How is the amount of urine produced regulated?
Urine is the fluid and the dissolved waste materials which are excreted out by the kidney. Urine formation involves three processes:
When the amount of water or any fluid get increased above the normal amount, then ultrafiltration process will be increase due to increase in blood pressure of the glomerulus. Then this sends the signal to the brain or the hypothalamus to stop the release of the hormone vasopressin or antidiuretic hormone (ADH) which automatically helps in the regulation of the amount of the urine. ADH hormone deficiency slows down the permeability of the cells of the distal convoluted tubule and collecting duct that decrease reabsorption of water. This more filtration and less reabsorption produce dilute urine and then finally, the amount of urine get back into the normal state. That is how the amount of urine produced is regulated.
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
What criteria do we use to decide whether something is alive?
What are the different ways in which glucose is oxidised to provide energy in various organisms?
The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm. (c) chloroplast.
(b) mitochondria. (d) nucleus.
What are the differences between autotrophic nutrition and heterotrophic nutrition?
What are outside raw materials used for by an organism?
What would be the consequences of a deficiency of haemoglobin in our bodies?
What are the components of the transport system in highly organised plants?
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
Where do plants get each of the raw materials required for photosynthesis?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
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 difference between a reflex action and walking?
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?
List two methods of producing magnetic fields.
Compare the power used in the 2 Ω resistor in each of the following circuits:
(i) a 6 V battery in series with 1 Ω and 2 Ω resistors, and (ii) a 4 V battery in parallel with 12 Ω and 2 Ω resistors.
What are oxidising agents?
What are plant hormones?
The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?
Why do HCl, HNO3, etc., show acidic characters in aqueous solutions while solutions of compounds like alcohol and glucose do not show acidic character?
Two lamps, one rated 100 W at 220 V, and the other 60 W at 220 V, are connected in parallel to electric mains supply. What current is drawn from the line if the supply voltage is 220 V?
Which of the following terms does not represent electrical power in a circuit?
(a) I2R (b) IR2 (c) VI (d) V2/R
What are the environmental consequences of the increasing demand for energy? What steps would you suggest to reduce energy consumption?
Which of the following is not an example of a bio-mass energy source?
(a) wood (b) gobar-gas
(c) nuclear energy (d) coal