, which are involuntary, are located inside organs, such as the stomach and intestines.
* Cardiac muscle is found only in the heart. Its motion is involuntary
Nervous System
The nervous system is made up of the brain, the spinal cord, and nerves. One of the most important systems in your body, the nervous system is your body's control system. It sends, receives, and processes nerve impulses throughout the body. These nerve impulses tell your muscles and organs what to do and how to respond to the environment. There are three parts of your nervous system that work together: the central nervous system, the peripheral nervous system, and the autonomic nervous system.
* The central nervous system consists of the brain and spinal cord. It sends out nerve impulses and analyzes information from the sense organs, which tell your brain about things you see, hear, smell, taste and feel.
* The peripheral nervous system includes the craniospinal nerves that branch off from the brain and the spinal cord. It carries the nerve impulses from the central nervous system to the muscles and glands.
* The autonomic nervous system regulates involuntary action, such as heart beat and digestion.
Reproductive System
The reproductive system allows humans to produce children. Sperm from the male fertilizes the female's egg, or ovum, in the fallopian tube. The fertilized egg travels from the fallopian tube to the uterus, where the fetus develops over a period of nine months.
Respiratory System
The respiratory system brings air into the body and removes carbon dioxide. It includes the nose, trachea, and lungs. When you breathe in, air enters your nose or mouth and goes down a long tube called the trachea. The trachea branches into two bronchial tubes, or primary bronchi, which go to the lungs. The primary bronchi branch off into even smaller bronchial tubes, or bronchioles. The bronchioles end in the alveoli, or air sacs. Oxygen follows this path and passes through the walls of the air sacs and blood vessels and enters the blood stream. At the same time, carbon dioxide passes into the lungs and is exhaled.
Skeletal System
The skeletal system is made up of bones, ligaments and tendons. It shapes the body and protects organs. The skeletal system works with the muscular system to help the body move. Marrow, which is soft, fatty tissue that produces red blood cells, many white blood cells, and other immune system cells, is found inside bones.
Urinary System
The urinary system eliminates waste from the body, in the form of urine. The kidneys remove waste from the blood. The waste combines with water to form urine. From the kidneys, urine travels down two thin tubes called ureters to the bladder. When the bladder is full, urine is discharged through the urethra.
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Some one posted this on a new topic I just posted it back here.
Your Body's Systems
Circulatory System
Medical Illustration of the Human Heart
The circulatory system is the body's transport system. It is made up of a group of organs that transport blood throughout the body. The heart pumps the blood and the arteries and veins transport it. Oxygen-rich blood leaves the left side of the heart and enters the biggest artery, called the aorta. The aorta branches into smaller arteries, which then branch into even smaller vessels that travel all over the body. When blood enters the smallest blood vessels, which are called capillaries, and are found in body tissue, it gives nutrients and oxygen to the cells and takes in carbon dioxide, water, and waste. The blood, which no longer contains oxygen and nutrients, then goes back to the heart through veins. Veins carry waste products away from cells and bring blood back to the heart , which pumps it to the lungs to pick up oxygen and eliminate waste carbon dioxide.
Digestive System
The digestive system is made up of organs that break down food into protein, vitamins, minerals, carbohydrates, and fats, which the body needs for energy, growth, and repair. After food is chewed and swallowed, it goes down the esophagus and enters the stomach, where it is further broken down by powerful stomach acids. From the stomach the food travels into the small intestine. This is where your food is broken down into nutrients that can enter the bloodstream through tiny hair-like projections. The excess food that the body doesn't need or can't digest is turned into waste and is eliminated from the body.
Endocrine System
The endocrine system is made up of a group of glands that produce the body's long-distance messengers, or hormones. Hormones are chemicals that control body functions, such as metabolism, growth, and sexual development. The glands, which include the pituitary gland, thyroid gland, parathyroid glands, adrenal glands, thymus gland, pineal body, pancreas, ovaries, and testes, release hormones directly into the bloodstream, which transports the hormones to organs and tissues throughout the body.
