Comparison between hormonal mechanisms are as follows :

Adrenaline hormone is secreted from adrenal gland into the blood and carried to different parts of the body. At the time of emergency, danger or stress, it is released in large quantities. As a result, it causes fast beating of heart, resulting in more supply of oxygen to muscles.
The blood supply to the digestive system and skin is reduced due to contraction of muscles around small arteries in these organs. The breathing rate also increases because of the contraction of diaphragm and rib muscles. All these responses together help the animal to deal with the emergency situation.

Auxins promote cell elongation and are present at the shoot tip. When tendril comes in contact with a support, auxin stimulates faster growth of the cells on the opposite sides. Thus, the tendril coils around the support.

Auxin is a plant hormone, which promotes growth in plants.

Brain has limited role to play in reflex action. It is an extremely quick action, which does not involve any thinking by the brain. In this type of action, the stimulus is received by the spinal cord that sends a response,e.g. coughing, The action is registered in cercbral brain just for memory.

The smell reaches the neurons of olfactory receptor of nose. It causes the generation of nerve impulses that reach the olfactory lobes of the forebrain to produce the sensation of smell.

Cerebellum is the part of hindbrain that maintains posture and equilibrium of the body.

The differences between a reflex action and walking are as follows:

Voluntary actions are under the control of our will, it needs thinking. e.g. talking, walking. Involuntary actions are not under the control of our will, they are automatic. eg. salivation, heart beat.

Information passes through neuron in the form of electro-chemical signals. These signals are called impulse.
When an impulse reaches the end of the axon it sets off the release of some chemicals. These chemicals cross the gap or the synapse and start a similar electrical impulse in a dendrite of the next neuron. A similar synapse allows the delivery of impulses from the neurons to other cells, like muscle cells or glands.

(i) Regions included in central nervous system are the brain and the spinal cord. The brain and the spinal cord. The brain is further divided into three parts - forebrain, midbrain, and hindbrain.
(ii) Three of the functions of the brain are:
Forebrain controls intelligence, learning, memory, thinking, speech, etc.
Midbrain is associated with the sense of sight and hearing.
Hindbrain controls all involuntary actions such as breathing, peristalsis, etc.

Tropic movements are directional movements which are either towards the stimuli or away from it.
(i) Phototropism: Movement is in response to light: stem positive, root negative.
(ii) Geotropism: Movement is in response to gravity: stem negative, root positive.
(iii) Hydrotropism: Movement in response to water: stem negative, root positive.
(iv) Chemotropism: Growth of pollen tubes towards ovules.
For example, the shoot usually grows in the direction of sunlight. This is called positive phototropic movement.

The flow of signals through neurons takes place in the form of specialized chemicals; called neurotransmitters. The neurotransmitters. The neurotransmitters can only enter a neuron through dedicated receptor channels. Such receptor channels a5re only present at the dendritic end but not at the axonal end. Hence, the flow of signals in a synapse happens from axonal end of one neuron to dendritic end of another neuron but not in the reverse direction.

The endocrine and neural system both works together for the normal functioning of our body. The synthesis and release of certain hormones is regulated by the neural system. Also, the release of certain hormones influences the activity of nerves.
For example, hypothalamus receives neural signals from brain and releases hormones.
In case of deficiency of iodine, body produces less thyroxine hormone. Hypothalamus releases hormones to stimulate pituitary gland which further stimulates thyroid gland to secrete thyoxine.

Reflex action is a special case of involuntary movement involuntary organs. When a voluntary organ is in the vicinity of a sudden danger, it is immediately pulled away from the danger to save itself. For example; when your hand touches a very hot electric iron, you move away your hand in a jerk. All of this happens in flash and your hand is saved from the imminent injury. This is an example of reflex action.
Reflex Arc: The path through which nerves signals; involved in a reflex action; travel is called the reflex arc. The following flow chart shows the flow of signal in a reflex arc. Receptor \(\rightarrow\) Sensory Neuron\(\rightarrow\) Relayneuron \(\rightarrow\) Motor neuron \(\rightarrow\) Effector (muscle) The receptor is the organ which comes in the danger zone. The sensory neurons pick signals from the receptor and send them to the relay neuron. The relay neuron is present in the spinal cord. The spinal cord sends signals to the effector via the motor neuron. The effector comes in action moves the receptor away from the danger.

Various plant hormones and their effects are as follows:
(i) Auxin : Promotes cell elongation and thus promotes growth of a plant part.
(ii) Gibberellins : Promotes growth.
(iii) Cytokinin :  Promotes cell division and thus promotes growth.
(iv) Abscissic acid : Inhibits growth and is responsible for shedding or older parts.

(a) General metabolism.
(b) Controls blood sugar level.
(c) Prepare the body for 'fight or flight' response.
(d) Promotes growth and development.
(e) Triggers sperm production and is responsible for the development of secondary sexual characters in males.

The central nervous is composed of the brain and the spinal cord. The peripheral nervous system is composed of cranial nerves, spinal nerves and the autonomous nervous system. Brain gets the maximum protection, as it is found inside the skull. Spinal cord gets protection by the vertebral column. Additionally, the brain and the spinal cord are surrounded by a system of three layers called meninges. The cerebrospinal fluid is filled between these membranes which provide a cushion against mechanical shocks.

(c) If assertion is true and reason is false.

(b) If both assertion and reason are true but reason is not a correct explanation of assertion.

(a) If both assertion and reason are true and the reason is correct explanation of assertion.

(a) If both assertion and reason are true and the reason is correct explanation of assertion.

(i) The woman who has TSH 6.03 mU/L should take iodine rich diet and should use iodised salt.
(ii) Women are at a greater risk for developing abnormal TSH levels during menstruation, while giving birth and after going through menopause.
(iii) Low TSH level causes goitre disease.
(iv) Iodine is required for synthesis of thyroxine by thyroid gland.

(i) Auxin causes the root and shoot to develop in the way shown in the above figure.
(ii) Auxin is synthesised at the shoot tip. When plant is exposed to unidirectional light auxin diffuses to shady side and causes all elongation. In this way, auxin controls the growth response of the shoot.
(iii) Gravity the response is called geotropism.
Or
(iii) Light the respones is called phototropism.