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?
Write an equation to show the reaction between Plaster of Paris and water.
What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.
Can the wing of a butterfly and the wing of a bat be considered homologous organs? Why or why not?
Under what soil condition do you think a farmer would treat the soil of his fields with quick lime (calcium oxide) or slaked lime (calcium hydroxide) or chalk (calcium carbonate)?
When does an electric short circuit occur?
What are the environmental consequences of the increasing demand for energy? What steps would you suggest to reduce energy consumption?
The anther contains
(a) sepals.
(b) ovules.
(c) pistil.
(d) pollen grains.
What is the common name of the compound CaOCl2?
A spherical mirror and a thin spherical lens have each a focal length of –15 cm. The mirror and the lens are likely to be
(a) both concave.
(b) both convex.
(c) the mirror is concave and the lens is convex.
(d) the mirror is convex, but the lens is concave.
Explain the importance of fossils in deciding evolutionary relationships.