# Confusing MCQS in MCAT Preparation



## Amna Amir (Apr 1, 2013)

here i posted some mcqs at which i found difficulty and confusions (preparation of M CAT) and shared with you .. all of you are welcomed to ans these mcqs and help me sort out my confusions ..
Moreover , i request all of you to post here the mcqs at which you find difficulty..
i do hope ,help will be there..









"Spread the knowledge by helping and sharing"

one more thing plzz try to describe your answers briefly beside just giving answers.. it would be really 'the sharing of knowledge'..
thanxxx









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1. When abacteriophage in its lytic phase carries some of the bacterium's partiallydigested chromosome with it to another host cell the process is called
a. Conjugation
b. Transformation
c. Transduction
d. Restricted transduction

2. which one istrue for Pox-viruses?
a. RNA-enveloped
b. DNA-non enveloped
c. DNA-enveloped
d. DNA-naked virion

3. A disease virus in which nerves are damaged is the
a. Yellow fever
b. Polio
c. Measles
d. Xerophthalmia

4. Gram positivebacteria are usually
a. Cocci
b. Bacilli
c. Stained pink
d. Spirochete

5. Morphologicallythe tobacco mosaic virus is the
a. Round shape
b. Tadpole like
c. Cubical shape
d. Rod shape

6. The poison,produced by bacteria during infection in host is called
a. Toxins
b.Antitoxins
c. Toxoids
d.Afflotoxins
7. Antibiotics aresynthesized by certain organisms such as
a. Penicillium
b. Actinomycetes
c. Both a%b
d. Oscilletoria

8. plant donot store carbohydrates as glucose because it is
a. attracts insect herbivores
b. dissolves in water thereby altering the osmotic balance
c. is an unstable molecule
d. would replace ribose in DNA replication

9. n which of the following flat worms the digestive system is absent?
a. tape worms
b. liver fluke
c. hydra
d. blood fluke



10. Capsium anum is the scientific name of
a. datura
b. tobacco
c.red pepper
d. black pepper

11. when yeast ispoducing wine, which of the following is not formed
a. pyruvic acid
b. acetyl co enzyme-A
c. ethanol
d. carbon dioxide
12. the function of the mitochondrialcristac is to
a. prevent escape O2 gas
b. store co-enzyme-A
c. increase the surface area of the inner membrane
d. increase the avalibility of phospholipids


13.Animals which areunable to adjust their internal salt concentration according to externalenvironment is;
a. Anhydrobiosis
b. Osmoregulators
c. Thermoregulatory
d. Osmoconformers

14. Liver is a large organ, making the body weight up to;
a. 2 -- 3 %
b. 3 -- 6 %
c. 1 -- 2 %
d. 3 -- 5 %
15. the bloodpressure in kidneys is higher that in the other organs this high pressure ismaintained because;
a. The afferent arteriole has a large diameter and efferent arteriole has asmaller diameter
b. Of the foot like process of Podocytes
c. Because of the Bowman's capsule
c. The efferent arreriole has a large diameter than the afferent arteriole

16. Which part of the Nephron maintains the normal pH of human blood?
a. Bowman's capsule
b. Ascending prtion of henle loop
c. Descending portion of henle loop
d. Collecting duct


17.Which one the following properties of water is the main contributory factorenabling homeotherms to adapt, to a range of environment?
a. Water has a high heat of vaporization
b. Water has high surface tension
c. Water has maximum density at 4 Co
d. It has a low viscocity

18. Which of the following is an endothermic?
a. Humming birds
b. Bat
c. Fish
d. Birds

19. Process of reabsorption is the movement of materials from;
a. Filtrate to Glomerulus
b. Filtrate to blood capillaries
c. Glomerulus to filtrate
d. Pelvis to filtrate

20.The nitrogenous excretory compoundsformed in Earth-worm are the;
a. Urea
b. Ammonia
c. Both a & b
d. Uric acid

21. Which one of thefollowing posses single occipital condyle?
a. Fishes & Reptiles
b. Birds & Mammals
c. Birds & Amphibians
d. Reptiles & Birds
22. Which one of thefollowing acts as a shock absorber to cushion the tibia and the femur wherethey come together?
a. Central disc
b. Ligament
c. Cartilage
d. Tendons

