List I | List II | ||
A. | Non-medicated IUD | I. | Multiload 375 |
B. | Copper releasing IUD | II. | Progestogens |
C. | Hormone releasing IUD | III. | Lipper loop |
D. | Implants | IV. | LNG-20 |
A block of certain mass is placed on a rough floor. The coefficients of static and kinetic friction between the block and the floor are 0.4 and 0.25 respectively. A constant horizontal force \( F = 20 \, \text{N} \) acts on it so that the velocity of the block varies with time according to the following graph. The mass of the block is nearly (Take \( g = 10 \, \text{m/s}^2 \)):
A wooden block of mass M lies on a rough floor. Another wooden block of the same mass is hanging from the point O through strings as shown in the figure. To achieve equilibrium, the coefficient of static friction between the block on the floor and the floor itself is
The circuit shown in the figure contains two ideal diodes \( D_1 \) and \( D_2 \). If a cell of emf 3V and negligible internal resistance is connected as shown, then the current through \( 70 \, \Omega \) resistance (in amperes) is:
The mechanism of hormone action is categorised into two classes:
This type of mechanism is represented by the water-soluble hormones that are amines or proteins in the composition like the growth hormone, oxytocin, ADH, etc. These hormones cannot pass via the lipid membrane. They have their earmark receptor on the cell membrane to which the hormone binds. When the hormone sticks or binds to the specific target receptor, the enzyme adenyl cyclase in the cell membrane is charged. This aids in the production of cyclic AMP. cAMP behaves as the secondary messenger. It diffuses through the cell membrane and activates various enzymatic reactions to cause biochemical changes. The target cell acknowledges these changes and cAMP is deactivated by the enzyme phosphodiesterase.
This type of mechanism is represented by lipid-soluble hormones like fatty acids and steroids that can pass very easily through the plasma membrane. They own intracellular receptors. The hormones stick or bind to the target receptor that activates the enzymatic activity of the cell to bring regard to biochemical changes. Transcription of DNA begins with the hormone-receptor complex. The mRNA is transferred into protein. This protein is the source of biochemical changes inside the cell.