Quoted from: Adrenal Glands:
In mammals, the adrenal glands (also known as suprarenal glands) are endocrine glands that sit atop the kidneys; in humans, the right suprarenal gland is triangular shaped, while the left suprarenal gland is semilunar shaped. They are chiefly responsible for releasing hormones in response to stress through the synthesis of corticosteroids such as cortisol and catecholamines such as epinephrine. The adrenal glands affect kidney function through the secretion of aldosterone, a hormone involved in regulating the osmolarity of blood plasma. 
- Multiplication phase
- Growth phase
- Maturation phase
- Metamorphosis of spermatid
ALLAH mentions clearly that he created pairs: Male and Female from the “nurfah” Sperm:
And that He (Allâh) creates the pairs, male and female. (45) From Nutfah (drop of Semen) when it is emitted. (53: 46)
ALLAH explains the gender of child whether male or female comes early from the sperm (nutfa), and this to refute the ancient bad traditions that put the responsibility of child gender on the Mother’s account, and to show them that “sperm” is the responsible one which comes from man, of course.
Inside each testis is a network of fine-diameter tubes called seminiferous tubules. Sertoli cells form the walls of a seminiferous tubule. Sertoli cells nourish, support, and protect developing germ cells, which undergo cell division by meiosis to form spermatozoa (immature sperm). During spermatogenesis, germ cells begin near the wall of a seminiferous tubule, and after division they are shed into the tubule. Proteins produced by Sertoli cells are required for spermatogenesis, as is testosterone .
As explained above there is a storage place for the sperms inside testes which is called seminiferous tubule that stores the sperms for a period of weeks .
This fact is mentioned in the following verse:
It is He Who has created you from a single person (Adam), and has given you a place of residing (on the earth or in your mother's wombs) and a place of storage [in the earth (in your graves) or in your father's loins]. Indeed, We have explained in detail Our revelations (this Qur'ân) for people who understand. (6:98)
Quoted from: How sperm find their way?
he life of a sea urchin sperm is a difficult one. Once ejaculated, the cells have to navigate turbulent seas, with their eddies and currents, to fertilise a sea urchin egg. So how do they know where to go? They follow their chemical ‘noses’, so to speak.
In the sperm’s case, they orientate themselves by following the trail of a chemoattractant produced by the egg: the higher the concentration of the molecule, the closer they are to their goal. 
Quoted from: How Human Reproduction Works?
The lucky few sperm who reached the egg in the Fallopian tube surround it and begin competing for entrance. The head of each sperm, the acrosome, releases enzymes that begin to break down the outer, jelly-like layer of the egg's membrane, trying to penetrate the egg. Once a single sperm has penetrated, the cell membrane of the egg changes its electrical characteristics. This electrical signal causes small sacs just beneath the membrane (cortical granules) to dump their contents into the space surrounding the egg. The contents swell, pushing the other sperm far away from the egg in a process called cortical reaction. The cortical reaction ensures that only one sperm fertilizes the egg. The other sperm die within 48 hours. 
Quoted from: What is early pregnancy failure?
Early pregnancy failure (also known as blighted ovum or anembryonic gestation) is a common cause of miscarriage. It happens when a fertilized egg implants in the uterus but the resulting embryo either stops developing very early or doesn't form at all. If you have an early pregnancy failure, you may not find out about it until the end of your first trimester. 
In the above scientific explanation and as shown in the next image :
- The egg emits certain chemicals that guide the sperms to find their way to the egg.
- Then when a sperm reaches the egg, it throws its nucleus inside the egg, and the sperm eventually die.
- The fertilized egg could survive and start developing or it could die and what is called early pregnancy failure.
From what thing did He create him? (18) From Nutfah (male and female semen drops) He created him, and then set him in due proportion; (19) Then He makes the Path easy for him; (20) Then He causes him to die, and
Some may say it’s talking about the “Human” not the sperm, but if we compare them with Sperm life it matches perfectly:
Verse 19: Human is created from a “Nutfah” , which means a single drop of semen, i.e. one Sperm only.
