## OAT Biology Practice Test Answers

1:A Long term energy storage in animals takes the form of fat. Animals also store energy as glycogen, and plants store energy as starch. , but these substances are for shorter-term use. Fats are a good storage form for chemical energy because fatty acids bond to glycerol in a condensation reaction to form fats (triglycerides). This reaction, which releases water, allows for the compacting of high-energy fatty acids in a concentrated form.

2:D When Ca^{2+} channels open, calcium enters the axon terminal and causes synaptic vesicles to release neurotransmitter into the synaptic cleft.

3:B The bonds between hydrogen and oxygen in water involve shared electrons and are therefore covalent. But the electrons are shared unequally because oxygen is more electronegative than hydrogen, so the shared electrons are more attracted to oxygen. Hydrogen â€“ oxygen bonding *between *water molecules is an example of hydrogen bonding.

4:C According to Hardy-Weinberg equilibrium,

*p*+

*q*= 1 and

*p*+ 2

^{2}*pq*+

*q*= 1. In this scenario,

^{2}*q*= 0.25, so

^{2}*q*= 0.5.

*p*must also be 0.5.

5:D A lineage map describes the fates of cells in the early embryo: in other words, it tells which germ layer different cells will occupy. In some small organisms such as the nematode *Caenorhabditis elegans*, all of the adult cells can be traced back to the egg. A lineage map is not a mechanism of embryo development, but rather a tool for describing it.

## OAT General Chemistry Practice Test Answers

1:B The ideal gas law PV=nRT is rearranged to solve for V, and we get V = nRT/P. R is the gas constant, 0.08206 L atm/mol K, and the Celsius temperature must be converted to Kelvin, by adding 273 to 25^{o}C to obtain 298 K. The pressure must be converted to atmospheres, which 101 kPa is essentially 1 atm (0.9967 atm). Plugging the numbers into the equation we get V = 1000 mol (0.08206 L atm/mol K)(298 K)/1 atm, which gives V = 24,453 L. A liter is a cubic decimeter (dm^{3}) and when converted gives V = 24.5 m^{3}.

2:B Since both the volume and the temperature remain fixed, the only variable that changes is the number of moles of particles. Because there are now 3 times the number of particles as there were originally, the pressure must increase proportionately and so the pressure must be 3 atm.

3:C Normality refers to the concentration of acid equivalents (H^{+} ions), not the concentration of the solute. 100 g of phosphoric acid has a MW of 98 g/mol. So, 100g/98 g/mol = 1.02 moles of phosphoric acid are in solution. The total volume of the solution is 0.4 L, so the molarity of the solution is 1.02 mol/0.4 L = 2.55 M. Since there are three acid equivalents for every mole of phosphoric acid, the normality is 3 x 2.55 = 7.65 N.

4:D 100 mL of a 0.1 M solution of NaOH contains 0.01 moles of NaOH. That means 0.01 moles of acid are required to completely neutralize the solution. The MW of sulfuric acid is 98, so 0.98 g of sulfuric acid is 0.01 mole. But since sulfuric acid has two equivalents of acid per mole, only 0.005 mole of the acid is required or 0.49 g.

5:B Hybrid orbitals arrange themselves to be as far from each other as possible. An sp^{2} atom has three hybrid orbitals, so they arrange themselves to be trigonal planar, with 120 ° between the bonds.

## OAT Organic Chemistry Practice Test Answers

1:B The ideal gas law PV=nRT is rearranged to solve for V, and we get V = nRT/P. R is the gas constant, 0.08206 L atm/mol K, and the Celsius temperature must be converted to Kelvin, by adding 273 to 25^{o}C to obtain 298 K. The pressure must be converted to atmospheres, which 101 kPa is essentially 1 atm (0.9967 atm). Plugging the numbers into the equation we get V = 1000 mol (0.08206 L atm/mol K)(298 K)/1 atm, which gives V = 24,453 L. A liter is a cubic decimeter (dm^{3}) and when converted gives V = 24.5 m^{3}.

2:B Since both the volume and the temperature remain fixed, the only variable that changes is the number of moles of particles. Because there are now 3 times the number of particles as there were originally, the pressure must increase proportionately and so the pressure must be 3 atm.

3:C Normality refers to the concentration of acid equivalents (H^{+} ions), not the concentration of the solute. 100 g of phosphoric acid has a MW of 98 g/mol. So, 100g/98 g/mol = 1.02 moles of phosphoric acid are in solution. The total volume of the solution is 0.4 L, so the molarity of the solution is 1.02 mol/0.4 L = 2.55 M. Since there are three acid equivalents for every mole of phosphoric acid, the normality is 3 x 2.55 = 7.65 N.

