OAT Online Practice Questions and Answers

Correct Answer: A

Sound travels much faster through helium than through air. Generally, the speed of sound can be calculated by speed = (k ?P / ), where k is the index of specific heats, P is pressure and is density. Since helium has a much lower density, it would have a higher speed.

Correct Answer: D

It will cost $88 to paint an area of 90 square feet (9 ft × 10 ft). The new wall has 630 square feet (21 ft × 30 ft). Thus, the new area is 7x bigger (630 square feet / 90 square feet = 7), and thus, 7x more expensive.

7 × $88 = $616

Correct Answer: D

3 1/4 × 8/18 = 13/4 × 8/18 = 104/72 = 13/9 = 1 4/9.

Correct Answer: D

Transformation is the definition of picking up free DNA from other bacteria that died. Conjugation is the transfer of DNA from a one cell to another via the pilus. Transduction is the use of bacteriophages (virus) to transfer DNA from one bacteria cell to another via infection.

Correct Answer: E

This is a simple monohybrid cross. Assume `R' for the dominant red hair and `r' for the recessive black hair.

From this cross, it is obvious to see all the offspring will have red hair.

Correct Answer: E

All of the answer choices are involved in the clotting process. Thromboplastin aids in the conversion of prothrombin to thrombin, which then aids in the conversion of fibrinogen to fibrin.

Correct Answer: A

Monocots differ from dicots in that they have one cotyledon, or embryonic leaf in their embryos. They also have parallel veination, fibrous roots, petals in multiples of three, and a random arrangement of vascular bundles in their stems.

Correct Answer: D

Answer choices [Adding extra NH3(g)], [Removing N2(g)], [Removing H2(g)] all cause the reaction to shift to the left (towards the reactants). Increasing the pressure shifts the reaction towards the side with the fewer molecules (in this case, the product side). Thus, increasing the pressure shifts the reaction to the right to restore equilibrium.

Correct Answer: D

In general, triple bonds > double bonds > single bonds in bond energies. CN is linked via a triple bond: C N

Correct Answer: A

Begin by looking at the reactant side and noting down the number of mass number and protons (235 and 92 respectively). These numbers have to match the total numbers on the product side. The 2 alpha-decay and 1 beta-decay give you a mass of 8, which means it is 227 short of the mass number in the reactants. They also produce a (2 + 2 − 1 = 3) number of protons, 89 short of balancing the reactant number of protons. Thus, your missing daughter nuclei will have a mass of 227 and 89 protons. Looking at a periodic table, the atom Ac has 89 protons.