Science TEAS Practice Test

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: 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: B

Rationale: The correct answer is B: A gene. A gene is the smallest unit that can encode for a trait because it is a specific sequence of nucleotides in the DNA that provides instructions for a particular trait or function. Genes determine our physical characteristics and traits. A codon (choice A) is a sequence of three nucleotides that code for a specific amino acid in protein synthesis, not a complete trait. A nucleotide (choice C) is the basic building block of DNA, but it is not capable of encoding for a trait on its own. A chromosome (choice D) is made up of DNA and contains multiple genes, so it is not the smallest unit that can encode for a trait.

Correct Answer: C

Rationale: The correct answer is C: The pancreas. The pancreas functions as both an endocrine and exocrine gland. It secretes digestive enzymes (exocrine function) into the small intestine and produces hormones such as insulin and glucagon (endocrine function). This dual role allows the pancreas to regulate both digestion and blood sugar levels. Incorrect Answers: A: The kidney - Functions mainly in filtration and regulation of fluid balance, not as an endocrine/exocrine gland. B: The spleen - Primarily involved in immune function and blood filtration, not as an endocrine/exocrine gland. D: The stomach - Secretes digestive enzymes, but does not have a significant endocrine function like the pancreas.

Correct Answer: D

Rationale: Step-by-step rationale: 1. Meiosis involves two rounds of cell division. 2. In meiosis I, homologous chromosomes separate, resulting in haploid daughter cells with half the number of chromosomes. 3. In meiosis II, sister chromatids separate, resulting in four haploid daughter cells. 4. Since humans have 46 chromosomes in their somatic cells, each resulting cell after meiosis will contain 23 chromosomes. Summary: A: 96 is incorrect as it is a doubled diploid number. B: 54 is incorrect as it is not the correct halving of the diploid human chromosome number. C: 46 is incorrect as it represents the original number of chromosomes in a human somatic cell, not the resulting number after meiosis.