4:D 100 mL of a 0.1 M solution of NaOH contains 0.01 moles of NaOH. That means 0.01 moles of acid are required to completely neutralize the solution. The MW of sulfuric acid is 98, so 0.98 g of sulfuric acid is 0.01 mole. But since sulfuric acid has two equivalents of acid per mole, only 0.005 mole of the acid is required or 0.49 g.

5:B Hybrid orbitals arrange themselves to be as far from each other as possible. An sp^{2} atom has three hybrid orbitals, so they arrange themselves to be trigonal planar, with 120 ° between the bonds.

## OAT Physics Practice Test Answers

1:D The weight of the art is 200 kg x 9.8 m/s^{2 }= 1960 N. This is the total force pulling DOWN on the wires. However, the tension acts along a 30° angle, and the vertical force is T sinÎ¸. However there are two ends to the wire, which splits the tension, meaning the weight is spread across 2T sinÎ¸. So 2T sinÎ¸ = w. Therefore, T = Â½ x 1960 N / sin(40) = 1524 N. Note: There’s also a horizontal component to the tension forces, each expressed as T cosÎ¸. The net force of the left and right tensions is zero. Answer A is calculated using the Cos(40) instead of Sin(40).

2:A In a closed system (when you ignore outside interactions), the total momentum is constant and conserved. The total energy would also be conserved, although not the sum of the potential and kinetic energy. Some of the energy from the collision would be turned into thermal energy (heat) for example. Nor is the total velocity conserved, even though the velocity is a component of the momentum, since the momentum also depends on the mass of the cars. The impulse is a force over time that causes the momentum of a body to change. It doesn’t make sense to think of impulse as conserved, since it’s not necessarily constant throughout a collision.

3:B The answer can be determined because the rate of acceleration is uniform. Since the acceleration is 5 m/s^{2}, the velocity increases by 5 m/s every second. If it starts at 20 m/s, after 1 second it will be going 25 m/s. After another second it will be going 30 m/s, so the total time is 2 seconds. You can also calculate this time by using the average speed. Since the object undergoes uniform acceleration, the average speed is 25 m/s. Using the distance traveled, the same result is obtained. t = d / v = 50 meters / 25 m/s = 2 seconds.

4:A Newton’s first law (inertia) says an object in motion stays in motion, and an object at rest stays at rest, unless external forces act on them. I is an excellent demonstration because it shows the ball at rest and in motion. At rest, the ball stays at rest until a force acts on it. When the ball is moving, there is no force acting on the ball in the direction of motion. Thus, the natural state of the ball is to be at rest or moving with a constant speed. Ans. C is not a good demonstration because the force of friction is what makes it hard to move the heavy object. Ans B is a good demonstration of equilibrium and friction. Ans D, running a current through wires, has nothing to do with Newton’s first law.

5:D There will be a gravitational force of attraction between the two spheres determined by the universal constant of gravity, the distance between the spheres, and the mass of the spheres. Since both objects are affected by this force (remember, Newton’s 3rd law says the force needs to be equal and opposite), both objects will experience a slight acceleration and start moving towards each other a tiny amount (when we ignore friction). Using F = ma, you know that the less massive sphere will experience a larger acceleration than the more massive one.

## OAT Quantitative Reasoning Practice Test Answers

1:C The total distance traveled was 8+ 3.6 = 11.6 miles. The first 1/5^{th} of a mile is charged at the

higher rate. Since 1/5^{th} = 0.2, the remainder of the trip is 11.4 miles. Thus the fare for the distance traveled is computed as . To this the charge for waiting time must be added, which is simply 9 x 20cents = 180cents = $1.80. Finally, add the two charges, $91 + $1.80 = $92.80.

2:C Rearranging the equation gives

which is equivalent to

or

and solving for *x*,

3:A From the starting expression, compute:

B. â€“ 3x + 6 ≠

C. Â ≠

D. Â ≠

4:D To multiply two binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last. When multiplying each pair of terms, remember to multiply the coefficients, then add the exponents of each separate variable. So the product of the First terms is

The product of the Outside terms is

The product of the Inside terms is

The product of the Last terms is

The final answer is simply the sum of these four products.

5:C Divide the mg the child should receive by the number of mg in 0.8 ml to determine how many 0.8 ml doses the child should receive: 240 Ã· 80 = 3. Multiply the number of doses by 0.8 to determine how many ml the child

should receive: 3 X 0.8 = 2.4 ml

## OAT Reading Comprehension Practice Test Answers

1:C

2:A

3:D

4:C

5:B