1. Molecules in a certain medication attach to receptors on nerve cells. This prevents the normal chemical signal from binding to the receptor. One immediate result of taking this medication might be a disruption in the ability of A) the body to produce reproductive cells B) cells to communicate with each other C) cells to synthesize proteins D) the body to convert inorganic material into organic nutrients 2. Acetylcholine is a chemical secreted at the ends of nerve cells. This chemical helps to send nerve signals across synapses (spaces between nerve cells). After the signal passes across a synapse, an enzyme breaks down the acetylcholine. LSD is a drug that blocks the action of this enzyme. Describe one possible effect of LSD on the action of acetylcholine.

3. A process that occurs in the human body is Base your answers to questions 4 through 6 on the represented in the diagram below. diagram below and on your knowledge of biology.

Which statement is most closely associated with the 4. A drug is developed that, due to its molecular shape, diagram? blocks the action of substance A. Which shape would A) Small molecules are obtained from large the drug molecule most likely resemble? molecules during digestion. A) B) C) D) B) Certain molecules are replicated by means of a template. 5. Which statement best describes the diagram? C) Receptor molecules play an important role in communication between cells. A) Nerve cell X is releasing receptor molecules. D) Energy from nutrients is utilized for waste B) Nerve cell Y is signaling nerve cell X. disposal. C) Nerve cell X is attaching to nerve cell Y. D) Nerve cell Y contains receptor molecules for substance A. 6. The process represented in the diagram best illustrates A) cellular communication B) muscle contraction C) extraction of energy from nutrients D) waste disposal 7. Two types of human cells are shown in the diagram 11. In a simple spinal reflex, the pathway for an impulse below. is along a sensory neuron directly to a motor neuron through A) an effector B) a receptor C) an interneuron D) the brain 12. A blind student runs his fingers along a page of braille. Another student reads a page printed in a textbook. Both students are able to obtain and Cell A causes the cells at B to contract. This activity process the information most directly as a result of would be most useful for the activities of the A) lifting a book from a bookshelf A) sensory neurons and cerebrum B) coordinating the functions of organelles B) involuntary muscles and cerebellum C) digesting food in the small intestine C) interneurons and spinal cord D) carrying out the process of protein synthesis D) smooth muscles and medulla 8. Which statement accurately compares cells in the 13. When leg muscles respond to a stimulus by moving human circulatory system to cells in the human the foot, the response depends most directly on the nervous system? functioning of A) Cells in the circulatory system carry out the A) bronchioles B) nephrons same life function for the organism as cells in C) capillaries D) neurons the nervous system. 14. Base your answer to the following question on B) Cells in the circulatory system are identical in the diagram below and on your knowledge of structure to cells in the nervous system. biology. C) Cells in the nervous system are different in structure from cells in the circulatory system, and they carry out different specialized functions. D) Cells in the nervous system act independently, but cells in the circulatory system function together. 9. In humans, one function of an interneuron is to relay impulses directly from A) receptors to the brain B) receptors to other receptors C) motor neurons to receptors D) a sensory neuron to a motor neuron 10. Which structures in a human transmit Failure of structure A to function properly would electrochemical messages? most directly disrupt A) veins B) lymphocytes A) autotrophic nutrition C) neurons D) nephrons B) chromosome replication C) cellular communication D) biological evolution 15. In the human central nervous system, the medulla 19. A man suffers a head injury in a car accident. For directly controls several days afterward, he has difficulty remembering phone numbers. This loss of memory A) voluntary activity results from damage to the man's B) memory C) involuntary activity A) cerebrum B) cerebellum D) balance C) medulla D) spinal cord 16. Which portion of the central nervous system 20. An increase in the amount of carbon dioxide in the coordinates motor activities and aids in maintaining blood stimulates the respiratory center of the brain. balance? As a result, impulses are sent from the A) cerebrum B) cerebellum A) medulla to the diaphragm, increasing the C) medulla D) spinal cord rate of breathing B) cerebrum to the chest muscles, decreasing the Base your answers to questions 17 and 18 on the rate of breathing diagram below which represents the human brain and C) medulla to the trachea, causing it to constrict on your knowledge of biology. D) cerebrum to the alveoli, causing them to actively transport oxygen 21. In humans, the center for regulating the amount of oxygen in the blood is situated in the A) cerebrum B) cerebellum C) medulla D) spinal cord 22. Impulses originating in the part of the brain called the medulla would most directly affect which body structure? A) a leg muscle B) a ligament C) an arm bone D) the heart 23. Memory and thinking are most closely associated with which part of the central nervous system? 