the involuntary reflex arc that withdraws your hand from a hot object involves the

ATI TEAS 7

TEAS 7 science practice

1. What is involved in the involuntary reflex arc that withdraws your hand from a hot object?

A. Central nervous system only
B. Peripheral nervous system only
C. Both CNS and PNS
D. Sensory neurons only

Correct answer: C

Rationale: The involuntary reflex arc that withdraws your hand from a hot object involves both the central nervous system (CNS) and the peripheral nervous system (PNS). When your hand touches a hot object, sensory neurons in the PNS detect the heat and send signals to the spinal cord in the CNS. The spinal cord processes this information and sends a signal back through motor neurons in the PNS to move your hand away from the hot object. This coordinated response requires the collaboration of both the CNS and PNS to protect the body from harm. Choice A is incorrect because the reflex arc involves more than just the central nervous system. Choice B is incorrect because the reflex arc involves more than just the peripheral nervous system. Choice D is incorrect because the reflex arc also involves motor neurons, not just sensory neurons.

2. What is the basic structural and functional unit of the nervous system?

A. Axon
B. Neuron
C. Dendrite
D. Synapse

Correct answer: B

Rationale: The correct answer is B: Neuron. Neurons are indeed the basic structural and functional units of the nervous system. Neurons are specialized cells that transmit signals throughout the nervous system, enabling communication and coordination of various functions within the body. While axons, dendrites, and synapses are all essential components of neurons and neural function, the neuron as a whole is considered the fundamental building block responsible for signal transmission. Choice A, Axon, is incorrect because an axon is a part of a neuron responsible for transmitting electrical signals away from the cell body. Choice C, Dendrite, is incorrect because dendrites are extensions of a neuron that receive signals from other neurons. Choice D, Synapse, is incorrect because a synapse is the junction between two neurons where signals are transmitted.

3. What is the significance of cell division?

A. Growth and repair of tissues
B. Sexual reproduction
C. Genetic diversity
D. All of the above

Correct answer: D

Rationale: Cell division is a fundamental process that serves multiple critical functions in living organisms. It is essential for the growth and repair of tissues by enabling the formation of new cells to replace old or damaged ones. Moreover, cell division plays a pivotal role in sexual reproduction as it is involved in the production of gametes necessary for fertilization. Additionally, cell division contributes to genetic diversity through processes like meiosis, which leads to the formation of genetically distinct gametes. Therefore, the correct answer is D, 'All of the above,' as cell division is significant for growth, repair, sexual reproduction, and genetic diversity. Choices A, B, and C are incorrect because they each represent only one aspect of the significance of cell division, whereas the correct answer encompasses all the essential roles that cell division plays in living organisms.

4. What is the normal (complete) flow of blood through the heart?

A. Right atrium → lungs → left atrium → body
B. Left atrium → left ventricle → body → right atrium
C. Right atrium → right ventricle → lungs → left atrium → left ventricle → aorta → body
D. Right ventricle → left ventricle → body

Correct answer: C

Rationale: The correct flow of blood through the heart starts with the right atrium receiving deoxygenated blood from the body, followed by the right ventricle pumping blood to the lungs for oxygenation. Oxygenated blood then returns to the heart through the left atrium, then passes to the left ventricle which pumps it out to the body through the aorta. This flow ensures that blood is properly oxygenated before circulating through the body. Choice A is incorrect as the blood does not go directly from the left atrium to the body, skipping the left ventricle. Choice B is incorrect as it does not follow the correct flow sequence in the heart. Choice D is incorrect as it does not include the full pathway of blood through the heart.

5. What is the net force acting on a car traveling at a constant speed on a straight road?

A. A force equal to its weight pushing upwards
B. A force equal to its weight pushing downwards
C. A force equal to its engine power pushing forward
D. No net force

Correct answer: D

Rationale: When a car is traveling at a constant speed on a straight road, it indicates that the forces acting on the car are balanced. In this scenario, there is no acceleration or deceleration, meaning the net force on the car is zero. If there was a net force present, it would cause the car to either accelerate or decelerate. Choices A, B, and C are incorrect because in a situation where a car is moving at a constant speed, the forces are balanced, and there is no unbalanced force acting in any specific direction.