Share & grow the world's knowledge!
We want to connect the people who have knowledge to the people who need it, to bring together people with different perspectives so they can understand each other better, and to empower everyone to share their knowledge.
What is the purpose of making urine in the human body? Name the organs that stores and releases the urine.
Urine formation helps in excretion by removing harmful nitrogenous wastes like urea, uric acid, and excess water. This process maintains the body’s chemical balance and prevents accumulation of toxins. Urine is stored in the urinary bladder until excretion, and when the bladder contracts, it is releRead more
Urine formation helps in excretion by removing harmful nitrogenous wastes like urea, uric acid, and excess water. This process maintains the body’s chemical balance and prevents accumulation of toxins. Urine is stored in the urinary bladder until excretion, and when the bladder contracts, it is released out of the body through the urethra. This ensures proper waste removal and homeostasis.
See lessWhy do arteries have thick and elastic walls whereas veins have valves?
Arteries transport blood from the heart under high pressure, so they need thick and elastic walls to resist and maintain this pressure without damage. In contrast, veins carry blood back to the heart at low pressure. To prevent blood from flowing backwards due to gravity, veins are provided with valRead more
Arteries transport blood from the heart under high pressure, so they need thick and elastic walls to resist and maintain this pressure without damage. In contrast, veins carry blood back to the heart at low pressure. To prevent blood from flowing backwards due to gravity, veins are provided with valves. Thus, arteries manage pressure, while veins ensure correct direction of blood flow.
See lessThe refractive indices of three media are given below: A ray of light is travelling from A to B and another ray is travelling from B to C. (a) In which of the two cases the refracted ray bends towards the normal? (b) In which case does the speed of light increase in the second medium? Give reasons for your answer.
(a) When a ray travels from A (refractive index 1.6) to B (1.8), it moves from a rarer to a denser medium. In this case, the speed of light decreases, causing the ray to bend towards the normal. Therefore, the bending towards the normal occurs only in the transition from medium A to medium B. (b) WhRead more
(a) When a ray travels from A (refractive index 1.6) to B (1.8), it moves from a rarer to a denser medium. In this case, the speed of light decreases, causing the ray to bend towards the normal. Therefore, the bending towards the normal occurs only in the transition from medium A to medium B.
(b) When the ray moves from B (refractive index 1.8) to C (1.5), it passes from a denser to a rarer medium. Light travels faster in a medium with lower refractive index. Thus, in medium C, with refractive index 1.5, the speed of light increases compared to medium B, because of the inverse relationship between refractive index and velocity.
See lessAssertion (A): Rusting of Iron is endothermic in nature. Reason (R): As the reaction is slow, the release of heat is barely evident.
Rusting of iron occurs when iron reacts with oxygen and moisture, forming hydrated iron oxide. This reaction is exothermic, though very slow, so heat release is hardly noticed. Therefore, the statement that rusting is endothermic is false, while the reason provided is also incorrect. Thus, the correRead more
Rusting of iron occurs when iron reacts with oxygen and moisture, forming hydrated iron oxide. This reaction is exothermic, though very slow, so heat release is hardly noticed. Therefore, the statement that rusting is endothermic is false, while the reason provided is also incorrect. Thus, the correct answer is C. Assertion is true but Reason is false.
See lessWhich of the following features relates to biodegradable substances? (a) Broken down by biological processes (b) Remain inert (c) Persist in environment for long time (d) May harm the ecosystem
The correct answer is: (a) Broken down by biological processes. Biodegradable substances are materials that can be naturally broken down by bacteria, fungi, or other living organisms into harmless products. Examples include food waste, paper, and leaves. They don’t accumulate in the environment andRead more
The correct answer is: (a) Broken down by biological processes. Biodegradable substances are materials that can be naturally broken down by bacteria, fungi, or other living organisms into harmless products. Examples include food waste, paper, and leaves. They don’t accumulate in the environment and are eco-friendly, unlike non-biodegradable substances that persist and harm ecosystems.
See less