Immune System
The immune system is our body's defense system against infections and diseases. Organs, tissues, cells, and cell products work together to respond to dangerous organisms (like viruses or bacteria) and substances that may enter the body from the environment. There are three types of response systems in the immune system: the anatomic response, the inflammatory response, and the immune response.
* The anatomic response physically prevents threatening substances from entering your body. Examples of the anatomic system include the mucous membranes and the skin. If substances do get by, the inflammatory response goes on attack.
* The inflammatory system works by excreting the invaders from your body. Sneezing, runny noses, and fever are examples of the inflammatory system at work. Sometimes, even though you don't feel well while it's happening, your body is fighting illness.
* When the inflammatory response fails, the immune response goes to work. This is the central part of the immune system and is made up of white blood cells, which fight infection by gobbling up antigens. About a quarter of white blood cells, called the lymphocytes, migrate to the lymph nodes and produce antibodies, which fight disease.
Lymphatic System
The lymphatic system is also a defense system for the body. It filters out organisms that cause disease, produces white blood cells, and generates disease-fighting antibodies. It also distributes fluids and nutrients in the body and drains excess fluids and protein so that tissues do not swell. The lymphatic system is made up of a network of vessels that help circulate body fluids. These vessels carry excess fluid away from the spaces between tissues and organs and return it to the bloodstream.
Muscular System
The muscular system is made up of tissues that work with the skeletal system to control movement of the body. Some muscles—like the ones in your arms and legs—are voluntary, meaning that you decide when to move them. Other muscles, like the ones in your stomach, heart, intestines and other organs, are involuntary. This means that they are controlled automatically by the nervous system and hormones—you often don't even realize they're at work.
The body is made up of three types of muscle tissue: skeletal, smooth and cardiac. Each of these has the ability to contract and expand, which allows the body to move and function. .
* Skeletal muscles help the body move.
* Smooth muscles, which are involuntary, are located inside organs, such as the stomach and intestines.
* Cardiac muscle is found only in the heart. Its motion is involuntary
Nervous System
The nervous system is made up of the brain, the spinal cord, and nerves. One of the most important systems in your body, the nervous system is your body's control system. It sends, receives, and processes nerve impulses throughout the body. These nerve impulses tell your muscles and organs what to do and how to respond to the environment. There are three parts of your nervous system that work together: the central nervous system, the peripheral nervous system, and the autonomic nervous system.
* The central nervous system consists of the brain and spinal cord. It sends out nerve impulses and analyzes information from the sense organs, which tell your brain about things you see, hear, smell, taste and feel.
* The peripheral nervous system includes the craniospinal nerves that branch off from the brain and the spinal cord. It carries the nerve impulses from the central nervous system to the muscles and glands.
* The autonomic nervous system regulates involuntary action, such as heart beat and digestion.
Reproductive System
The reproductive system allows humans to produce children. Sperm from the male fertilizes the female's egg, or ovum, in the fallopian tube. The fertilized egg travels from the fallopian tube to the uterus, where the fetus develops over a period of nine months.
Respiratory System
The respiratory system brings air into the body and removes carbon dioxide. It includes the nose, trachea, and lungs. When you breathe in, air enters your nose or mouth and goes down a long tube called the trachea. The trachea branches into two bronchial tubes, or primary bronchi, which go to the lungs. The primary bronchi branch off into even smaller bronchial tubes, or bronchioles. The bronchioles end in the alveoli, or air sacs. Oxygen follows this path and passes through the walls of the air sacs and blood vessels and enters the blood stream. At the same time, carbon dioxide passes into the lungs and is exhaled.
Skeletal System
The skeletal system is made up of bones, ligaments and tendons. It shapes the body and protects organs. The skeletal system works with the muscular system to help the body move. Marrow, which is soft, fatty tissue that produces red blood cells, many white blood cells, and other immune system cells, is found inside bones.
Urinary System
The urinary system eliminates waste from the body, in the form of urine. The kidneys remove waste from the blood. The waste combines with water to form urine. From the kidneys, urine travels down two thin tubes called ureters to the bladder. When the bladder is full, urine is discharged through the urethra
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thanks alot for ur help
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can u give credit to who wrote it ?? its just amazing help ... its really really great
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it was "amachq" who posted it. +rep for him-great job!
