ATI TEAS Science Questions

Correct Answer: B

Rationale: The main function of the skeletal system is to provide structural support for the body, protect internal organs, facilitate movement, and produce blood cells in the bone marrow. Choice A, 'To regulate blood pressure,' is incorrect as blood pressure regulation is primarily controlled by the circulatory and endocrine systems. Choice C, 'To produce hormones,' is incorrect as hormone production is mainly carried out by the endocrine system. Choice D, 'To fight infection,' is incorrect as the immune system is responsible for fighting infections, not the skeletal system.

Correct Answer: B

Rationale: The correct answer is B: Proteins. Proteins are the only macromolecules that always contain nitrogen in their amino acid structure. Nitrogen is a key element found in the amino groups of amino acids, which are the building blocks of proteins. Fatty acids (Choice A), lipids (Choice C), and carbohydrates (Choice D) do not always contain nitrogen in their structure. Fatty acids are composed of long hydrocarbon chains and do not contain nitrogen. Lipids consist mainly of carbon, hydrogen, and oxygen, with some classes of lipids containing phosphorus but not nitrogen. Carbohydrates are made up of carbon, hydrogen, and oxygen, forming structures like sugars and starches, but they do not contain nitrogen.

Correct Answer: A

Rationale: Totipotent stem cells have the unique ability to differentiate into any cell type in the human body and can generate a complete organism. They are considered the most versatile type of stem cells, capable of developing into all cell types, including extraembryonic tissues. Choice A, Totipotent stem cells, is the correct answer as it specifically describes stem cells with the broadest differentiation potential. Choice B, Multipotent stem cells, refers to stem cells that can differentiate into a limited range of cell types. Choice C, Pluripotent stem cells, can give rise to almost all cell types, but not the complete organism like totipotent stem cells. Choice D, Hematopoietic stem cells, are a type of multipotent stem cells that give rise to various blood cell types, but do not have the same broad differentiation potential as totipotent stem cells.

Correct Answer: B

Rationale: The correct answer is B: mRNA. Messenger RNA (mRNA) is responsible for carrying the genetic information copied from DNA to the ribosomes for protein synthesis. mRNA serves as a temporary copy of the genetic instructions stored in DNA and acts as a messenger between the nucleus and ribosomes in the cytoplasm where protein synthesis occurs. While rRNA (ribosomal RNA) and tRNA (transfer RNA) play essential roles in the process of translation at the ribosomes, mRNA is the nucleic acid directly involved in carrying the genetic code for protein synthesis. Therefore, choices A, C, and D are incorrect as DNA is the original genetic material, rRNA is a component of the ribosomes, and tRNA carries amino acids during protein synthesis, respectively.

Correct Answer: C

Rationale: The correct answer is C: Duodenum, jejunum, ileum. The small intestine is divided into three regions: the duodenum, jejunum, and ileum. The duodenum is the initial segment where most chemical digestion takes place. The jejunum and ileum follow the duodenum and are primarily responsible for nutrient absorption. Choice A is incorrect because the order is incorrect. Choice B is incorrect because the cecum is part of the large intestine, not the small intestine. Choice D is incorrect because the colon is part of the large intestine, not the small intestine.