Verse 20: Then the path make it easy for him !!, Muslim Scholars thought it may means that is the way when the baby is delivered from his mother uterus, but the verse clearly saying that the way is making easy for him, in delivery, it’s not the way that is guiding the baby out but the uterus is pushing him out, but for sperms, it matches perfectly as the chemical path, caused by the egg, is really guiding the sperm and making it easy for him to reach the egg.
Verse 21: Causing him to die and buried him, it may match human’s end of life, but also the sperm when it reaches the egg, it buries it’s nucleus inside the egg, then it dies outside the egg, as shown in next image.
Verse 22: Then, when it is His Will, He makes it strong (Ansharah), some explained that work “Ansharah” as resurrect him again, although it means too “to make it strong”, and this matches that the new fertilized egg may grow and may not and cause early pregnancy failure.
Verses 23-32: talking about human work in life and his food creation too.
Verses 33-42: talking about the Day of resurrection.
Therefore, it’s highly possible that verses 19-22 are talking about Human development and not his life and death, as it will come in further verses again.
7- Sperms & Egg Colors
Each DNA strand wraps around groups of small protein molecules called histones, forming a series of bead-like structures, called nucleosomes, connected by the DNA strand (as illustrated in Figure 1). Under the microscope, uncondensed chromatin has a "beads on a string" appearance. The string of nucleosomes, already compacted by a factor of six, is then coiled into an even denser structure known as a solenoid that compacts the DNA by a factor of 40. The solenoid structure then coils to form a hollow tube. This complex compression and structuring of DNA serves several functions. The overall negative charge of the DNA is neutralized by the positive charge of the histone molecules, the DNA takes up much less space, and inactive DNA can be folded into inaccessible locations until it is needed. 
- Bones marrows produce blood cells (Red, White, platelets).
- Blood is supplied inside the testes and reaches the blood-testes barrier.
- Outside the barrier, blood form the first version of germ cells
- Germ cells traverse the blood-testes barrier and become primary spermatocytes (46 Chromosomes).
- Primary cells divided into 2 x Secondary Spermatocytes of 23 Chromosomes each.
- Secondary Spermatocytes change to Spermatid cells, which finally becomes Sperms.
- When a sperm reaches the egg and it causes pregnancy.
- If all was successful, it develops a new born child: Son or Daughter.
Quoted from: Meisosis
- Eat red meat and bananas, also peaches are recommended.
- Eat salty snacks such as: crackers and chips (but do not over do the salt).
- Nuts, hazelnuts, pecans and almonds are high in Potassium.
- Dads should drink plenty of sodas, preferably cola drinks.
If you want a girl:
- Eat lots of fresh fish, fruit and vegetables.
- Green vegetables such as spinach and broccoli are good sources of magnesium.
- Dairy products, milk, yogurt and cheese are calcium rich.
- Eat Pumkin seeds, Sunflower seeds and Sesame seeds. 
He (the jew) said: I have come to ask you about a thing which no one amongst the people on the earth knows except an apostle or one or two men besides him. He (the Holy prophet) said: Would it benefit you if I tell you that? He (the jew) said: I would lend ears to that. He then said: I have come to ask you about the child. He (the Holy prophet) said: The reproductive substance of man is white and that of woman yellow, and when they have sexual intercourse and the male's substance prevails upon the female's substance, it is the male child that is created by Allah's Decree, and when the substance of the female prevails upon the substance contributed by the male, a female child is formed by the Decree of Allah. The jew said: What you have said is true; verily you are an Apostle. He then returned and went away. The Messenger of Allah (may peace be upon him) said: He asked me about such and such things of which I have had no knowledge till Allah gave me that. (Sahih Muslim, Book #003, Hadith #0614)
- Men with the first combination, known as mm, produce more Y sperm and have more sons.
- The second, known as mf, produce a roughly equal number of X and Y sperm and have an approximately equal number of sons and daughters.
- The third, known as ff, produce more X sperm and have more daughters.