23. The originalfunction, in the first vertebrates, of the skeleton was to provide;
a. Support for locomotion
b. Minerals
c. blood cells
d. protection from enemies


24. The original function is still performed today by bones of the;
a. Jaw
b. Pelvis
c. Skull and rib cage
d. Thigh

25. Cross bridges,which connect the two molecules of a fibril during a muscle contraction, aremade of;
a. Troponin
b. Tropomyosin
c. Actin
d. Myosin


ifound a little bit confusions in mcqs which i posted here..
i request all of you to help me solve these confusions related to M CATpreparation


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## Prince MD Khan (Dec 3, 2012)

1.The best choice would be d.
Transduction is the process by which DNA is transferred from one bacterium to another by a virus.[SUP][1][/SUP] It also refers to the process whereby foreign DNA is introduced into another cell via a viral vector.Well as if some chromosomes are being transferred so it would be restricted transduction.

2.Best choice is c.
Refer : Pg# 76 Ist year,small pox> Ist line.

3.Best Choice is a.
Polio and measeles are skin diseases while Xerothalmia is a eye disease.

4.Best choice is a.

5.Best choice is d.

6.Best choice is c.
Toxins are general poisons.Anti Toxins fighter for toxins.Afflotoxins are toxins produced by fungus Aspergillus.

7.Best choice is c.
Refer : Pg#94,Ist year>Use and misuse of Antibiotics

8.Best Choice is c.
Plants store most of their energy as carbohydrates while animals and humand store most of their energy as fats. Despite this differnece, the primary cell energy cycle for both, the citric acid cycle, is most readily driven by glucose. 

Starch is of course a general name for polymers of glucose, primarily with 1-6 bonds but also 1-3 branches. Single starch molecules can contain several thousand glucose units. 

Storing plant energy, in seeds or from season to season as simple sugars has some difficulties. Sugar is quite soluble in water so it tends to diffuse and be lost from the plant. Also many simple organisms, bacteria and fungi, also insects, can readily consume simple sugars so this means plant sugar stores are readily attacked by other organisms. 

Starch by contrast is nearly insoluble in water, and only more advanced organisms can create the amylase enzymes necessary to convert starches to sugars. 

The breakdown of starch into sugars is energetically favored, however starch is quite stable at any reasonable environmental temperature. 

Water insoluble(almost), stable, readily degraded & accessed via enzymes, but not easily accessed by simple organisms. It's a fine energy store for plants. 
-- 
Fats(triglycerides) have an advantage in terms of energy per unit mass (9Cal/gm for fat vs 4Cal/gm for carbs), but they require a considerable and complex mechanism (beta-oxidation) to convert fat to energy. Some plants do store considerable energy as (mostly) unsaturates fats (oils).

9.*Best Answer is a.
Refer : Page#177>3[SUP]rd[/SUP] Paragraph*

*10.Best choice would be c.*


*11.Best Choice would be b.
All other are formed.*

*12.Best Choice would be c.*
*As mitochondria are energy house.There is no function of acetyl co A as it is only involved in glycolysis and krebs cycle.*
*O2 is inhaled exhaled through lungs and mouth just.*
*While phospholipids are membranous parts.*

*13.The Best choice is b.*
_*Osmoregulators*_ tightly regulate their body osmolarity, which always stays constant, and are more common in the animal kingdom.

14.The best answer is a.

15.Best answer should be a.
As due to large diameter the pressure of blood passing through kidney would be high.


16.The best choice would be b.
As the Na ions are transferredwhich maintain the basicity which is lessened due to outflow of water from descending loop oh henle.

17.Best Choice should be a.
As water is conserved there Is less heat loss.

18.Best Choice is d.
Page#18 2nd year>Ist Para.

19.Best choice should be b.
Only Blood cappilaries are capable of reabsorption.

20.Best choice would be a.
Page#9 > Excretion in earth worm > Last line

21.Best choice is d.
Birds and reptiles share several skeletal and internal characteristics. Both have five fused bones in their jaws, a single middle ear bone and an almost identical nucleated red blood cell structure. Reptiles and birds also have a single occipital condyle; this bony knob located at the back of the skull attaches the head to the neck. This single occipital condyle allows a wider range of motion than mammals and humans that have double occipitals, with some birds being able to rotate their necks more than 270 degrees.



