a) What is the function of our nervous system ?
(b) What are the main organs of the human nervous system ? Draw a labelled diagram to show the main organs of the human nervous system.
(c) How does the human nervous system work ? Explain.
(a) (i) The function of the nervous system is to coordinate the activities of our body. (ii) It helps all other systems of our body to work together. (iii) It receives information from the surroundings, processes it, interprets it and then responds accordingly. (b) The main organs of the nervous system are; brain, spinal cord and nerves.
(c) When the sense organ in our body is affected, it sends the message to the brain in the form of electrical impulses through the sensory neurons. The brain analyses this message and decides the action to be taken. The brain then sends out instructions to the muscles of the concerned body parts through motor nerves and the concerned body part acts accordingly.
What is the function of insulin hormone ? What type of patients are given insulin injections ?
(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) Which plant hormone is present in greater concentration in the areas of rapid cell division?
(b) Give one example of a plant growth promoter and a plant growth inhibitor.
(a) What does a plant root do in response to water ? What is this phenomenon known as ?
(b) What happens to the moonflower (i) during daytime, and (ii) at night ? What is this phenomenon known as ?
(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.
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.
What is the general name of chemical substances which bring about control and coordination in plants ?
Give the scientific terms used to represent the following :
(a) Bending of a shoot towards light.
(b) Growing of roots towards the earth.
(c) Growth of a pollen tube towards ovule.
(d) Bending of roots towards water.
(e) Winding of tendril around a support
Which of the following is a growth movement and which is not ?
(a) folding up of leaves of sensitive plant on touching with hand.
(b) folding up of petals of dandelion flower when light fades.
What is a tendril ? Name the two types of tendrils. What does a tendril do in response to the touch of a support ? What is this phenomenon known as ?
Which halogen element is necessary for the making of thyroxine hormone by the thyroid gland ?
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 the names of all the major endocrine glands present in the human body. Which of these glands also function as exocrine glands ?
Mention one function for each of these hormones:
(a) Thyroxin (b) Insulin (c) Adrenaline (d) Growth hormone (e) Testosterone.
Name various plant hormones. Also give their physiological effects on plant growth and development.
State the structural and the functional unit of the nervous system. Draw its neat labelled diagram and write two functions.
Which organ secretes a hormone when bloo’d sugar rises in our body? Name the hormone and name one enzyme released by this organ.
What is chemotropism? Give one example. Name any two plant hormones and mention their functions.
Name the plant hormones which help/promote (i) cell division (ii) growth of
the stem and roots?
Name one plant hormone that promotes growth and another plant hormone which inhibits growth.
(a) What does a stem (or shoot) do in response to gravity ? What is this phenomenon known as ?
(b) What does a root do in response to light ? What is this phenomenon known as ?