Biology · Human Reproduction · NEET
No, they are not the same. Seminal plasma is only the FLUID part, made by the accessory glands (seminal vesicles, prostate, bulbourethral glands). It is rich in fructose, calcium and certain enzymes. Semen is the FULL thing: seminal plasma PLUS the sperms floating in it. NCERT says clearly: 'The seminal plasma along with the sperms constitute the semen.' So semen = seminal plasma + sperms. This one-line difference is a common NEET trap.
For normal fertility: at least 60% of sperms must have normal SHAPE and size, and at least 40% must show vigorous MOTILITY (movement). Students often swap these two numbers. Memory trick: the BIGGER number (60) goes with the fixed feature (shape), the SMALLER number (40) goes with the active feature (motion). NCERT gives these exact figures, so NTA can directly ask 'at least ___% must show vigorous motility'.
The human male ejaculates about 200 to 300 million sperms during one coitus (one ejaculation). This is the NCERT figure. Do not confuse it with '200-300 million sperms produced per day' — the text says released during a coitus. Even though millions are released, only one sperm fertilises the ovum; the huge number improves the chance that some reach and penetrate the egg.
Fructose is a sugar. It acts as an energy source (fuel) for the sperms so they can swim actively. Sperms need energy for motility, and their own mitochondria in the middle piece use this fructose to make ATP. Seminal plasma also has calcium and enzymes. The bulbourethral gland secretion additionally helps lubricate the penis. NEET can ask which component provides energy — answer: fructose.
No. Sperms alone are just gametes. They must be mixed with the seminal plasma (the glandular fluid) to form semen. Sperms are made in the seminiferous tubules of the testis; the fluid is added later by the accessory glands as the sperms pass through the ducts. Only the mixture is called semen.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Semen is composed of seminal plasma plus sperms. The seminal plasma (fluid from seminal vesicles, prostate and bulbourethral glands) is rich in fructose, calcium and certain enzymes.
During one coitus, about 200 to 300 million sperms are ejaculated. For normal fertility at least 60% must have normal shape and size and at least 40% must show vigorous motility.
Fructose is a sugar that serves as an energy source for the sperms, helping them stay motile so they can swim toward the ovum.
Seminal plasma is only the fluid part (fructose, calcium, enzymes). Semen is seminal plasma together with the sperms.
The paired seminal vesicles, the prostate and the paired bulbourethral glands. Bulbourethral gland secretion also lubricates the penis.
