Tag: life processes: control and coordination

Questions Related to life processes: control and coordination

Joint between axon of a neuron and dendrite of next is called

  1. Synapse

  2. Synapsis

  3. Junction

  4. Bridge


Correct Option: A

Synapse is......

  1. Crossing over between nonhomologous chromosomes

  2. Pairing of homologous chromosomes

  3. Junction between axon and dendrite of two different neurons

  4. Zigzag junction in cardiac muscle fibres


Correct Option: C

Association between telodendria and dendrites is known as

  1. Synapse

  2. Aynapse

  3. Trinapse

  4. Dynapse


Correct Option: A

Which of the following options correctly described the sequence of structures present between a receptor and an effector when D refers dendrite, A refers axon, S refers synapse and CB refers to cell body?

  1. D - CB - A - S - D - CB - A

  2. A -D - CB - S - A - D - CB

  3. D - CB - A - S - A - CB - D

  4. D - A - S - CB - D - A - CB


Correct Option: A

The chemicals which are released at the synaptic junction are known as

  1. Cerebrospinal fluid

  2. Hormones

  3. Neurotransmitters

  4. Lymph


Correct Option: C
Explanation:

Neurotransmitters are the brain chemicals that communicate information throughout our brain and body. They relay signals between nerve cells called as neurons. They are the chemicals which allow the transmission of signals from one neuron to the next across synapses. They are also found at the axon endings of motor neurons, where they stimulate the muscle fibres. So, the correct answer is option C.

Select the option responsible for restoring resting membrane potential of a neuron

  1. Voltage gated ${ Na }^{ + }$ channels

  2. Voltage gated ${ K }^{ + }$ channels

  3. Leaky channels for ${ K }^{ + }$

  4. ${ Na }^{ + }/{ K }^{ + }$ pump


Correct Option: D
Explanation:

The Sodium-Potassium pump is the process of moving sodium and potassium ions across the cell membrane is an active transport process involving the hydrolysis of ATP to provide the necessary energy. It involves an enzyme referred to as Na+/K+.

So, the correct option is 'Na+/K+ pump'.

Nerve impulse generation is a

  1. Physical process

  2. Chemical process

  3. Effected process

  4. Electro-chemical process


Correct Option: D
Explanation:
A nerve impulse is a way nerve cells (neurons) communicate with one another. Nerve impulses are mostly electrical signals along the dendrites to produce a nerve impulse or action potential. The action potential is the result of ions moving in and out of the cell.

In thinking and response to external stimulus the brain take time about

  1. Less than 1/10th sec

  2. 1/10th sec

  3. More than 1/10th sec

  4. About 1 sec


Correct Option: B
Explanation:

The human nervous system is highly developed. The external stimulus leads to generation of impulse. This impulse is conducted through sensory neurons and the response is given by the effector organ on receiving the answer given by the brain. The time taken by the brain and the nervous system to give the response is considered as in fraction of a second. So, the correct answer is option B.

You are watching a horror movie and you notice your heart is beating fast and mouth is dry; it is because

  1. Fight and flight response

  2. Autonomic nervous system

  3. Sympathetic nervous system

  4. Both A and C

  5. Release of acetylcholine


Correct Option: D
Explanation:
You are watching a horror movie and you notice your heart is beating fast and mouth is dry; it is because of fight and flight response and sympathetic nervous system.
Fight and flight response is acute stress response.
The fight-or-flight response occurs in response to a perceived harmful event, attack, or threat to survival. The sympathetic nervous system originates in the spinal cord and its main function is to activate the physiological changes that occur during the fight-or-flight response. This component of the autonomic nervous system utilizes and activates the release of norepinephrine in the reaction.
The physiological changes that occur during the fight or flight response are activated in order to give the body increased strength and speed in anticipation of fighting or running. Some of the specific physiological changes and their functions include:
Increased blood flow to the muscles activated by diverting blood flow from other parts of the body.
Increased blood pressure, heart rate, blood sugars, and fats in order to supply the body with extra energy.
The blood clotting function of the body speeds up in order to prevent excessive blood loss in the event of an injury sustained during the response.
Increased muscle tension in order to provide the body with extra speed and strength.

Sight of delicious food usually makes mouth watery, it is a 

  1. Hormonal response

  2. Neural response

  3. Optic response

  4. Olfactory response


Correct Option: B
Explanation:

The response to food begins even before food enters the mouth. The first phase of ingestion, called as the cephalic phase, is controlled by the neural response to the stimulus provided by food. All aspects, such as sight, sense, and smell, trigger the neural responses resulting in salivation and secretion of gastric juices. The gastric and salivary secretion in the cephalic phase can also take place at the thought of food. The central nervous system prepares the stomach to receive food.