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hey man thts great
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gr8 info. dude ;D
+REP ;)
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guys good ppt on respiratory system
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thts great
Thanks nid
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glad it helped
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here is a very useful website for the biology
http://revisioncentre.co.uk/gcse/biology/index.html (http://revisioncentre.co.uk/gcse/biology/index.html) it includes many good topics...........
http://www.s-cool.co.uk/gcse/biology.html (http://www.s-cool.co.uk/gcse/biology.html)
this also
thanks it will be helpful for all 8) 8) 8)
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Thank's all for the comments.
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Thank u v.v.much amachq n hash094!!! +rep to u both ;)
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Here is a great free revision guide for biology
http://www.crampuppy.com/1/IGCSE/biology/ (http://www.crampuppy.com/1/IGCSE/biology/)
always there to help students!
thanks
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what should i need to know for bio paper 5(practical)? ???
i really dont know wat to prepare, could anyone give some tips? ???
thx ;D
(n could any1 also give tips for other sciences practicals? thx)
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well,these tips r not from me but from examiner!
I think it might help u!
http://www.cambridgestudents.org.uk/subjectpages/biology/igcsebiology/Examiner_Tips_for_IGCSE_Biology_0610_FINAL.pdf (http://www.cambridgestudents.org.uk/subjectpages/biology/igcsebiology/Examiner_Tips_for_IGCSE_Biology_0610_FINAL.pdf)
thanks
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I NEED NOTES FOR LYMPHATICS!!
PEOPLEEEEEEEE
HELP MEEEeeeeHH
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for our syllabus this is all we need to know. Lymphatic system is really complicated if u try goin' into details. So here it is
Three functions
-The return of tissue fluid to the blood in the form of lymph fluid. This prevents fluid build-up in tissues.
-The production of lymphocytes(very imp). These r made in the lymph glands such as the tonsils, adenoids and spleen. The glands become more active during the time of an infection because they r producing and releasing large no of lymphocytes.
-The absorption of fatty acids and glycerol from the small intestine. Each villus contains a lacteal- a blind ending lymph vessel which absorbs the fatty acids and glycerol.
This is all u need to know. Don't get urself confused by trying to unlock the whole working of the lymphatic system. It's there in detail in the A levels. For now this is it. Hope uve got the functions.
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hey more doubts
:D
what all do we need to know, i mean what all do we need to know to make from these
i mean what all anaerobic stuff are we supposed to make?
wine, beer, cheese, yogurt, bread, what all?
just wanted to know that and also if someone had links to make these, if would be good.
i hate this part the most.
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http://www.cambridgestudents.org.uk/subjectpages/biology/igcsebiology/Examiner_Tips_for_IGCSE_Biology_0610_FINAL.pdf
http://www.crampuppy.com/1/IGCSE/biology/
http://revisioncentre.co.uk/gcse/biology/index.html
http://www.s-cool.co.uk/gcse/biology.html
Any other links related to bio?
if there, plz add them with the list above
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Thanks ;) useful pal!
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hey more doubts
:D
what all do we need to know, i mean what all do we need to know to make from these
i mean what all anaerobic stuff are we supposed to make?
wine, beer, cheese, yogurt, bread, what all?
just wanted to know that and also if someone had links to make these, if would be good.
i hate this part the most.
We have yoghurt making, baking, brewing
Yeast can respire without oxygen, fermenting sugars to produce carbon dioxide and alcohol.
In baking:
-a mixture of yeast and sugar is mixed with bread dough;
-the mixture is left in a warm place;
-carbon dioxide, produced by the yeast respiration, causes the bread to rise;
-the bread is then baked.
In the production of yoghurt:
-a starter culture of bacteria is added to warm milk;
-the bacteria ferment the milk sugar (lactose), producing lactic acid;
-lactic acid causes the milk protein to form a solid material.
