Question

1. Answer the following questions:
   1. Why do you suppose males produce so many millions of sperm with each ejaculation?
      
      
      
   2. Note that the vas deferens (also called ductus deferens) is a tube nearly 30 cm (12 inches) in length! Why should it be so long? Can you imagine a “shortcut” that would make it shorter and perhaps more efficient?
      
      
      
   3. Does it seem strange to you that the urethra from the urinary bladder joins the ejaculatory duct and then creates one tube (the prostatic urethra and the penile urethra) that at times carries urine and at other times carries semen? Does this seem like bad plumbing to you? Explain your thoughts.
      

Answer 1

Question 1

Each time a man ejaculates approximately 50 million sperms are released. During intercourse adult, the man ejaculates sperm in the female reproductive tract out of 50 million sperms approximately only 1 million sperms make their way to the uterus due to backflow, acidic pH, phagocytosis by macrophages (as sperm as foreign cells they are phagocytosed by the macrophages in the cervix and vagina), some of them even get trapped in the mucus present secretions present in the cervix.

Therefore due to above all reason now the number of viable sperms reduces to thousand and only a few of them make their way to reach the fallopian tube where the ovum is available for fertilization, There are two fallopian tubes and two ovaries present in the female they produce eggs simultaneously one by one alternative. So a thousand of sperm proceed towards the fallopian tube eager to fertilize the ovum some of them enter the wrong fallopian tube and miss there golden opportunity to fertilize the ovum, This reduces the number of eligible/ viable sperms to hundreds only approximately 200-400 sperms reach the fallopian tube where the egg is available for fertilization. The sperm is regarded as a cheap gamete and has a limited source of energy so most of the sperm exhaust their energy while swimming.

Finally out of millions of sperms ejaculated by the man only one fertilizes the ovum and forms the zygote hence the nature produces large number of male gametes in order to increase the chance of fertilization.