# Sticky  Practice MCAT Questions



## MastahRiz (Jan 26, 2006)

*[Question #1]

*Which of the following is the mRNA start codon in most cases?

A. UAA
B. AGU
C. AUG
D. UGA

If you have an answer, please reply with* [Answer #n]* and as always, stay tuned for more questions 8)


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## Jenny (May 12, 2006)

[Answer C-AUG] ! 


Keep them coming!


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## MastahRiz (Jan 26, 2006)

*[Question #2]*

Which of the types of RNA is the smallest?

A. mRNA

B. tRNA

C. rRNA


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## andrehs (Oct 26, 2007)

MastahRiz said:


> *[Question #2]*
> 
> Which of the types of RNA is the smallest?
> 
> ...


Answer:

* [c # rRna]*


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## MastahRiz (Jan 26, 2006)

*[Question #3]*

Prothrombin is a _______ globin produced by the ______.

A. Alpha, Kidney
B. Alpha, Liver
C. Beta, Liver
D. Beta, Kidney


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## Xero (Jun 6, 2008)

Thats option 'B'


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## MastahRiz (Jan 26, 2006)

*[Question #4]* 
*[FONT=&quot]
By the way, these MCAT questions are for the American MCAT given in the US, not for medical colleges in other countries. The mcat exams in other countries are not at all similar to these practice questions.

Passage I[/FONT]*
[FONT=&quot]
A series of chemical reactions was carried out to study the chemistry of lead. [/FONT]
[FONT=&quot]Reaction 1 [/FONT]
[FONT=&quot]Initially, 15.0 mL of 0.300 M Pb(NO3)2(aq) was mixed with 15.0 mL of 0.300 M Na2SO4(aq).All the Pb(NO3)2 reacted to form Compound A, a white precipitate.Compound A was removed by filtration. [/FONT]
[FONT=&quot]
Reaction 2 [/FONT]
[FONT=&quot]Next, 15.0 mL of 0.300 M KI(aq) was added to Compound A. The mixture was agitated and some of Compound A dissolved. In addition, a yellow precipitate of PbI2(s) was formed. [/FONT]
[FONT=&quot]
Reaction 3 [/FONT]
[FONT=&quot]The PbI2(s) was separated and mixed with 15.0 mL of 0.300 M Na2CO3(aq). A white precipitate of PbCO3(s) formed. All of the PbI2(s) was converted into PbCO3(s). [/FONT]
[FONT=&quot]
Reaction 4 [/FONT]
[FONT=&quot]The PbCO3(s) was removed by filtration and a small sample gave off a gas when treated with dilute HCl. [/FONT]
*[FONT=&quot]
1. Which of the following reactions depicts the formation of the gas in Reaction 4?[/FONT]*
[FONT=&quot]PbCO3(s) + 2 HCl(aq) = PbCl2(aq) + CO2(g) + H2O(l) [/FONT]
[FONT=&quot]Na2CO3(aq) + 2 HCl(aq) = 2 NaCl(aq) + CO2(g) + H2O(l) [/FONT]
[FONT=&quot]PbCO3(s) + 2 HCl(aq) = PbC2(s) + Cl2(g) + H2O(l) [/FONT]
[FONT=&quot]PbI 2(s) + HCl(aq) = PbCl2(aq) + HI(g) [/FONT]
*[FONT=&quot]
2. The identity of Compound A is:[/FONT]*
[FONT=&quot]Pb(NO3)2. [/FONT]
[FONT=&quot]PbI2. [/FONT]
[FONT=&quot]NaNO3. [/FONT]
[FONT=&quot]PbSO4. [/FONT]
*3.**[FONT=&quot] Pb(OH)2(s) is slightly soluble in water. How would the amount of Pb(OH)2(s) that normally dissolves in 1 L of water be affected if the pH were 9.0?[/FONT]*
[FONT=&quot]Less would dissolve. [/FONT]
[FONT=&quot]The same amount would dissolve. [/FONT]
[FONT=&quot]More would dissolve. [/FONT]
[FONT=&quot]There is no way to predict the effect of the change in pH of the water. [/FONT]
*4. **[FONT=&quot]A soluble form of Pb2+can be carefully added to a solution tosequentially precipitate and separate anions present in the solution. When Pb2+is added, in what order will the following anions be precipitated?[/FONT]*
[FONT=&quot]SO42- then I- [/FONT]
[FONT=&quot]CO32- then I- [/FONT]
[FONT=&quot]SO42- then CO32- [/FONT]
[FONT=&quot]I- then CO32- [/FONT]
*5. **[FONT=&quot]How many moles of Na+ ions are there in the initial Na2SO4(aq) solution used in Reaction 1?[/FONT]*
[FONT=&quot]0.0018 mole [/FONT]
[FONT=&quot]0.009 mole [/FONT]
[FONT=&quot]0.045 mole [/FONT]
[FONT=&quot]0.090 mole[/FONT]


