How does chemical coordination take place in animals?
Chemical coordination takes place in animals by the chemical messengers called hormones, which are secreted by the endocrine glands or occurs by the nervous system.
Hypothalamus is the important part in intergrating the nervous and endocrine system.
When endocrine glands secrete hormones, neurosecretory cells are present in the brain which secrets the neurotransmitters. And these chemical messengers get converted into electrical signals and goes into muscles or glands for the movement or for the growth and development of an animal.
Draw the structure of a neuron and explain its function.
Which signals will get disrupted in case of a spinal cord injury?
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?
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?
(i) Write the electron-dot structures for sodium, oxygen and magnesium.
(ii) Show the formation of Na2O and MgO by the transfer of electrons.
(iii) What are the ions present in these compounds?
What is the importance of DNA copying in reproduction?
On the basis of the issues raised in this chapter, what changes would you incorporate in your lifestyle in a move towards a sustainable use of our resources?
What would be the consequences of a deficiency of haemoglobin in our bodies?
Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?
Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and outside the loop.
What processes would you consider essential for maintaining life?
How is the process of pollination different from fertilisation?
What are the components of the transport system in highly organised plants?
What is the function of an earth wire? Why is it necessary to earth metallic appliances?