Question

The rate of active movement of sperms is
A. 1.5-3.0 cm/min
B. 1.5-3.0 mm/min
C. 1.5-3.0 m/min
D. 1.5-3.0 m/hr

Answer 1

Hint: During intercourse, a man ejaculates about 300 million sperms. After the sperms reach the female reproductive tract, they move very actively.

Complete solution:
Sperms are able to swim (in a fluid medium) because they have a tail.
Out of millions of sperms, few sperms are able to swim through the uterus and reach the fallopian tube. The rate of active movement of sperms is about 1.5 to 3.0 mm/min.
The sperm (along with seminal plasma) is a part of semen. This semen is released from the penis after ejaculation.
The egg (or ovum) sends a chemical signal called progesterone which is why the sperms become more active. This happens so that the sperm could penetrate inside the egg and successfully fertilize.
While passing through the cervix many sperms with poor motility and morphology are filtered due to the presence of cervical mucus. So only a few of the sperms (as compared to the number of sperms after the ejaculation) reach the uterus.
After the sperms enter the uterus, contractions of the uterus help the sperm to move upwards to the fallopian tube.
The first few sperms that enter the fallopian tube are not always likely to fertilize with the egg.
The motile sperm can survive up to 5 days in the female reproductive tract. So there may be still a chance that the surviving sperm can fertilize the egg.

So the correct answer is option B.

Note: The middle piece of sperm consists of a number of mitochondria which provides energy for the movement of the tail of sperm which is very important for fertilization.