22.Best Choice would be a.
Pg#36 > Disc-Slip > 2nd Para- Ist line

23.Best Choice would be d.
As indigenous animals were simple so they did require Protection from their enemies just.

24.Answer should be a.
I think jaw is the functional primitive part of skeleton for many years.

25.Best Choice would be d.
Page#39,2[SUP]nd[/SUP] Year > Ultrastructure of Mayofilament > 2[SUP]nd[/SUP] Paragraph


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## h.a. (Dec 6, 2011)

questin no 19 ans is glomerulus to filtrate option c not b, reabsorption is not done by blood capilaries in nephron,material move from glomerulus to filterate for reabsorption

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ans of question 16 is d collecting duct not b because The Distal Convoluted Tubule is the site of tubular secretion. This process involves the active transport of materials from the blood directly into the tubule. Examples of molecules that are secreted by the distal convoluted tubule are creatinine, drugs like penicillin, and hydrogen ions. Tubular secretion of hydrogen ions along with the reabsorption of bicarbonate ions (a biological buffer) acts as a mechanism to control blood pH.


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## Amna Amir (Apr 1, 2013)

==Prince MD Khan said:


> 1.The best choice would be d.
> Transduction is the process by which DNA is transferred from one bacterium to another by a virus.[SUP][1][/SUP] It also refers to the process whereby foreign DNA is introduced into another cell via a viral vector.Well as if some chromosomes are being transferred so it would be restricted transduction.
> 
> 2.Best choice is c.
> ...


in 18th question if a choice ( both c and d) is alo given then that choice would be correct.. am i right??

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Amna Amir said:


> in 18th question if a choice ( both c and d) is alo given then that choice would be correct.. am i right??


 in question 20 i think ans should be "both a and b" as in first year book on page 182 , the last line of 2nd last para is "they (class oligocheata) may be terristial or aquatic" but its mentioned nowhere whether its marine or freshwater ...!

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in question 13 i am still confused. look ... 1st vertebrates were pices (fishes) and i dont think they were so simple just requiring protection frm their animals... i think ans should be (a) i.e. support for locomotion. moreover the ancestors of pieces ' lower chordates' were almost sessile. whats your opinion??

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24. The originalfunction is still performed today by bones of the;
a. Jaw
b. Pelvis
c. Skull and rib cage
d. Thigh

plzz explain your ans i cant understand it 'how ans pelvis' i think question is about vestigial organs... not sure


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## Prince MD Khan (Dec 3, 2012)

h.a. said:


> questin no 19 ans is glomerulus to filtrate option c not b, reabsorption is not done by blood capilaries in nephron,material move from glomerulus to filterate for reabsorption
> 
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> 
> ans of question 16 is d collecting duct not b because The Distal Convoluted Tubule is the site of tubular secretion. This process involves the active transport of materials from the blood directly into the tubule. Examples of molecules that are secreted by the distal convoluted tubule are creatinine, drugs like penicillin, and hydrogen ions. Tubular secretion of hydrogen ions along with the reabsorption of bicarbonate ions (a biological buffer) acts as a mechanism to control blood pH.


Yah you are right.


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## Amna Amir (Apr 1, 2013)

h.a. said:


> questin no 19 ans is glomerulus to filtrate option c not b, reabsorption is not done by blood capilaries in nephron,material move from glomerulus to filterate for reabsorption
> 
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> 
> ans of question 16 is d collecting duct not b because The Distal Convoluted Tubule is the site of tubular secretion. This process involves the active transport of materials from the blood directly into the tubule. Examples of molecules that are secreted by the distal convoluted tubule are creatinine, drugs like penicillin, and hydrogen ions. Tubular secretion of hydrogen ions along with the reabsorption of bicarbonate ions (a biological buffer) acts as a mechanism to control blood pH.


from my point of view the ans of q 19 is (b) 
because in statement the word reabsorption is mentioned which take place in the proximal tubule where 'All the useful constituents of the glomerular filterate are reabsorbed in proximal tubules via blood cappliries (peri tbuler cappilaries) 
moreover in glomerulus filteration take place thus filterate move from glomerulus to proximal tubules where reabsorption take place through blood cappilarie and when filterate leaves the proxial tubules its just nitrogenous waste.