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## abc_123_kes (Sep 7, 2008)

whats the answer to question 4? my guess is

1) first reaction
2) 4
3) less would dissolve
4) 4
5) 3

can someone verify these


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## sparkofighter (Jul 28, 2009)

the answer of question #1 is AUG


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## ahmed nadeem (Aug 19, 2009)

1)1
2)4
3)1
4)1
5)4
these are my guesses ...but you gotta realize im not an american student


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## HeatherMarie (Aug 20, 2009)

For Question 4:
1 is PBCO3 (s) + 2 HCl = PbCl2 (aq) + CO2 (g) + H2O (l)
2 is PbSO4
3 More would dissolve (that's a guess I'm not entirely sure)
4. SO4 then I (not sure on this one either)
5. .045 moles


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## @num (Jul 20, 2011)

MastahRiz said:


> *[Question #1]
> 
> *Which of the following is the mRNA start codon in most cases?
> 
> ...


its option C.AUG


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## Sajjad 01 (Jan 4, 2012)

MastahRiz said:


> *[Question #1]
> 
> *Which of the following is the mRNA start codon in most cases?
> 
> ...


c


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## Amna Amir (Apr 1, 2013)

MastahRiz said:


> *[Question #1]
> 
> *Which of the following is the mRNA start codon in most cases?
> 
> ...


ans is ( c) ,
because UGA and UAA are stop codons , AGU codes for serine while AUG codes for metheonine that is starting codon.


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## fatima938 (Jun 11, 2013)

Ans # 1 . AUG


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## CHOCLATE (Jul 5, 2013)

The acidity of chyme stimulates 
(a).pancreatic cell 
(b).liver cell 
(c).duodenal cell 
(d).all

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MAXIMUM NUMBER OF ENZYMES OCCUR IN 
(A).OMNIVORES 
(B).CARNIVORES 
(C).OMNIVORES 
(D).ALL HAVE SAME NUMBER

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IF YOU HAVE AN ANSWER PLEASE RPLY

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## Amna Amir (Apr 1, 2013)

CHOCLATE said:


> The acidity of chyme stimulates
> (a).pancreatic cell
> (b).liver cell
> (c).duodenal cell
> ...


1.d
2.a


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## CHOCLATE (Jul 5, 2013)

as carnivores eat flesh of animals so they have maximum number of enzymes ...... predators usually eat live prey...to digest it they have more enzymes

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i m a bit confuse about it ........


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## adnan ahmed (Jul 18, 2013)

B is correct

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B IS CORRECT


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## CHOCLATE (Jul 5, 2013)

yes b is right one according to reason i have mentioned above..................


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## Amna Amir (Apr 1, 2013)

the bile juice is 
a) acidic
b) basic
c) neutral
d) both a or b


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## CHOCLATE (Jul 5, 2013)

I am not sure about but i guess that bile juice is basic because it contains no enzymes........ Bile salts emulsify fats .........sodium hydrogen carbonate present in bile neutralize stomach" acid and create alkaline medium ..........make fat soluble vitamins to water soluble for absorption by intestine ........................ So due to its basic nature ...neutralize acidic MEDIA to maintain ph.........am i right??????????


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## Amna Amir (Apr 1, 2013)

CHOCLATE said:


> I am not sure about but i guess that bile juice is basic because it contains no enzymes........ Bile salts emulsify fats .........sodium hydrogen carbonate present in bile neutralize stomach" acid and create alkaline medium ..........make fat soluble vitamins to water soluble for absorption by intestine ........................ So due to its basic nature ...neutralize acidic MEDIA to maintain ph.........am i right??????????



