IB Diploma · Biology C3.1

IB Biology C3.1: Int. of Body Sys. — Practice Questions & Answers

IB Biology C3.1 Integration of body systems study notes: nervous and endocrine coordination, the brain, feedback control and homeostasis.

Here are 10 practice questions with full answers and explanations.

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Practice questions with answers

1 Multiple choice

What is the primary function of system integration in living organisms?

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WhySystem integration coordinates the organs and organ systems so the organism maintains homeostasis and responds effectively.
2 Multiple choice

What does the integration of cells, tissues, organs, and body systems lead to in multicellular organisms?

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WhyIntegrating cells, tissues, organs and systems gives rise to emergent properties not present in the parts alone.
3 Multiple choice

What is the main role of the brain in system integration?

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WhyThe brain integrates multiple inputs and underlies learning and memory in system integration.
4 Multiple choice

What is the role of the spinal cord in integration?

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WhyThe spinal cord acts as an integrating centre for unconscious processes such as reflexes.
5 Multiple choice

How does sensory input reach the spinal cord and cerebral hemispheres?

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WhySensory neurons carry input from receptors to the spinal cord and cerebral hemispheres.
6 Multiple choice

How does output from the cerebral hemispheres reach muscles?

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WhyMotor neurons carry output from the cerebral hemispheres to muscles to produce movement.
7 Multiple choice

What are nerves?

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WhyA nerve is a bundle of axons from many neurons, enclosed in connective tissue, that transmits impulses to and from the CNS.
8 Multiple choice

What is a pain reflex arc an example of?

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WhyA pain reflex arc is an involuntary response in which skeletal muscle acts as the effector.
9 Multiple choice

What is the role of the cerebellum?

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WhyThe cerebellum coordinates skeletal muscle contraction and maintains balance.
10 Multiple choice

What modulates sleep patterns?

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WhyMelatonin, secreted by the pineal gland, modulates sleep patterns and circadian rhythm.

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Key terms in Int. of Body Sys.

Integration: The coordinated working together of the body’s systems so that the organism functions as a single whole.
Nervous system: The system that coordinates the body using rapid electrical impulses carried by neurons.
Endocrine system: The system that coordinates the body using hormones released into the blood, giving slower, longer-lasting effects.
Central nervous system: The brain and spinal cord, where sensory information is processed and responses are coordinated.
Reflex arc: The neural pathway of an automatic response: receptor, sensory neuron, relay neuron, motor neuron and effector.
Homeostasis: The maintenance of a stable internal environment within narrow limits despite external change.
Negative feedback: A control mechanism in which a change triggers a response that reverses the change and restores the set point.
Hypothalamus: A brain region that controls homeostasis and links the nervous and endocrine systems.

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Practise other IB Biology topics

A1.1 Water A1.2 Nucleic Acids A2.1 Orig. of cells A2.2 Cell Structure A2.3 Viruses A3.1 Div. of Org. A3.2 Clas. & Clad. A4.1 Evo. & Spec. A4.2 Cons. of Biodiv. B1.1 Carb. & Lipids B1.2 Proteins B2.1 Mem. & Mem. Trans. B2.2 Org. & Compart. B2.3 Cell Spec. B3.1 Gas Exchange B3.2 Transport B3.3 Muscle & Motility B4.1 Adapt. to Envir. B4.2 Eco. niches C1.1 Enzy. & Meta. C1.2 Cell Resp. C1.3 Photosynthesis C2.1 Chem. Signal. C2.2 Neu. Signal. C3.2 Def. against Dis. C4.1 Pop. & Commu. C4.2 Tran. of En. & Mat. D1.1 DNA Replication D1.2 Protein Syn. D1.3 Mut. & Gene Edit. D2.1 Cell & Nuc. Div. D2.2 Gene Exp. D2.3 Water potential D3.1 Reproduction D3.2 Inheritance D3.3 Homeostasis D4.1 Nat. Select. D4.2 Stab. & Change D4.3 Climate Change DIAG Diagnostic Questions