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am i right??

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==Prince MD Khan said:


> Yah you are right.


from my point of view the ans of q 19 is (b) 
because in statement the word reabsorption is mentioned which take place in the proximal tubule where 'All the useful constituents of the glomerular filterate are reabsorbed in proximal tubules via blood cappliries (peri tbuler cappilaries) 
moreover in glomerulus filteration take place thus filterate move from glomerulus to proximal tubules where reabsorption take place through blood cappilarie and when filterate leaves the proxial tubules its just nitrogenous waste.

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am i right??


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## Prince MD Khan (Dec 3, 2012)

@Amina


Amna Amir said:


> in 18th question if a choice ( both c and d) is alo given then that choice would be correct.. am i right??
> 
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> 
> ...


About 18 you are right.
About 20 answer would be d just.
[h=2]Uricotelism[/h]Back to Top

Elimination of uric acid as the main nitrogenous waste material is called uricotelism. Animals showing uricotelism are called uricotelic animals.
[h=2]Occurrence[/h]Back to Top

It is a common method seen in birds, land reptiles, insects, land snails and some land crustaceans.
Uric acid is formed from ammonia mostly in the liver and to some extent in the kidneys. The process is highly energy dependant, but is much less toxic than both ammonia and urea and it is almost insoluble in water and can be eliminated from the body in nearly a solid state, saving a lot of water. Since kidneys can handle the nitrogenous wastes only in solution, reptiles and birds pass a dilute solution of uric acid into the cloaca, where water is absorbed and solid uric acid is eliminated along with faeces. The faecal matter of certain birds like cormorants, pelicans and gannets called guano has been used for the commercial extraction of uric acid. Islands off the coast of South America are covered with guano.
Man also excretes a small amount of uric acid in his urine formed by the catabolism of nucleic acids.
[h=5]







[/h]Other Nitrogenous wastes - Allantosm, creatine, creatinine and hippouric acid are some other nitrogenous waste products excreted by mammals.
The excretory systems also show the process of evolution from simple to complex. For example flatworms like planaria have the simplest tubular excretory system called the protonephridia. Rotifers and cephalochordates also possess protonephridia. The protonephridium is a network of closed tubules some of which terminate into flame cells. These flame cells help to collect the fluids and send them out through nephridiopores which are numerous openings or pores connected to the body surface.

[h=5]







[/h] 

Protonephridia and Flame bulb in Planaria
Earthworms possess a similar simple tubular excretory system called the metanephridia. A metanephridium has internal openings or nephrostomes that collect coelomic fluid when the cilia present on the funnel shaped opening beat.
Metanephridia have both excretory and osmoregulatory functions.
*earth?worm* (?rth







w?rm







)
_n._Any of various terrestrial annelid worms of the class Oligochaeta, especially those of the family Lumbricidae, that burrow into and help aerate and enrich soil.

Also its name suggests it is terrestial.

13. i guess you're right.
[h=4]*Classification of the Vertebrata







*[/h]*The first vertebrates were fishlike. Fishes are aquatic, gill-breathing vertebrates that usually have fins and skin covered with scales. The larval form of a modern-day lamprey, which looks like a lancelet, may resemble the first vertebrates: it has the three chordate characteristics (like the tunicate larva), as well as a two-chambered heart, a three-part brain, and other internal organs that are like those of vertebrates.*
*Small, jawless, and finless ostracoderms were the earliest vertebrates. They were filter feeders, but probably were also able to move water through their gills by muscular action. Ostracoderms have been found as fossils from the Cambrian through Devonian periods, when the group finally went extinct. Although extant jawless fishes lack protection, many early jawless fishes had large defensive head shields.


About 24 give you answer later.


