Science TEAS Practice Test

Correct Answer: B

Rationale: The correct answer is B. If an organism is AB, it means they have alleles A and B. In gametes, each gamete carries only one allele. Therefore, gametes with AA are not possible as they lack the B allele. Gametes with AB are possible since they can carry either A or B allele. Gametes with BB are not possible as they lack the A allele. Gametes with AB are possible as they can carry either A or B allele.

Correct Answer: A

Rationale: Step-by-step rationale for answer A: 1. Oxygenated blood from the lungs enters the left atrium. 2. It then passes through the mitral valve into the left ventricle. 3. Upon contraction, it is pumped into the aorta. 4. The oxygenated blood is then dispersed to tissues through a network of arteries and capillaries. Summary of why other choices are incorrect: B: Incorrect because oxygenated blood does not go to the right side of the heart. C: Incorrect because there is no direct connection between the left atrium and the right aorta. D: Incorrect because there is no septal valve and oxygenated blood is not stored in the left ventricle.

Correct Answer: A

Rationale: The correct answer is A: Condensation is the process of changing from a gas to a liquid. This is because condensation occurs when a gas loses heat energy and transitions into a liquid state. The gas molecules slow down and come closer together, forming liquid droplets. Explanation: 1. In condensation, gas molecules lose energy and move closer together. 2. This causes the gas to transition into a liquid state. 3. The process of condensation is commonly observed in everyday situations like when water vapor in the air cools and forms dew on a cold surface. Summary: B: Changing from a liquid to a gas is called evaporation, not condensation. C: Changing from a solid to a liquid is called melting, not condensation. D: Changing from a solid to a gas is called sublimation, not condensation.

Correct Answer: C

Rationale: The correct answer is C: Covalent. In DNA, sugar and phosphate molecules are joined together by covalent bonds. Covalent bonds involve sharing of electrons between atoms, providing a strong and stable connection. This type of bond is essential for the structural integrity of the DNA molecule. A: Hydrogen bonds are important in DNA structure, but they connect the nitrogenous bases, not sugar and phosphate. B: Ionic bonds involve the transfer of electrons between atoms, not sharing, and are not typically involved in connecting sugar and phosphate in DNA. D: "Overt" is not a recognized type of chemical bond; it is an incorrect distractor.

Correct Answer: C

Rationale: The correct answer is C: White blood cells. White blood cells, specifically lymphocytes, are responsible for producing antibodies as part of the immune response. Platelets are involved in blood clotting, not antibody production. Red blood cells carry oxygen and do not play a role in immune responses. Plasma cells are a type of white blood cell that produces antibodies, but they are a specialized subset of white blood cells and not the main component responsible for antibody production.