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?
Which part of the brain maintains posture and equilibrium of the body?
How does our body respond when adrenaline is secreted into the blood?
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?
Describe the structure and functioning of nephrons.
What are the components of the transport system in human beings? What are the functions of these components?
Give an example of a double displacement reaction other than the one given in activity 1.10.
A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny all bore violet flowers, but almost half of them were short. This suggests that the genetic make-up of the tall parent can be depicted as
(a) TTWW
(b) TTww
(c) TtWW
(d) TtWw
A solution turns red litmus blue, its pH is likely to be
(a) 1 (b) 4 (c) 5 (d) 10
Why does distilled water not conduct electricity, whereas rain water does?
What would be the electron dot structure of carbon dioxide which has the formula CO2?
Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.
What chemical process is used for obtaining a metal from its oxide?
Name the substance which on treatment with chlorine yields bleaching powder.