My question,Were you KIPSian?????  *





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Amna Amir said:


> from my point of view the ans of q 19 is (b)
> because in statement the word reabsorption is mentioned which take place in the proximal tubule where 'All the useful constituents of the glomerular filterate are reabsorbed in proximal tubules via blood cappliries (peri tbuler cappilaries)
> moreover in glomerulus filteration take place thus filterate move from glomerulus to proximal tubules where reabsorption take place through blood cappilarie and when filterate leaves the proxial tubules its just nitrogenous waste.
> 
> ...


Well this question causing confusion for me too after reading view point from h.a.
About this que i had a discussion with my brother too.He said that Reabsorption is from glomerulus to filtrate as the materials are filtered into bowman's capsule so bowman's capsule has filtrate so this is reabsorption.

I guess you are right too.
Well look for the correct answer and will tell you.


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## annie khan (Nov 10, 2012)

hey all .. post some mcqs of physics too.I found physics the most tough portion of mcat.
and also some english grammer rules.They are also very very confusing.


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## Amna Amir (Apr 1, 2013)

annie khan said:


> hey all .. post some mcqs of physics too.I found physics the most tough portion of mcat.
> and also some english grammer rules.They are also very very confusing.[/QUOT
> 
> actually annie right now i am preparing for NUST . after this i will start preparation of full fledge M CAT ... i guess from 5th may i will start posting mcqs of other subjects too .. well try your own too...
> ...


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## Prince MD Khan (Dec 3, 2012)

Amna Amir said:


> annie khan said:
> 
> 
> > hey all .. post some mcqs of physics too.I found physics the most tough portion of mcat.
> ...


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## h.a. (Dec 6, 2011)

Amna Amir said:


> from my point of view the ans of q 19 is (b)
> because in statement the word reabsorption is mentioned which take place in the proximal tubule where 'All the useful constituents of the glomerular filterate are reabsorbed in proximal tubules via blood cappliries (peri tbuler cappilaries)
> moreover in glomerulus filteration take place thus filterate move from glomerulus to proximal tubules where reabsorption take place through blood cappilarie and when filterate leaves the proxial tubules its just nitrogenous waste.
> 
> ...


the filtarate appearing within glomerulus is called glomerulus filterate ,this filterate contains useful substances it have from blood, from glomerulus this filterate moves to bowman then to proximal convulted tubules where they are reabsorbed so the question is about movement of material for reabsorption and it is from glomerulus to filterate....................hope so you understand


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## Prince MD Khan (Dec 3, 2012)

h.a. said:


> the filtarate appearing within glomerulus is called glomerulus filterate ,this filterate contains useful substances it have from blood, from glomerulus this filterate moves to bowman then to proximal convulted tubules where they are reabsorbed so the question is about movement of material for reabsorption and it is from glomerulus to filterate....................hope so you understand


Material is also moved from filtrate to proximal tubules and it is the place where reabsorption takes place as also wriiten on page#13,2nd year >Reabsorption.

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==Prince MD Khan said:


> Material is also moved from filtrate to proximal tubules and it is the place where reabsorption takes place as also wriiten on page#13,2nd year >Reabsorption.


I think we should not confuse ourselves over the book statements.


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## Amna Amir (Apr 1, 2013)

==Prince MD Khan said:


> Amna Amir said:
> 
> 
> > Jazaki ALLAHu Khayran  But i still get confused due to lack of lil bit confidence.Confidence also plays a key role for success.
> ...


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## h.a. (Dec 6, 2011)

the temperature in inceneration of industrial waste products has range of
a)950c-1300c b)900c-1000c
my ans is b..... but in two mcat books its ans is a and in another 2 books its b

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@ amina amir the thing is you are confusing yourself filterate to blood capilaries is not a direct process for re-absorption it means filtrate to bowman to proximal then reabsorbed by blood capillaries its indirect. the thing is material move from glomerulus to filtrate moving forward for re absorption .


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## annie khan (Nov 10, 2012)

In text books, temperature in incenration is actually 900-1000c.
So (b) is the best answer.


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## Prince MD Khan (Dec 3, 2012)

Amna Amir said:


> ==Prince MD Khan said:
> 
> 
> > Amna Amir said:
> ...


