TEAS 7 science study guide free

Correct Answer: A

Rationale: The correct answer is A: Myelin sheath. The myelin sheath is a fatty layer that surrounds and insulates some nerve fibers, facilitating the rapid transmission of signals along the nerve fibers. Choices B, C, and D (Dura mater, Pia mater, and Arachnoid mater) are layers of the meninges, protective membranes that surround the brain and spinal cord. The primary function of the meninges is to protect and support the central nervous system, not to insulate nerve fibers for signal transmission.

Correct Answer: B

Rationale: Sebaceous glands are responsible for secreting an oily substance called sebum, not sweat, cerumen, or mucus. Sebum plays a vital role in lubricating and waterproofing the skin and hair, preventing them from drying out. Sweat glands produce sweat to regulate body temperature. Cerumen is the medical term for earwax, produced by ceruminous glands in the ear canal, while mucus is a slimy substance that protects and lubricates body tissues. Therefore, the correct answer is B: Sebum, as it is the oily substance secreted by sebaceous glands.

Correct Answer: B

Rationale: The correct answer is the ovaries. Ovaries are the primary reproductive organs in females responsible for producing eggs (ova) through a process known as oogenesis. Ova are released from the ovaries during ovulation and can be fertilized by sperm in the fallopian tubes. The uterus is where a fertilized egg implants and develops into a fetus, while the vagina serves as the birth canal and a site for sexual intercourse. Fallopian tubes are responsible for transporting eggs from the ovaries to the uterus and are the site where fertilization typically occurs. Therefore, while important for the reproductive process, the fallopian tubes do not produce eggs.

Correct Answer: B

Rationale: The correct answer is B. The two main types of nuclear decay are alpha and beta decay, which are differentiated based on the emitted particle. In alpha decay, an alpha particle (consisting of two protons and two neutrons) is emitted from the nucleus, while in beta decay, a beta particle (either an electron or a positron) is emitted. These decay types are distinguished by the particles they emit, not by the size of the nucleus, trigger, or stability of the nucleus. Choices A, C, and D are incorrect because fission, fusion, spontaneous, induced, isotope decay, and chain reactions are different processes in nuclear physics and do not represent the two main types of nuclear decay based on emitted particles.

Correct Answer: B

Rationale: The correct answer is B because if an object is initially at rest and no force is acting on it, it will remain at rest due to Newton's First Law of Motion. This law states that an object at rest will stay at rest unless acted upon by an external force. Choices A, C, and D all involve forces acting on the object, which would cause it to move according to Newton's laws of motion. Choice A, a constant force acting on the object, would cause it to move at a constant velocity. Choice C, a force that increases in magnitude over time, would accelerate the object. Choice D, a force that decreases in magnitude over time, would decelerate the object.