How are involuntary actions and reflex actions different from each other?
Involuntary actions are very quick which is performed by animal without its will or without thinking of the actions but controlled by parts of brain, eg. Heart beating, hand pulling when we touch an hot object.
On the other hand, reflex actions are automatic, result of sudden impulse without any stimulus and it is not controlled by brain .famous eg. - knee jerk (slow strike below the knee cap while sitting with freely hanging legs that kicks the legs forward), yawning, blinking of eyes, sneezing etc.
Draw the structure of a neuron and explain its function.
Which signals will get disrupted in case of a spinal cord injury?
How does chemical coordination take place in animals?
Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.
Why is the use of iodised salt advisable?
The brain is responsible for
(a) thinking.
(b) regulating the heart beat.
(c) balancing the body.
(d) all of the above.
How do we detect the smell of an agarbatti (incense stick)?
How do auxins promote the growth of a tendril around a support?
How does our body respond when adrenaline is secreted into the blood?
Which part of the brain maintains posture and equilibrium of the body?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What changes can you make in your habits to become more environment-friendly?
What is the importance of DNA copying in reproduction?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.
The anther contains
(a) sepals.
(b) ovules.
(c) pistil.
(d) pollen grains.
How do Mendel’s experiments show that traits may be dominant or recessive?
What happens when dilute hydrochloric acid is added to iron fillings? Tick the correct answer.
(a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced.
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
Describe the structure and functioning of nephrons.
Name a mirror that can give an erect and enlarged image of an object.
Why does distilled water not conduct electricity, whereas rain water does?
What chemical process is used for obtaining a metal from its oxide?
List the properties of magnetic field lines.