•Bile contains bile acids, which are critical for digestion and absorption of fats and fat-soluble vitamins in the small intestine.
Emulsification of lipid aggregates: Bile acids have detergent action on particles of dietary fat which causes fat globules to break down or be emulsified into minute, microscopic droplets. 

for detail visit this site
biology.about.com/library/organs/bldigestliver3.htm


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## CHOCLATE (Jul 5, 2013)

but in our syllabus textbook just bile salts and pigments are mentioned ............no function of bile acid has been mention...........

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and for uhs we have just stick to syllabus.........


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## CHOCLATE (Jul 5, 2013)

so bile juice is acidic,basic or neutral?????????????


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## Mariamumtaz (Jun 26, 2013)

how to prepare mcat english grammer please help..


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## Amna Amir (Apr 1, 2013)

CHOCLATE said:


> so bile juice is acidic,basic or neutral?????????????


finally it's 'Alkaline' ... I confirmed it by my Sir


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## CHOCLATE (Jul 5, 2013)

reason which i have mentioned above was also told by my mam ..........yes it is basic


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## Mariamumtaz (Jun 26, 2013)

hi friends...i am posting here some physics questions..please help me solving them..and give reason too..it'll be a great help for me.
Q1
light of frequency 6 into 10*14 hz pases through a diffraction grating with 4 into 10*3 lines/cm.wavelngth of ligth used is 
2 into 10*-9m
5 into 10*-7m
5 into 10*-9m
6 into 10*14m



Q2 A plane polarized light of intensity I is falls normally on thin piece of polaroid.if transmitted light has intensity I/4 then angle of polarization axis of polaroid will be
22.5 degree
60 deg
30 deg
95 deg


Q3 two waves have amplitude in ratio 5:1 produces intrfernc the ratio of maximum to minimum intensity is 
25:1
6:4
9:4
3:2



Q4 time period of simple pendulum inside stationary lift is T.If lift starts moving upward with acceleration g/3 then period will be
T/3
3T
sq.root 3sq.rootT/sq.root2
sq.root 3 T/3(no sq.root on T)




Q5 in what time aftr its motion will begin acc. to equation x=7sin0.5pi t(time) when move from mean to maximum displacemnt.
1second
1/2s
1/4s
1/6s




Q6 what is 273k on celcius scale of temperature
-o.o15
-0.15
0
273


Q7 An ideal carnot engine has efficincy 40%receivs at 500k.if efficiency is 50% the intake temp for same exhaust temp is
600k
900k
700k
800k



Q8 oxygen molecule in earth atmosphere have root mean sq speed 500 m pr s.if relative molecular mass of 02 and helium is 32 ans 4 then approximate rms speed of helium in atmosphere will be
180
1400
1000
2000

THESE QUESTIONS ARE FROM WAVES LIGHT AND IDEAL GAS THERMODYNAMICS..


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## Amna Amir (Apr 1, 2013)

MastahRiz said:


> *[Question #2]*
> 
> Which of the types of RNA is the smallest?
> 
> ...


its tRNA


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## CHOCLATE (Jul 5, 2013)

r-RNA is smallest type of RNA not t-RNA........


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## Mariamumtaz (Jun 26, 2013)

yes rNA is smallest not tRNA..


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## maryyum (Aug 19, 2013)

1. The characters common and different in protests and other kingdoms except monera
a) Eukaryotic cell and blastula b) Prokaryotic cell and no blastula
c) Eukaryotic cell and no embryo d) Prokaryotic cell and no embryo
2. Which is not true for giant amoeba?
a) Most Primitive of all eukaryote-like forms
b) Obtains energy from methanogenic bacteria
c) Contains all eukaryotic organelle
d) Contribute to degrandation of organic molecule
3. All of the following are parasitic protozoans except
a) Plasmodium b) Trypansoma
c) Trichonymphas d) Entamoeba histolytica
4. The vector in case of Trypanosoma
a) Mosquito b) Housefly c) Tsetse fly d) None of these
5. Choanoflagellates resemble to collar cells in
a) Sponges b) Cnidarians
c) Ciliates d) Actinopods


answer the following questions if you can .


