Science TEAS Practice Test

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: 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: The correct answer is A: The human body has evolved to become more resilient to its environment. This statement is not likely to have contributed to the longer life expectancy in the 21st century. Evolution occurs over long periods of time, not within a span of a few hundred years. Advances in medical technology and treatments (B), higher standards of basic cleanliness (C), and the creation of vaccines (D) have all played significant roles in increasing life expectancy by preventing and treating diseases, improving overall health, and reducing mortality rates. These factors are directly linked to improvements in healthcare and sanitation practices, which have had a tangible impact on life expectancy.

Correct Answer: D

Rationale: The correct answer is D: Plasma cells. Plasma cells are a type of white blood cell that produces and secretes antibodies, which are essential for the immune response. Plasma cells are specifically designed to produce antibodies to fight off infections. Bacterial cells (choice A) and viral cells (choice B) do not secrete antibodies as they are pathogens. Lymph cells (choice C) are a general term for various types of white blood cells, including plasma cells, but not all lymph cells secrete antibodies. Plasma cells, on the other hand, are specialized for antibody production, making choice D the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Quantitative data is more accurate than qualitative data. This statement is false because the accuracy of data depends on the research question and the methodology used, not on whether it is qualitative or quantitative. Both types of data have their strengths and limitations. Quantitative data is numerical and lends itself to statistical analysis, but it can lack depth and context. Qualitative data, on the other hand, provides rich insights into perspectives and behavior but may be subjective. Therefore, it is essential to use both types of data in scientific research to gain a comprehensive understanding of a research problem.