Brewing
-Yeast respires sugar to form ethanol and CO2
-The source of sugar is usually fruit juice or grain
-The ethanol makes the drink alcoholic; carbon dioxide gives the drink its fizz. The process is called fermentation
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wow only these 3
great
other wise i would have spent time learning that cheese and ughh other boring stuff
thanks for the explanation
+rep
so basically brewing makes alcoholic drinks such as wine, beer etc ...
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da help was gud
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Can anyone describe the structure of a motor neuron and a sensory neuron.
Not the whole part, only about axons-dendrons-dendrites.
there was a question in that past papers
A motor neuron was given
State two features that distinguish it from other types of nerve cell.
Answer:
Its cell body is terminal.
Has long axon
OR
It has motor end plates
It has many dendrons and dendrites
I have highlighted the parts which i dont understand
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waiting
..
sites did not help
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the cheese mkhing is same as making yoghurt except an enzyme called renin is added to make more solid material from the milk which i think is called curd
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Can anyone describe the structure of a motor neuron and a sensory neuron.
Not the whole part, only about axons-dendrons-dendrites.
there was a question in that past papers
A motor neuron was given
State two features that distinguish it from other types of nerve cell.
Answer:
Its cell body is terminal.
Has long axon
OR
It has motor end plates
It has many dendrons and dendrites
I have highlighted the parts which i dont understand
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one more doubt
not doubt
but if anyone is free
explain the menstrual cycle if anyone is free and good at it
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hey visit http://msnbcmedia.msn.com/i/msnbc/Components/Interactives/Health/WomensHealth/zFlashAssets/menstrual_cycle_dw2[1].swf
read my explanation but plz visit the site
Each cycle takes about 28days
- At the start of each cycle, menstruation occurs-the lining of the uterus breaks down due to a drop in the levels of progesterone, and the cells and blood making up the lining are shed via the vagina. This is menstruation
- Under the influence of oestrogen from the ovaries, the uterus lining then starts to build up again, developing a mass of blood vessels so it is ready to receive a fertilised ovum
-Follicle stimulating hormone(FSH) causes a follicle in one of the ovaries to mature into an ovum.
-About halfway through the cycle, the level of oestrogen drops and there is secretion of LH(luteinizing hormone) from the pituitary gland, triggering ovulation. This is when the wall of the ovary ruptures and an ovum is released
-The remains of the follicle (called corpus luteum) starts to secrete progesterone, which maintains the uterus lining.
-Towards the end of the cycle, the corpus luteum breaks down resulting in a drop in secretion of progesterone. The lining of the uterus breaks down again
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hey hii nid..
nice site..
i have not taken bio though..
but it could help my frenz......
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that's great ;D
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site not working
???
thanks for help
plz one more question
if u dont mind,
i tried checking out websites but it did not help
the doubt is in my post above, the points which are highlighted in red
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Can anyone describe the structure of a motor neuron and a sensory neuron.
Not the whole part, only about axons-dendrons-dendrites.
there was a question in that past papers
A motor neuron was given
State two features that distinguish it from other types of nerve cell.
Answer:
Its cell body is terminal.
Has long axon
OR
It has motor end plates
It has many dendrons and dendrites
I have highlighted the parts which i dont understand
From what I know
A motor neurone has the cell body at the start of the neurone
It's dendrites are attached to the cell body
Axon is very long
Does not have a dendron
where did u get ur ans from?
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those answers by wahid wanis
i will mail them to u
send me ur mail id in forum mail
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ok lol no need for that.
im mailing them to u
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k thanks but im quite sure abt my ans....... and try getting to the site it's really good.
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if ur bored of markschemes, then u can use these.
he frames answers from markschemes
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yeah but im damn sure that a motor neurone does not have a dendron
did u visit the site???
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i will do later
i have to go sleep now
Zzzz
talk to you later
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nop
site not working
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I wonder why it's not working. It's working perfectly fine with me........well i hope it works for you cuz it's really good
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its working for me though.,,,
hey hii nid,,
manu v/s barca..today...
hope barca wins..
u gonna watch it??
NRI left for shopping..haha... :D
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it's at 11.15 (IST) so i might watch it......depends....but i know manu is gonna win and By the way NRI has gone shopping for u.
