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 are the components of the transport system in highly organised plants?
What would be the consequences of a deficiency of haemoglobin in our bodies?
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?
Why does the sky appear dark instead of blue to an astronaut?
Give an example of characteristics being used to determine how close two species are in evolutionary terms.
A concave mirror produces three times magnified (enlarged) real image of an object placed at 10 cm in front of it. Where is the image located?
List the properties of magnetic field lines.
Why does a compass needle get deflected when brought near a bar magnet?
Which gas is usually liberated when an acid reacts with a metal? Illustrate with an example. How will you test for the presence of this gas?
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?
Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be –
(a) 1:2 (b) 2:1 (c) 1:4 (d) 4:1
How are the modes for reproduction different in unicellular and multicellular organisms?
Why are traits acquired during the life-time of an individual not inherited?