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## CHOCLATE (Jul 5, 2013)

out of syllabus..........


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## maryyum (Aug 19, 2013)

that's the main problem  we should also go through the other topics , not mentioned in UHS syllabus but mentioned in our books.:thumbsup:

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*Trigger of hormones to heat production is:*
a. Shivering thermogenesis b. Thermogenesis
c. Non-Shivering thermogenesis d. All of them


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## Mariamumtaz (Jun 26, 2013)

*option c*


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## maryyum (Aug 19, 2013)

I wanna ask a question to all dear medical form students . The words ask ( for meanings or synonyms) in part 1 and part 4 of UHS English entry test,are these words necessarily from essential word power given in UHS syllabus ??????????? :?:?


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## Mariamumtaz (Jun 26, 2013)

yup....marryam


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## jamal (Feb 15, 2012)

Yes in previous year they did so.


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## maryyum (Aug 19, 2013)

thank you very much


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## maryyum (Aug 19, 2013)

what is meaning of CONTRADOW ?is this word really exists ???:: I'm really confused:? ..please help


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## rosequartz (Jul 24, 2012)

maryyum said:


> what is meaning of CONTRADOW ?is this word really exists ???:: I'm really confused:? ..please help


An extremely late reply, but contradow is neither a word nor is it in the MCAT vocabulary list. 
Although, contravene, contrive, comatose & contra are.


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## M Amin Amjad (Jul 6, 2013)

What type of alpha particles produce ions in a GAS when they passed through it from radioactive elements
1) Anions
2) Cations
3) Both
4) Neither cation nor Anion produced
Give answer it with Reason.

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How gama rays convert atoms of gas particles into ions? What types of gama rays produce ions in a gas?
As a short question give answer of this question and explain it with reason.


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## goldstandard_mcat (Mar 4, 2014)

Can I also contribute MCAT questions in this link? For example, this one:
A student throws a rock at a 60° angle over a lake. The rock leaves his hand at a velocity of 20 m/s. How far away from the student will the rock shadow appear on the ground after 1 second, assuming the shadow projects straight down from the rock?
A) 5 m
B) 7 m
C) 10 m
D) 12 m


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## goldstandard_mcat (Mar 4, 2014)

[FONT=&quot]The answer is C. Because the question asks for the distance between the rock’sshadow and the student, the distance will be a horizontal distance. The horizontalvelocity of the rock is given by v[SUB]x[/SUB]= v•cosθ= v•cos60[SUP]o[/SUP]= v(1/2). Thus v[SUB]x[/SUB]=10 m/s. So, distance x is given by x= (v[SUB]x[/SUB])(t)=10 m/s (1s)= 10 m.[/FONT][FONT=&quot][/FONT]


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## goldstandard_mcat (Mar 4, 2014)

Question 2:
Suppose that an object is lifted vertically each of the distances shown below at constant speed, in the time periods given. 
Case I: 2m; 2 sec 
Case 11: 4m; 1 sec 
In which case is the average power employed greater? 
A) case 1
B) case 2
C) Same in both cases
D) cannot be determined from the information given


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## ayesha zahid (Jun 1, 2014)

I am pre medical student and I have join this group to get some help about mcat entry test...


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## goldstandard_mcat (Mar 4, 2014)

[h=4]In eukaryotic cells, which of the following is a site of cellular respiration?[/h]A) Lysosomes
B) ATP
C) Ribosomes
D) Mitochondria


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## rosequartz (Jul 24, 2012)

M Amin Amjad said:


> What type of alpha particles produce ions in a GAS when they passed through it from radioactive elements
> 1) Anions
> 2) Cations
> 3) Both
> ...


B. Cation. Alpha particle is He+, which is a cation. 



goldstandard_mcat said:


> Question 2:
> Suppose that an object is lifted vertically each of the distances shown below at constant speed, in the time periods given.
> Case I: 2m; 2 sec
> Case 11: 4m; 1 sec
> ...


