(a) Name two systems which taken together perform the functions of control and coordination in human beings.
(b) What does the central nervous system in humans consist of ? What is the job of the central nervous system ?
(c) Give the various functions of brain.
(a) Nervous system and endocrine system.
(b) The central nervous system consists of the brain and spinal cord. The work of the CNS is to direct incoming messages to the motor neurons that are connected to the part of the body which will respond to a stimulus. It is involved in complicated responses where both (brain and spinal cord) work. It enables a person to give a more appropriate and more intelligent response to various situations.
(c)
(i) The brain receives information carrying nerve impulses from all the sensory organs of the body.
(ii) It responds to the impulses brought in by sensory organs by sending its own instructions through motor nerves to the muscles and glands causing them to function accordingly.
(iii) It correlates the various stimuli from different sense organs and produces the most appropriate and intelligent response.
(iv) It coordinates the body activities so that the mechanisms and chemical reactions of the body work together efficiently.
(v) It stores information so that behavior can be modified according to the past experience.
(i) Name the hormones that are released in human males and females when they reach puberty.
(ii) Name a gland associated with brain. Which problem is caused due to the deficiency of the hormone released by this gland ?
What is the stimulus in : (a) phototropism ? (b) geotropism ? (c) chemotropism ? (d) hydrotropism ? (e) thigmotropism ?
What does CNS stand for ? Which part of CNS : (a) consists of two cerebral hemispheres, and (b) has spinal nerves attached to it ?
When you smell a favourite food your mouth begins to water (that is, you secrete saliva). Write down what the following are examples of :
(a) the smell of the food
(b) the cells in your nasal passages which perceive the smell
(c) the gland which is stimulated to secrete saliva.
What are 'hormones'? State one function of each of the following hormones:
(i) Thyroxine (ii) Insulin
(a) The human brain can be broadly divided into three regions. Name these three regions.
(b) What is cranium ? What is its function ?
(a) Define phototropism. Give one example of phototropism.
(b) How does phototropism occur in a plant stem (or shoot) ? Explain with the help of labelled diagrams.
(c) What is meant by positive phototropism and negative phototropism ? Give one example of each type.
Which one term in each of the following includes the other three ?
(a) thyroid, ductless gland, thymus, pituitary, ovary
(b) adrenalin, insulin, hormone, thyroxine, estrogen
Write one example each of the following tropic movements :
(i) Positive phototropism (ii) Negative phototropism
(iii) Positive geotropism (iv) Negative geotropism
(v) Hydrotropism (vi) Chemotropism
Name and explain the function of the hormone secreted by the pituitary gland in humans.
Mention one function for each of these hormones:
(a) Thyroxin (b) Insulin (c) Adrenaline (d) Growth hormone (e) Testosterone.
(a) Explain how auxins help in bending of plant stem towards light.
(b) State the objective of the experiment for which experimental set-up is shown in the given diagram.
A potted plant is made to lie horizontally on the ground. Which part of the plant will show
(i) positive geotropism?
(ii) negative geotropism?
Name the plant part :
(a) which bends in the direction of gravity but away from light
(b) which bends towards light but away from the force of gravity
(a) Write the names of the regions in hindbrain. Give one function of each region.
(b) Name the functions of cerebrum.
What are meanings? What are their functions? Name the fluid, which is filled in between meanings.
(a) Name the hormone which is released into the blood when its sugar level rises. Explain the need of Chemical communication in multicellular organisms the organ which produces this hormone and its effect on blood sugar level. Also mention the digestive enzymes secreted by this organ with one function of each.
(b) Explain the need of Chemical communication in multicellular organisms.
Give one example each of a plant part:
(a) which is positively hydrotropic as well as positively geotropic.
(b) which is positively phototropic but negatively geotropic.
(a) What are the various sense organs in our body ?
(b) What is meant by receptors and effectors ? Give two examples of each.
(a) Name the hormones secreted by the following endocrine glands :
(i) Thyroid gland (ii) Parathyroid glands (iii) Pancreas (iv) Adrenal glands
(b) Write the functions of testosterone and oestrogen hormones.
(a) What is a reflex action ? Explain with the help of an example.
(b) Define reflex arc. Give the flow chart of a spinal reflex arc.
(c) How are involuntary actions and reflex actions different from each other ?
(a) How is brain protected from injury and shock?
(b) Name two main parts of hind brain and state the functions of each.
State the functions of any three of the structural and functional unit of nervous system.
Name, the two main organs of our central nervous system. Which one of them plays a major role in sending command to muscles to act without involving thinking process? Name the phenomenon involved.