How do we detect the smell of an agarbatti (incense stick)?
When we lighted an incense stick, then its fragnance diffuses and reaches our nose. which is detected by olfactory receptors. Then, through the sensory neurons these receptors goes in the special part of the brain, i.e, fore- brain :- detect the smell (where it is already stored as a memory), and converts in the form of electrical signals.
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 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?
What is the need for a system of control and coordination in an organism?
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?
What would be the consequences of a deficiency of haemoglobin in our bodies?
Draw a labelled diagram of the longitudinal section of a flower.
The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm. (c) chloroplast.
(b) mitochondria. (d) nucleus.
How is the concentration of hydronium ions (H3O+) affected when a solution of an acid is diluted?
Name the sodium compound which is used for softening hard water.
How does the embryo get nourishment inside the mother’s body?
An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. Draw the ray diagram and find the position, size and the nature of the image formed.
Why is sodium kept immersed in kerosene oil?
Why do you think that there should be equitable distribution of resources? What forces would be working against an equitable distribution of our resources?
What are alloys?