from which of the following germ layers does the nervous system develop

ATI TEAS 7

Practice TEAS Science Test

1. From which of the following germ layers does the nervous system develop?

A. Ectoderm
B. Endoderm
C. Gastroderm
D. Mesoderm

Correct answer: A

Rationale: The correct answer is A: Ectoderm. The nervous system develops from the ectoderm, which is the outermost of the three germ layers. The ectoderm gives rise to structures such as the skin, hair, nails, and the entire nervous system. Choices B, C, and D are incorrect because the endoderm gives rise to the lining of the gut and associated organs, the gastroderm is not a recognized germ layer, and the mesoderm forms structures like muscles, bones, blood, and the circulatory system, but not the nervous system.

2. When an atom gains or loses electrons, it becomes a(n):

A. Molecule
B. Isotope
C. Ion
D. Compound

Correct answer: C

Rationale: When an atom gains or loses electrons, it becomes an ion. Gaining or losing electrons alters the atom's electron count and charge, creating a positively or negatively charged ion. A molecule is formed when two or more atoms are chemically bonded. An isotope is a variation of an element with a different number of neutrons. A compound consists of two or more different elements chemically bonded together.

3. Which of the following are the reproductive cells produced by meiosis?

A. Genes
B. Alleles
C. Chromatids
D. Gametes

Correct answer: D

Rationale: The correct answer is D. Gametes are the reproductive cells produced by meiosis. Meiosis is the cell division process that results in the formation of gametes, which are sperm cells in males and egg cells in females. Genes (A), alleles (B), and chromatids (C) are not the reproductive cells produced by meiosis. Genes are units of heredity, alleles are different forms of a gene, and chromatids are duplicated chromosomes involved in cell division.

4. What is the primary function of the nervous system?

A. To produce hormones
B. To transmit electrical impulses
C. To carry oxygen
D. To transport nutrients

Correct answer: B

Rationale: The correct answer is B: To transmit electrical impulses. The primary function of the nervous system is to transmit electrical impulses and coordinate body activities. While hormones are produced by the endocrine system, not the nervous system, oxygen transportation is mainly carried out by the respiratory system, and nutrient transport is primarily the role of the circulatory system. Therefore, choices A, C, and D are incorrect as they do not align with the primary function of the nervous system.

5. What type of immunity is acquired through vaccination?

A. Passive natural immunity
B. Active natural immunity
C. Active artificial immunity
D. Passive artificial immunity

Correct answer: C

Rationale: The correct answer is C, Active artificial immunity. Vaccination introduces a weakened or inactive form of the pathogen to stimulate the immune system, leading to the development of immunity. Active artificial immunity is the result of deliberate exposure to an antigen, such as through vaccination, to produce an immune response. Passive immunity, like receiving pre-formed antibodies, does not involve the immune system's activation. Natural immunity is typically acquired through exposure to the pathogen itself, not through vaccination.