17. Which are the correct structure and function for the A) spinal cord B) medulla part indicated by letter B? C) cerebrum D) cerebellum A) cerebrum ® balance B) cerebellum ® muscle coordination C) medulla ® problem solving D) spinal cord ® reflex actions 18. Which processes would most likely be affected if the part of the brain indicated by letter A was damaged? A) ability to contract muscles in the walls of arteries B) reflex actions and involuntary behavior patterns C) involuntary activities such as breathing and peristalsis D) reasoning and speech 24. Opiate drugs, such as heroin, imitate endorphins, 28. The peripheral nervous system consists of the which are a type of neurotransmitter that is naturally A) neurons located in the brain and spinal cord produced in the brain. How does heroin affect cellular communication in the brain? B) nerves that extend from the brain and spinal cord A) Heroin gives the brain false signals because C) interneurons of the central nervous system the neurons respond to the heroin as if it D) portions of the brain known as the medulla and were a neurotransmitter. cerebellum B) Heroin does not affect the brain because neurons ignore the drugs and do not respond to 29. The part of the human central nervous system that them. conducts impulses from the brain to the peripheral nervous system is protected by the C) Heroin slows down cellular communication because it decreases the ability of a neuron to A) vertebrae B) effectors detect all types of neurotransmitters. C) receptors D) glomeruli D) Heroin blocks the ability of the neurons to 30. Regulation of heart rate is most closely associated transmit any kind of signals and causes brain with the death. A) cerebrum 25. The diagram below represents the human brain B) cerebellum C) somatic nervous system D) autonomic nervous system 31. The contraction of the biceps and triceps muscles in the human arm is regulated by the A) autonomic nervous system B) pituitary gland C) somatic nervous system D) hypothalamus The structure labeled X is most directly involved in 32. When a child runs to his mother after hearing a clap the of thunder, the child is using A) control of breathing and heartbeat A) the central nervous system, only B) maintenance of coordination and balance B) the peripheral nervous system, only C) interpretation of sensory impulses C) both the central and the peripheral nervous D) initiation of voluntary actions systems D) neither the central nor the peripheral nervous 26. The nerves that directly control the muscles used in system writing are A) part of the autonomic nervous system B) regulated by the hypothalamus C) part of the somatic nervous system D) regulated by the medulla 27. The part of the human central nervous system that controls breathing is the A) cerebrum B) cerebellum C) medulla D) spinal cord 33. Base your answer to the following question on the 35. Which is an activity controlled primarily by the diagram below, which represents the two systems autonomic nervous system? involved in regulation, and on your knowledge of A) thinking during an exam biology. B) writing your name C) regulating heartbeat D) chewing food 36. Rapid messages are sent from the brain to muscles and glands of the human body by way of the A) spinal cord and peripheral nervous system B) sensory neurons located in sensory nerves C) red blood cells and blood plasma D) lymph vessels and lymph nodes 37. The portion of the nervous system that is most closely associated with the contraction of cardiac Which type of muscle is not controlled by the region muscle is the of the nervous system indicated by box C? A) autonomic nervous system A) cardiac muscle B) smooth muscle B) somatic nervous system C) skeletal muscle D) visceral muscle C) cerebrum D) hypothalamus 34. The diagram below represents a system in a human body. 38. The regulatory system of humans includes endocrine glands and a A) ventral nerve cord with connecting nerves B) ventral nerve cord within a nerve net C) dorsal nerve cord with connecting nerves D) dorsal nerve cord within a nerve net 39. The somatic nervous system contains nerves that run from the central nervous system to the A) muscles of the skeleton B) heart C) smooth muscles of the gastrointestinal tract D) endocrine glands 40. Which organism possesses a dorsal nerve cord? A) hydra B) human C) paramecium D) earthworm This body system is most directly involved in A) production of blood cells B) stimulation of rapid growth responses C) elimination of body wastes D) initiation of muscle contraction 41. If a motor neuron involved in a reflex arc is 44. In the reflex arc represented by the diagram below, damaged, which event in that arc is least likely to which type of substance is normally secreted in the occur? area indicated by letter X? A) contraction of a muscle B) stimulation of an interneuron C) reception of a stronger stimulus by the sense organ D) secretion of a neurotransmitter by the sensory neuron 42. The diagram below represents a reflex arc.

A) an antibody B) a pigment C) a neurotransmitter D) an antigen 45. Which is the first structure stimulated in a reflex arc? A) interneuron B) motor neuron C) effector D) receptor The function of the neuron labeled X is to 46. Which is a correct route of an impulse in a reflex A) transmit impulses from a sensory neuron to arc? a motor neuron A) receptor ® sensory neuron ®interneuron B) direct impulses from the receptor to the spinal ® motor neuron ® effector cord B) effector ® receptor® motor neuron ®sensory C) initiate responses by stimulating the receptor neuron ® interneuron D) transmit impulses from the effector to the brain C) sensory neuron ® effector ® motor neuron ® 43. A reflex arc is illustrated in the diagram below. receptor ® interneuron D) motor neuron ® sensory neuron ®interneuron ® effector

Structure X represents A) an effector B) a motor neuron C) an interneuron D) a receptor