In semen banks, semen is preserved at low temperature using which cryo protectant:-
**Core Concept**
The preservation of semen at low temperatures in semen banks requires the use of cryoprotectants to prevent ice crystal formation and maintain the viability of spermatozoa. Cryoprotectants are substances that inhibit the formation of ice crystals during the freezing process, thereby protecting the sperm cells from damage.
**Why the Correct Answer is Right**
The correct answer is glycerol, which is a widely used cryoprotectant in semen banking. Glycerol works by penetrating the cell membrane and replacing the water inside the cells, thereby preventing the formation of ice crystals during the freezing process. This helps to maintain the integrity and motility of the spermatozoa. Glycerol is also effective in preventing the dehydrating effect of the freezing process, which can cause damage to the sperm cells.
**Why Each Wrong Option is Incorrect**
**Option A:** Dimethyl sulfoxide (DMSO) is another cryoprotectant used in cryopreservation, but it is not as commonly used as glycerol in semen banking due to its potential toxicity and side effects.
**Option B:** Ethylene glycol is a cryoprotectant used in some cryopreservation applications, but it is not typically used in semen banking due to its toxicity and potential for causing damage to sperm cells.
**Option C:** Sucrose is a cryoprotectant used in some applications, but it is not commonly used in semen banking due to its potential to cause osmotic stress and damage to sperm cells.
**Clinical Pearl / High-Yield Fact**
It is essential to note that the choice of cryoprotectant can affect the viability and motility of spermatozoa after thawing. Glycerol is generally considered the most effective cryoprotectant for semen banking due to its ability to maintain sperm motility and integrity.
**Correct Answer: C. Glycerol**