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: A

Rationale: Failed to generate a rationale after 5 retries.

Correct Answer: B

Rationale: To calculate the grams of CaCO3 needed, we first find the molar mass of CaCO3: 40.07 (Ca) + 12.01 (C) + (15.99 x 3) (O) = 100.08 g/mol. Next, use the formula: grams = moles x molar mass. Moles = 0.35 M x 0.6 L = 0.21 moles. Therefore, grams = 0.21 moles x 100.08 g/mol = 21.02 g. Hence, the correct answer is B: 19.7 g. Other choices are incorrect due to miscalculation or incorrect conversion.

Correct Answer: A

Rationale: The correct answer is A: Phenotype. Phenotype refers to the physical and visible expression of a genetic trait. It includes observable characteristics like eye color, height, and hair texture. This is different from genotype, which represents the genetic makeup of an organism. Allele refers to different forms of a gene, and gamete is a reproductive cell. Thus, in this context, phenotype best describes the physical manifestation of a genetic trait, making it the correct answer.

Correct Answer: A

Rationale: The correct answer is A: Dense bone. Dense bone is not one of the major types of bones in the human body. Long bones, short bones, and irregular bones are the three major types. Long bones are characterized by being longer than they are wide, like the femur. Short bones are cube-shaped, like the carpals in the wrist. Irregular bones have complex shapes and are typically found in the spine and face. Dense bone is not a separate category but rather a classification based on the density of bone tissue. It refers to the outer layer of compact bone found in all bone types. Therefore, A is the correct answer because dense bone is not a distinct major type of bone in the human body.