Tag: biology

Questions Related to biology

Recently, a new device is innovated which allows brain to bypass spinal cord and can directly send signal to limbs and thus can allow movement of paralysed limbs. What kind of signals the device must be generating which controls these muscles?

biology control and co-ordination in plants and animals voluntary and involuntary movements impulse and its transmission coordination in human beings- nervous control

  1. Thermal signals

  2. Electric signals

  3. Optical signals

  4. Chemical signals

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Correct Option: B
Explanation:

A new device referred as neurobridge, have been discovered that can by pass the signals from brain to the limbs with the help of electric signals. For the very first time, such device have been developed which helps to reconnect the brain directly to the muscles allowing voluntary and funcutional control of a paralyzed limb. 

A nerve impulse leaves a neuron through the

biology control and co-ordination in plants and animals voluntary and involuntary movements impulse and its transmission coordination in human beings- nervous control

  1. Dendrites

  2. Cyton

  3. Axon

  4. Nucleus

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Correct Option: C
Explanation:

For nerve impulses to be generated and carried, nerve cells should be in contact with each other. The nerve impulse is transmitted in the following sequence:  Axon end- synapse- dendrites- dendron- cyton- axon body- axon end. A nerve impulse travels in a form of electrical charge from axon end to the synapse. Here, the electrical impulse is converted to the chemical impulse in the synaptic cleft. Further this nerve impulse flows from synaptic cleft to dendritic tips, converting the chemical impulse to electrical impulse. Thus, the flow of impulse always flows from one axonal end of a neuron to another dendronal head of a neuron. So, the correct answer is option C.

Which of the following statement about a transmission of a nerve impulse is correct?

biology control and co-ordination in plants and animals voluntary and involuntary movements impulse and its transmission coordination in human beings- nervous control

  1. Nerve impulse travels from dendritic end towards axonal end.

  2. A neuron transmits electrical impulses not only to another neuron but also to muscle and gland cells.

  3. The chemicals released from the axonal end of one neuron cross the synapse and generate a similar electrical impulse in a dendrite of another neuron.

  4. All of the above.

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Correct Option: D
Explanation:

For nerve impulses to be generated and carried, nerve cells should be in contact with each other. The nerve impulse is transmitted in the following sequence: 
Axon end- synapse- dendrites- dendron- cyton- axon body- axon end. A nerve impulse travels in a form of electrical charge from axon end to the synapse. Here, the electrical impulse is converted to the chemical impulse in the synaptic cleft. Further this nerve impulse flows from synaptic cleft to dendritic tips, converting the chemical impulse to electrical impulse. Thus, the flow of impulse always flows from one axonal end of a neuron to another dendronal head of a neuron. So, the correct answer is option D.

Muscle A and muscle B are the same size, but muscle A is capable of much finer control than muscle B. Which B. Which one of the following is likely to be true of muscle A?

biology control and co-ordination in plants and animals voluntary and involuntary movements impulse and its transmission coordination in human beings- nervous control

  1. It contains fewer motor units than muscle B.

  2. It has larger sarcomeres than muscle B.

  3. IT is controlled by more neurons than muscle B.

  4. It is controlled by ewer neurons than muscle B.

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Correct Option: A

Lactic acid is generally formed in very fast acting muscle but exceptional muscle is

biology control and co-ordination in plants and animals voluntary and involuntary movements impulse and its transmission coordination in human beings- nervous control

  1. Muscles of Iris and pupil

  2. No exception is found

  3. Muscles of heart

  4. Muscles of jaw

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Correct Option: A

Transmission of a nerve impulse across _____very similar to impulse conduction along axon.

biology control and co-ordination in plants and animals voluntary and involuntary movements impulse and its transmission coordination in human beings- nervous control

  1. Ranvier's node

  2. Chemical synapse

  3. Electrical synapse

  4. Myelin sheath

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Correct Option: B

Muscles cell are branched. 

biology control and co-ordination in plants and animals voluntary and involuntary movements impulse and its transmission coordination in human beings- nervous control

  1. True

  2. False

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Correct Option: B

Conduction of nerve impulse is 

biology control and co-ordination in plants and animals voluntary and involuntary movements impulse and its transmission coordination in human beings- nervous control

  1. Faster in non-myelinated fibres

  2. Faster in myelinated fibres

  3. No difference in the rate of conduction in myelinated and non -myelinated fibres.

  4. None of the above

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Correct Option: B
Explanation:

Conduction of nerve impulse is faster in myelinated fibres as myelin is an insulating layer or sheath, that forms around nerves, including those in the brain and spinal cord which protect and insulates the axons thus enhance the transmission of electrical impulses.

So, the correct answer is option B.

Axon is characterised by

biology control and co-ordination in plants and animals voluntary and involuntary movements impulse and its transmission coordination in human beings- nervous control

  1. Transformation of energy

  2. Receiving the impulse

  3. Providing energy for impulse

  4. Conduction of impulse

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Correct Option: D
Explanation:

Axon is the long slender part of the neuron. It conducts nerve impulse from the dendron towards the synapse. So, option D is the correct answer.

The gap between two neuron is _____

biology control and co-ordination in plants and animals voluntary and involuntary movements impulse and its transmission coordination in human beings- nervous control

  1. 2-20 nm

  2. 25-30nm

  3. 150-200nm

  4. 50-60nm

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Correct Option: A
Explanation:

The gap between 2 neurons is called synapse. This signal between two neuron is passes when this synapse is filled with neurotransmitter. The size of the synapse ranges from 2-20 nm.