B. Case 2. 
Power = Work done/time taken. Putting values in equation, case 2 has greater average power. 



goldstandard_mcat said:


> [h=4]In eukaryotic cells, which of the following is a site of cellular respiration?[/h]A) Lysosomes
> B) ATP
> C) Ribosomes
> D) Mitochondria


D. Mitochondria. Because ATP is produced by cellular respiration, lysosomes help with digestion and ribosomes carry out protein synthesis. 

Can you post more questions? That would be great!


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## goldstandard_mcat (Mar 4, 2014)

Which (see image) of the following acids have the largest pKa?
See image here

a. A
b. B
c. C
d. D 

Correct Answer: A 
Recall that pKa = -log Ka so their relative values, because of the negative sign in the equation, are always opposite to each other. Thus in an acid base equilibrium, AH  A- + H+, the largest pKa value is associated with the weakest acid. The unhalogenated carboxylic acid A is the weakest acid (acetic acid is the IUPACname; ethanoic acid is the systematic way to name it). In the other cases, the electron withdrawing halogen substituent stabilize the carboxylate conjugate base (anion) making the parent acid more acidic.

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Embryonic mesoderm in humans develops into which of the following structures?

A. Liver and pancreas
B. Brain
C. Lining of the respiratory tract
D. Skeleton

ANSWER: D
The mesoderm develops into muscle and connective tissue which includes blood and bone (skeleton!), as well as circulatory, reproductive and excretory organs. The ectoderm produces the epidermis and the nervous system including the brain. The endoderm will become the epithelial lining of the respiratory tract, and the digestive tract including the glands of the accessory organs (i.e. the liver and pancreas). The stage of the embryo where the 3 primary germ layers first develop is called the ‘gastrula’.


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## goldstandard_mcat (Mar 4, 2014)

If the sum of all the forces acting on a moving object is zero, the object will:

A. decelerate and stop.
B. accelerate uniformly.
C. change the direction of its motion.
D. continue moving with constant velocity.


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## goldstandard_mcat (Mar 4, 2014)

All of the following quantities are vectors EXCEPT one. Which one is the EXCEPTION? 

A. Electric current
B. Magnetic field
C. Electric force
D. Electric potential

ANSWER: D
Fields are vectors because they cause forces, and force is a vector. Current is a vector because charge can flow in either direction in a wire. However, electric potential is related to potential energy (PE = qV ), and all forms of energy are scalar quantities.

For more MCAT2015 sample questions, click here


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## rosequartz (Jul 24, 2012)

goldstandard_mcat said:


> If the sum of all the forces acting on a moving object is zero, the object will:
> 
> A. decelerate and stop.
> B. accelerate uniformly.
> ...


Option D as per Newton's laws of motion.


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## goldstandard_mcat (Mar 4, 2014)

rosequartz said:


> Option D as per Newton's laws of motion.


You're right 

Answer: D
Explanation: For something to change direction or accelerate there must be a net force acting on it (Newton’s 2[SUP]nd[/SUP] Law). 
Also, Newton’s 1[SUP]st[/SUP] Law states that an object in motion will stay in motion at constant velocity (a form of inertia) unless acted upon by a net (an unbalanced) force.


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## goldstandard_mcat (Mar 4, 2014)

Oxidative phosphorylation is best described as:

A. the process in which ATP is formed as electrons are transferred fromelectron carriers to oxygen.
B. the process to repay the oxygen debt.
C. the process in which ATP is formed as pyruvate is convertedinto acetyl CoA.
D. the process in which ATP is formed as acetyl CoA is completely oxidized tocarbon dioxide.


*Correct answer: *A
*
Explanation:*
Oxidative phosphorylation is defined by A; B may be true but it is aninadequate description of oxidative phosphorylation; C describes theintermediate step between glycolysis and the Krebs cycle; D describes the Krebscycle.


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## goldstandard_mcat (Mar 4, 2014)

Choose the molecule that has the correct dipole orientation.
See image here 

Correct Answer: B
The polarization of a bond is determined by the relative electronegativity of each particular atom. As Cl is more electronegative than a hydrogen atom, so the dipole moment points towards the Cl atom along the H-Cl bond. As a good memory guide, from your physics review, you would know that an electric field line always points away from a positive charge.


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## hafsanoor (Jun 6, 2018)

B. tRNA


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