What is the difference between the manner
[question] Question. What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs ? [/question] [solution] solution: Movement takes place in sensitive plant due to turgor changes (changes in amount of water) which is effected by phytohormones. But movement in our leg is a voluntary action under the control of our will. Such movement are controlled by hind brain. [/solution]...
Compare and contrast nervous and hormonal mechanisms
[question] Question. Compare and contrast nervous and hormonal mechanisms for control and coordination in animals. [/question] [solution] solution: [/solution]...
How are involuntary actions and reflex actions
[question] Question. How are involuntary actions and reflex actions different from each other ? [/question] [solution] solution: Reflex actions are sudden, unconscious automatic response to some change in environment. It is controlled by spinal cord. On the other hand, involuntary actions also occur without the will of animals but these actions are controlled by either mid brain or hind brain. [/solution]...
What is the need for a system of control
[question] Question. What is the need for a system of control and coordination in an organisms ? [/question] [solution] solution: Multicellular organisms have diverse structure and functions. There are different system which perform specific function but the functioning of one system is not independent from the other. There is integration of all functional acitivities of the organism. For example, digestive enzymes are secreted into the food canal only when there is a food. The integration is po...
Which signals will get disrupted in
[question] Question. Which signals will get disrupted in case of a spinal cord injury ? [/question] [solution] solution: Spinal cord is an important component of Central Nervous system. It serves as a two way conduction path between peripheral nervous system and brain. The controlling centres in different areas of spinal cord function as reflex centres which control all the spinal reflexes. An injury in the spinal cord will disrupt the reflexes. The part of the body affected will depend upon the...
How does phototropism occur in plants ?
[question] Question. How does phototropism occur in plants ? [/question] [solution] solution: The response of a plant towards light is called as phototropism. If the plant part moves towards light, it is called positive phototropism. however, if the plant part moves away from light, then it is called negative phototropism. The stem (or shoot) of a growing plant bends towards light, so the stem (or shoot) of plant shows positive phototropism. On the other hand, the roots of a plant move away from...
Draw the structure of a neuron and explain its function.
[question] Question. Draw the structure of a neuron and explain its function. [/question] [solution] solution: Function of a neuron : (i) It helps in conducting impulses which enables the organism to show responses towards the stimuli. (ii) It helps in regulating control and coordination in animals. [/solution]...
What is the function of receptors in our body ?
[question] Question. What is the function of receptors in our body ? Think of situations where receptors do not work porperly. What problems are likely to arise ? [/question] [solution] solution: All information from environment is detected by receptors. Receptors pass information in the form of electrical impulses to brain by nerve cells and brain send information to effector organs for response. When receptors do not work properly, information from environment (stimuli) cannot be detected and ...
The brain is responsible for
[question] Question. The brain is responsible for (A) thinking. (B) regulating the heart beat. (C) balancing the body. (D) all of the above. [/question] [solution] solution: (D) all of the above. [/solution]...
The gap between two neurons is called a
[question] Question. The gap between two neurons is called a (A) dendrite. (B) synapse. (C) axon. (D) impulse. [/question] [solution] solution: (B) synapse. [/solution]...
Which of the following is a plant hormone?
[question] Question. Which of the following is a plant hormone? (A) Insulin (B) Thyroxin (C) Oestrogen (D) Cytokinin. [/question] [solution] solution: (D) Cytokinin [/solution]...
Why are some patients of diabetes treated
[question] Question. Why are some patients of diabetes treated by giving injections of insulin? [/question] [solution] solution: This is a hormone which is produced by the pancreas and helps in regulating blood sugar levels. If it is not secreted in proper amounts, the sugar level in the blood rises causing many harmful effects. [/solution]...
How does our body respond when adrenaline
[question] Question. How does our body respond when adrenaline is secreted into the blood? [/question] [solution] solution: Adrenal glands release adrenaline into blood. (i) The heart begins to beat faster resulting in supply of more oxygen to the muscles. (ii) The blood to the digestive system and skin is reduced due to the contraction of smooth muscles around small arteries in these organs.This diverts the blood to our skeletal muscles. (iii) The breathing rate increases because of the contrac...
Why is the use of iodised salt advisable?
[question] Question. Why is the use of iodised salt advisable? [/question] [solution] solution: Iodine is important for the thyroid gland to make thyroxin hormone. Thyroxine regulates carbohydrates, proteins and fat metabolism in the body so as to provide the best balance for growth. If iodine is deficient in the diet, thyroxine cannot be produced and the thyroid gland at the neck swells, a condition called goitre. Use of iodized table-salt can provide the required amount of iodine in the diet. ...
How does chemical coordination
[question] Question. How does chemical coordination take place in animals? [/question] [solution] solution: Hormones –They are secretions of the endocrine glands and one of the most important substance that controls the body chemistry, also known as "Chemical messengers." [/solution]...
Design an experiment to demonstrate hydrotropism.
[question] Question. Design an experiment to demonstrate hydrotropism. [/question] [solution] solution: Aim : To demonstrate that root shows hydrotropism. Method Place germinating seeds in moist saw dust contained in a sieve. Observation (i) The radicles pass down and come out of the sieve pores under the influence of gravity. (ii) After some growth, radicles move back and enter the saw dust again. (i) This shows that roots shows both hydrotropic response and geotropic response. (ii) The hydrotr...
How do auxins promote the growth
[question] Question. How do auxins promote the growth of a tendril around a support? [/question] [solution] solution: When the tip of the tendril touches a support, the auxins present on its tip moves to the side of tip which is away from the support, so due to more auxins in its tendrils away from the support grows faster. [/solution]...
Give an example of a plant hormone
[question] Question. Give an example of a plant hormone that promotes growth. [/question] [solution] solution: Auxins [/solution]...
How is the movement of leaves of the sensitive plant different
[question] Question. How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light? [/question] [solution] solution: [/solution]...
What are plant hormones?
[question] Question. What are plant hormones? [/question] [solution] solution: Plant hormones help to coordinate growth, development and response to the environment. They are synthesized in minute quantity in one part of the plant body and simply diffuse to another part, where they influence specific physiological processes. Example Auxins. [/solution]...
What is the role of the brain in reflex action?
[question] Question. What is the role of the brain in reflex action? [/question] [solution] solution: The reflexes which involve only the spinal cord are called spinal reflexes.The spinal reflexes are produced in the spinal cord but the message of reflex action taken also goes to reach the brain where the thinking process occurs. Some reflex arcs involve the brain, rather than the spinal cord only.They are called cerebral reflexes.Closing of eyes, when exposed to flash of light and salivation at...
How do we detect the smell
[question] Question. How do we detect the smell of an agarbatti (incense stick)? [/question] [solution] solution: When agarbatti burns, its pleasant small is detected by the olfactory receptor present inside the nose.The action of smell generate the electrical impluse which are carried to hypothalamus of brain thus we detect the smell of agarbatti. [/solution]...
Which part of the brain maintains posture
[question] Question. Which part of the brain maintains posture and equilibrium of the body? [/question] [solution] solution: Cerebellum. [/solution]...
What happens at the synapse
[question] Question. What happens at the synapse between two neurons ? [/question] [solution] solution: The neurons lie end to end in a chain to transmit the impulses in an animal body. The neurons are not connected. There occurs a very minute gap between terminal portion of axon of one neuron and dendron of the other neuron. This gap is called synapse. At the end of the axon, the electrical impulse sets off the release of some chemicals. These chemicals cross the gap (synapse), and start a simi...
What is the difference between a reflex
[question] Question. What is the difference between a reflex action and walking? [/question] [solution] solution: [/solution]...