Consider the following statements regarding coordination in the human body:
I. Coordination is the process through which two or more organs interact and complement the functions of one another. II. During physical exercise, the increase in muscular activity is complemented by an increased rate of respiration, heart beat, and blood flow. III. The neural system provides chemical integration through hormones for quick, point-to-point coordination. IV. The endocrine system and neural system jointly coordinate and integrate all activities of the organs so that they function in a synchronized fashion.
Statements I, II and IV are correct. Statement III is incorrect because the neural system provides rapid point-to-point coordination through nerve impulses, whereas the endocrine system provides chemical integration through hormones.
Question 2 of 100
📘 CLASS XI
Analyze the statements below regarding the comparative study of neural systems across animal groups:
I. In Hydra, the neural organization is extremely simple and is composed of a network of neurons. II. Insects possess a better organized neural system containing a brain, ganglia, and neural tissues. III. Invertebrates have a more developed neural system than vertebrates. IV. The neural system of all animals is composed of highly specialized cells called neurons.
Statements I, II and IV are correct. Statement III is incorrect because vertebrates possess a more highly developed nervous system than invertebrates.
Question 3 of 100
📘 CLASS XI
Regarding the peripheral nervous system (PNS), evaluate the following statements:
I. Afferent nerve fibres transmit regulatory impulses from the Central Neural System (CNS) to peripheral tissues or organs. II. Efferent nerve fibres transmit sensory impulses from tissues or organs to the Central Neural System (CNS). III. The somatic neural system relays impulses from the CNS to skeletal muscles. IV. The autonomic neural system transmits impulses from the CNS to involuntary organs and smooth muscles.
Statements III and IV are correct. Statements I and II are incorrect because afferent fibres carry sensory impulses to the CNS, whereas efferent fibres carry motor impulses from the CNS to peripheral organs.
Question 4 of 100
📘 CLASS XI
Study these statements regarding the autonomic and visceral divisions of the nervous system:
I. The autonomic neural system is divided into sympathetic and parasympathetic neural systems. II. The visceral nervous system is a part of the central nervous system comprising brain tracts. III. The visceral nervous system comprises the whole complex of nerves, fibres, ganglia, and plexuses. IV. Impulses under the visceral nervous system travel exclusively from the viscera to the CNS, but never from the CNS to the viscera.
Statements I and III are correct. Statement II is incorrect because the visceral nervous system belongs to the peripheral nervous system. Statement IV is incorrect because visceral impulses travel both from the CNS to the viscera and from the viscera to the CNS.
Question 5 of 100
📘 CLASS XI
Evaluate the following anatomical and functional characteristics of a neuron:
I. Nissl's granules are granular bodies found in the cell body (soma) as well as the repeatedly branched dendrites of a neuron. II. Dendrites are short fibres that branch repeatedly and transmit nerve impulses away from the cell body. III. Axons are long fibres whose distal ends terminate as synaptic knobs, which contain synaptic vesicles filled with neurotransmitters. IV. Axons transmit nerve impulses away from the cell body to a synapse or a neuro-muscular junction.
Statements I, III and IV are correct. Statement II is incorrect because dendrites conduct nerve impulses towards the cell body, not away from it.
Question 6 of 100
📘 CLASS XI
Consider the following statements regarding types of neurons based on structural classification:
I. Multipolar neurons possess one axon and two or more dendrites and are found in the cerebral cortex. II. Bipolar neurons contain one axon and one dendrite and are typically found in the retina of the eye. III. Unipolar neurons possess a cell body with one axon only and are usually found in the embryonic stage. IV. Myelinated nerve fibres are enveloped with Schwann cells that form a myelin sheath around the axon.
All four statements are correct. Multipolar neurons occur in the cerebral cortex, bipolar neurons are found in the retina, unipolar neurons are typical of the embryonic stage, and myelinated fibres are wrapped by Schwann cells forming the myelin sheath.
Question 7 of 100
📘 CLASS XI
Analyze the following statements regarding the structural types of axons:
I. Unmyelinated nerve fibres are enclosed by Schwann cells that do not form a myelin sheath around the axon. II. Myelinated nerve fibres are found in spinal and cranial nerves. III. Nodes of Ranvier are the gaps between two adjacent myelin sheaths along the axon. IV. Unmyelinated nerve fibres are commonly found in the autonomous and somatic neural systems.
All statements are correct. Unmyelinated fibres are enclosed by Schwann cells without forming a myelin sheath. Nodes of Ranvier are gaps between adjacent myelin sheaths. Myelinated fibres occur in cranial and spinal nerves, whereas unmyelinated fibres are commonly found in autonomic and somatic neural systems.
Question 8 of 100
📘 CLASS XI
Evaluate the following statements regarding a resting neural membrane (non-conducting neuron):
I. The axonal membrane is comparatively more permeable to potassium ions (K+) and nearly impermeable to sodium ions (Na+). II. The axonal membrane is completely permeable to negatively charged proteins present in the axoplasm. III. The axoplasm inside the axon contains high concentration of K+ and negatively charged proteins, and low concentration of Na+. IV. The fluid outside the axon contains high concentration of Na+ and low concentration of K+, forming a concentration gradient.
Statements I, III and IV are correct. Statement II is incorrect because the axonal membrane is impermeable to negatively charged proteins present in the axoplasm, contributing to the negative charge inside the resting neuron.
Question 9 of 100
📘 CLASS XI
Regarding the active transport mechanism across a resting membrane, analyze these statements:
I. The active transport of ions is driven by the sodium-potassium pump, which transports 3 Na+ outwards for 2 K+ into the cell. II. As a result of this pump, the outer surface of the resting axonal membrane becomes negatively charged and the inner surface becomes positively charged. III. The resting membrane potential is the electrical potential difference across the resting plasma membrane. IV. The pump moves ions down their concentration gradient without consuming ATP.
Statements I and III are correct. Statement II is incorrect because the sodium-potassium pump makes the outer surface relatively positive and the inner surface relatively negative. Statement IV is incorrect because the pump transports ions against their concentration gradients using ATP.
Question 10 of 100
📘 CLASS XI
What happens when a stimulus is applied to a site (e.g., site A) on a polarized membrane? Read the statements below:
I. The membrane at site A becomes freely permeable to Na+ ions, leading to a rapid influx of Na+. II. Polarity at site A is reversed; the outer surface becomes negatively charged and the inner side becomes positively charged. III. The depolarization process results in an electrical potential difference across the plasma membrane at site A called the action potential. IV. The action potential generated is in fact termed a nerve impulse.
All four statements are correct. Influx of Na+ reverses membrane polarity (depolarization), generating an action potential, which is also known as a nerve impulse.