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## Amna Amir (Apr 1, 2013)

h.a. said:


> the temperature in inceneration of industrial waste products has range of
> a)950c-1300c b)900c-1000c
> my ans is b..... but in two mcat books its ans is a and in another 2 books its b
> 
> ...


the ans must be (a) 950-1300 
its the temp used in industry to incinerate the waste products, while the temp 900-1300 is maintained in the uncineration of municipal solid waste...

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annie khan said:


> In text books, temperature in incenration is actually 900-1000c.
> So (b) is the best answer.


no annie..thats for unicipal waste products..
for industrial it must be 950-1300 by text book


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## h.a. (Dec 6, 2011)

can you please tell me where exactly it is written for industrial waste


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## annie khan (Nov 10, 2012)

h.a. said:


> can you please tell me where exactly it is written for industrial waste


Last chapter of part 2 chemistry.2nd last topic.
This temperature is mentioned in the definition of incenration process.

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Amna !!
If u check then u will find this temperature (900-1000) in the definition of inc. process
and temperature 950-1300c is used in non-rotary portion of inc. process but proper
temp. mentioned for inc. of industrial wastes is 900-1000c.


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## Amna Amir (Apr 1, 2013)

annie khan said:


> Last chapter of part 2 chemistry.2nd last topic.
> This temperature is mentioned in the definition of incenration process.
> 
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> ...


do you mean there is no diff between municipal and industrial waste??? and these are actually one thing..??
well in text book these these two processes are mentioned separately..
1. incineration of municipal waste i.e. at 900-1000 temp
2. incineration of industrial wste i. e. 950-1300 temp
if a question about incineration of solid waste is asked then both of these temp will correct..

a variation in the temp may be due to the diff in the composition of these two wastes
Well ! i am not sure about it ..


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## h.a. (Dec 6, 2011)

i am still waiting for exact ans


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## Prince MD Khan (Dec 3, 2012)

Amna Amir said:


> ==Prince MD Khan said:
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## Amna Amir (Apr 1, 2013)

==Prince MD Khan said:


> Amna Amir said:
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## Prince MD Khan (Dec 3, 2012)

Amna Amir said:


> ==Prince MD Khan said:
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> > Amna Amir said:
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## aadi (Aug 31, 2012)

please ans with reason. so3 is not dissolved in water because ; 1.the reaction does not go to completion..2 the reaction is quite slow ..3 the reaction is highly exothermic...3. so3 is insoluble in water....this q has different ans in different books..please anyone knows kindly help me..


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## h.a. (Dec 6, 2011)

the reaction is highly exothermic


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## Amna Amir (Apr 1, 2013)

==Prince MD Khan said:


> Amna Amir said:
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> > ==Prince MD Khan said:
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## Prince MD Khan (Dec 3, 2012)

The basic principle of x-ray production by bombardment of electrons on metal target is?

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The changing reactions of the detector are recorded digitally.A computer proccesses the information and reconstructs a picture of different densities over an entire cross section of the subject.Density differences of the order of one percent can be detected with CAT scans.

Can anyon explain this part of CAT-Scanner from PTB,i am not getting a single word from this.
How digitally detectors detect the changing reactions? what are changing reactions?if detector detects the information then how come computer constructs a image? that density part i cant get anything from those lines -_- :/


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## Amna Amir (Apr 1, 2013)

==Prince MD Khan said:


> The basic principle of x-ray production by bombardment of electrons on metal target is?
> 
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> 
> ...


i have a little idea about it 
as around the body of subject there is an array of several hundred dectectors in a line.when the x rays are produced by the source they pass through the body and the are absorbed by the detectors . now the diff body parts e.g bones , flesh nd tumour (in case) have diff densities and these x rays according to this density diff is absorbed in the dectectors in the form of digits .. ( as like peaks in ion dectector in spectrometry) . now the changing reactions doesnt mean the chemical reactions, it means the changing impressions in the form of density are recorded digitally .. now as computer systum is linked to the dectector and the information in the form of digits is processed in computer where digital results are converted into a picture of different densities over an entire cross section of the subject. and tumours are shown coloured .. these coloures are artifically generated by computer to aid in distinuishing antomical features.
well its my thought .. 
what yours now??


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## janeeta (Aug 12, 2013)

*Help?*

Aoa! I am preparing for MCAT Can you people give me some tips please... I am really determined to go to a medical college.


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