Statements I: In the nephron the descending limb of loop of Henle is impermeable to water and permeable to electrolytes.
Statement II: The proximal convoluted tubule is lined by simple columnar brush border epithelium
and increases the surface area for reabsorption.
In the light of the above statements, choose the
correct answer fropm the options given below:
AI-generated explanation. Check against your textbook.
Explanation:
Statement I is false: the descending limb of the loop of Henle is permeable to water and relatively impermeable to electrolytes; the ascending limb is impermeable to water and actively transports ions. Statement II, in essence, is true: the proximal convoluted tubule is lined by a simple cuboidal epithelium with a brush border (microvilli) that increases the surface area for reabsorption. The exact NCERT phrase emphasizes the brush border and increased reabsorption capacity, though it uses cuboidal rather than columnar wording.
🧠 Did You Know?
Brush border microvilli drastically increase the absorptive surface area, helping reabsorb filtered substances from the tubule into the blood.
💡 NCERT Memory Line:
Proximal convoluted tubule is lined by simple cuboidal epithelium with a brush border to maximize reabsorption.
Regarding catalytic cycle of an enzyme action,
selecte the correct sequential steps:
A. Substrate enzyme complex formation.
B. Free enzyme ready to bind with another
substrate.
C. Release fo products.
D. Chemical bonds of the substrate broken.
E. Substrate bindig to active site.
Choose the correct answer from the options given below:
Statement I: Mitochondria and chloroplasts are both double membrane bound organelles. Statement II: Inner membrane of mitochondria is relatively less permeable, as compared to
chloroplast.
In the light of the above statements, choose the most approriate answer from the options given below:
The type of conservation in which the threatened species are taken out from their natural habitat and placed in special setting where they can be protected and given special care is called:
Tropical regions show greatest level of species richness because:
A. Tropical latitudes have remained relatively undisturbed for millions of years, hence more time was available for species diversification.
B. Tropical environments are more seasonal.
C. More solar energy is available in tropics.
D. Constant environments promote niche specialization.
E. Tropical environments are constant and predictable.
Choose the correct answer from the options given below.