I think I'm askin Mom to get me Metallica.......i dunno whether she will..........cuz it's ur b'day day after lol.........i have lots of time for mine.
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well!..its at 12:15...
NRI asked me if i wanted guns n roses or metallica
i told her metallica
hope she doesn't forget..
hey wen is ur b'day??
i forgot
lol!!
and ya did u wish liny/lini aunty ... its her b'day today i guess...not sure though..
our teachers say the final nov 2009 timetable will be up by august..
wen did u guys receive ur final timetable?????
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we received it................hmmmmmm.................3 months back.....yup.
Heyy lini aunty's b'day is on 28th..........lol........w8s the date today
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we received it................hmmmmmm.................3 months back.....yup.
Heyy lini aunty's b'day is on 28th..........lol........w8s the date today
27th
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i know its tooooooooo late but i need 2 no da answer
in bio p6 wat was the similarity and diff. btween potato&garlic???????????/
by da way were we suppose 2 give answers refering 2 da hlf cut or da full parts???
pls reply :-*
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i wrote that the garlic have a center stem and the potato doesn't and that the inner surface of the garlic contains spaces but the potato's inside is smooth but i'm not sure if it's correct i guess we should worry about paper 3 now it's much harder than paper 6 and i guess you could have written the differences about either one of the pictures ...
good luck
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i wrote tht they both have irregular shapes. the difference i wrote isi tht garlic has visible center stem whereas potato doesnt and also tht garlich has segmeted surface with "cloves" and tht potato has a smooth surface..
another similarity is tht the both have stored startch but i feel thts not an observable similarity/feature.
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i think it's all right except that they both have stored starch because they wanted a feature that appeared in the picture
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yup,i guess thts true
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adernaline is secreated by which organ, and what is its target organ?
too tired to see from the book
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adrenaline is produced by adrenal glands located on the kidneys and it's target organ is epiglodis found in the mouth
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thanks
+rep
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your welcome ...!!
thanks for the +rep =]
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im sorry to say that adrenaline does not target the epiglottis
Adrenaline- The hormone,adrenaline circulates round the body and affects great many organs, making them respond differently at different situations.
TARGET ORGAN EFFECTS OF ADRENALINE BIOLOGICAL ADVANTAGE
HEART Beats faster Sends more glucose and oxygen to the blood
BREATHING CENTRE IN THE BRAIN Faster and deeper breathing Increased oxygenation
ARTERIOLES OF THE SKIN Constricts them Less blood to skin, more to the muscles
ARTERIOLES OF THE DIGESTIVE SYSTEM Constricts them Less blood for digestive system, more for muscles
MUSCLES OF ALIMENTARY CANAL Relax more energy available for action
MUSCLES OF BODY Tenses them Ready for immediate action
LIVER Conversion of glycogen to glucose higher energy production
FAT DEPOSITS Conversion of fats to fatty acids fatty acids available for muscle contraction
hope this helps and check the ppt
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guys great site for ull http://www.sep.alquds.edu/biology/?sf=edu3
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hey anyone has full igcse biology notes in a doc or pdf format? ive tried many online revision notes but i need something that can be printed and revised from. any help appreciated. :)
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hehe nid 333 posts :D xD
i will summarize the links in some time
im Zzz now | tired
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can anyone explain 2 me phototropisms and specifically action of auxins
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phototropism is growth in response to the direction of light
auxin is a hormone made in the tips of roots and shoots one effect of auxin is to inhibit growth of side shoots that's why a gardener who wants a plant to stop growing taller and become more bushy will cut off the shoot tip so removing the source of auxin .
1-auxin effect in shoots : auxin in the shoots move away from the light to the darker side and encourages growth by increasing cell elongation so the darker side grows more than the lighter side and so the shoot bend towards light source
2-auxin effect in roots : gravity causes auxin to collect on the lower side ( towards the ground/soil) in this case it stops cells elongating(growth) which causes the root to bend downwards .
hope it helps :)
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Auxins____
SWEETSH WHERE ARE YOU. SAIFALAN WHERE ARE YOU.
Do you all remember, the hair growing and ...
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??? looks like sweetsh did not read this