Capacitation is a key physiological process that prepares sperm for fertilization by dissolving the glycoprotein layer over the acrosome. The correct answer to Q.75 is the first option.

Question Breakdown

Capacitation occurs in the female reproductive tract after ejaculation, enabling sperm to undergo the acrosome reaction and fertilize the egg.

Option Analysis

• Glycoprotein layer over the acrosome is dissolved: Correct. This removes stabilizing proteins and cholesterol from the sperm head, increasing membrane fluidity for the acrosome reaction.

• Sperm penetrates the zona pellucida: Incorrect. Penetration follows capacitation and acrosome reaction, not capacitation itself.

• Tail of the sperm is activated: Partially related but wrong. Capacitation leads to hyperactivated tail motility as a side effect, but the core process targets the head.

• Tail of the sperm is inactivated: Incorrect. Sperm motility increases, not decreases, during capacitation.​

Introduction to Capacitation

The capacitation process in sperm is essential for fertilization, occurring in the female tract where the glycoprotein layer over the acrosome dissolves. This prepares sperm for egg penetration, a key topic in biology exams like GATE Life Sciences.

What Happens in Capacitation

Capacitation involves membrane changes like cholesterol efflux and ion shifts, boosting fluidity and pH. It triggers hyperactivated motility and sets up the acrosome reaction without direct penetration.

Key steps include:

• Protein/glycoprotein removal from acrosome.

• Bicarbonate influx for alkalinization.

• Calcium rise for signaling.​

Common Misconceptions

Many confuse capacitation with zona pellucida penetration or tail activation alone. Tail changes support motility, but glycoprotein dissolution defines the process.

Relevance for GATE Life Sciences

This MCQ tests reproductive biology basics. Focus on capacitation as pre-acrosome prep for exams.​