What is a phytohormone? Name any two phytohormones.
Phytohormones are chemical substances, which are produced naturally in plants and are capable of translocation and regulating one or more physiological reactions when present in appropriate concentrations. The two phytohormones are auxins and gibberellins.
(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.
What is the function of insulin hormone ? What type of patients are given insulin injections ?
(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 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 ?
(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 ?
Which halogen element is necessary for the making of thyroxine hormone by the thyroid gland ?
(a) Name the structural and functional unit of nervous system.
(b) Draw a flow chart to show the classification of nervous system into various parts.
(c) What is autonomic nervous system ? What is its function ?
(d) What is voluntary nervous system ? Explain the working of voluntary nervous system with an example.
State the functions of the following hormones :
(a) Thyroxine (b) Adrenaline (c) Growth hormone
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.
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
a) What are the short fibres of a neuron known as ?
What is the long fibre of a neuron 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 ?
What is chemotropism? Give one example. Name any two plant hormones and mention their functions.
Name and explain the function of the hormone secreted by the pituitary gland in humans.
Name the plant hormones which help/promote (i) cell division (ii) growth of
the stem and roots?
What is the general name of chemical substances which bring about control and coordination in plants ?
Give one example of the movement of a plant part which is caused by the loss of water (or migration of water).
(a) What does a Mimosa pudica plant do in response to touch ? What is this phenomenon known as ?
(b) What happens to the dandelion flower (z) during daytime, and (ii) at night ? What is this phenomenon known as ?
Distinguish between tropic movements and nastic movements in plants. Give examples to illustrate your answer.
Name one gland each :
(a) which acts only as an endocrine gland.
(b) which acts only as an exocrine gland.
(c) which acts both as an endocrine gland as well as an gxocrine 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
Explain the difference between each of the following pairs of terms :
(a) receptor and effector (b) cerebrum and cerebellum
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.
Why is the flow of signals in a synapse from axonal end of one neuron to dendritic end of another neuron but not the reverse?