Control and Co-ordination

Match the terms of Column (A) with these of Column (B) :

• A-(iii), B-(iv), C-(i), D-(ii)

• A-(ii), B-(iii), C-(iv), D-(i)

• A-(i), B-(ii), C-(iii), D-(iv)

• A-(iv), B-(ii), C-(iii), D-(i)

The following stages occur in a reflex action :

1. 1. Receptor detects a stimulus.

2. 2. Sensory neuron sends impulses to relay neuron.

3. 3. Effector produces a response.

4. 4. Motor neuron sends impulses to effector.

The correct order of the stages is :

• 2, 3, 4, 1

• 2, 1, 4, 3

• 1, 2, 4, 3

• 3, 4, 1, 2

The below picture shows two neurons. A nerve impulse moves from Neuron A to Neuron B because of :

• the release of various carbohydrates into the synapse.

• the release of chemicals called neurotransmitters.

• the dendrites that are connected.

• Neuron A hitting against Neuron B.

Which of the following diagrams shows hydrotropism ?

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Identify the correct names of hormones from the following hints.

I. “X” hormone induces fruit ripening.

II. “Y” hormone promotes root initiation and also play a role in callus differentiation

III. “Z” hormone increases the tolerance of plant to various stresses and play an important role in

seed dormancy.

• Y = ABA; X = Auxin; Z = Gibberellin

• Z = Gibberellin; X = Auxin; Y = Ethylene

• Y = Auxin; X = Ethylene; Z = Gibberellin

• X = Ethylene; Y = Auxin; Z = ABA

What is the correct direction of the flow of electrical impulses?

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Electrical impulse travels in a neuron from :

• Dendrite → axon → axonal end → cell body

• Cell body → dendrite → axon → axonal end

• Dendrite → cell body → axon → axonal end

• Axonal end → axon → cell body → dendrite

Which is the correct sequence of the components of a reflex arc?

• Receptors→ Muscles→ Sensory neuron→ Motor neuron→ Spinal cord

• Receptors→ Motor neuron → Spinal cord → Sensory neuron → Muscle

• Receptors → Spinal cord → Sensory neuron → Motor neuron → Muscle

• Receptors → Sensory neuron → Spinal cord → Motor neuron → Muscle

Identify P, Q and R in the given figure :

• P-Cerebellum, Q-Cerebrum, R-Medulla oblongata

• P-Cerebrum, Q-Medulla oblongata, R-Cerebellum

• P-Cerebrum, Q-Cerebellum, R-Medulla oblongata

• P-Medulla oblongata, Q-Cerebrum, R-Cerebellum

Assertion : Phtotropism in plants is caused by auxin.

Reason : Plants showing bending has more elongated cells on the illuminated side.

• Assertion and Reason are true and Reason is the correct explanation of Assertion

• Assertion and Reason are true and Reason is not the correct explanation of Assertion

• Assertion is true but Reason is false

• Assertion is false but Reason is true