Why should men be ambitious and aggressive?男士为什么要努力？

Today I am gonna to present one of the answers ,from the perspectives of biology and physiology such as ovulation(forming an egg) and fertilization (egg fertilized by sperm), to the questions:

Why are females so critical and why should men be ambitious and aggressive?

Let's study the structure of human sperm, please refer to Figure 1. below.

Figure 1-1. Structure of human sperm

Figure 1-2. Structure of human sperm

The most important part of human sperm is the acrosome which contains enzymes that digest the zona pellucida around the egg. In Figure 2. Structure of a mature human egg, we can find the function of zona pellucida of human egg is that it protects egg cell and RESTRICTs entry of sperm. 

Here is the point.

The zona pellucida's restriction of entry of sperm is to prevent ANOTHER sperm to come into the egg if the egg has been fertilized, or one sperm has come into the egg. This fertilized sperm is so LUCKY. Congrats!

Again please refer to Figure 2, you can find cortical granules which are particles like guards standing in a circle within the zona pellucida to harden the zona pellucida to prevent multiple fertilization. Below is the mechanism:

cortical granules move to the plasma membrane of the egg and fuse with it, releasing their contents by exocytosis. Enzymes from the cortical granules cause cross- linking of glycoproteins in the zona pellucida, making it hard and preventing polyspermy. (Please refer to Figure 3, corticle reaction)

Consequently ONE egg is fertilized by ONE sperm, not two or more, generally speaking.

Figure 2-1. Structure of a mature human egg

Figure 2-2. Structure of a mature human egg

Figure 3-1. Stages of the fertilization of human egg

Figure 3-2. Stages of the fertilization of human egg

We can with a piece of cake recognize the truth that in the beginning of life - zygote,  there is some kind of reflection of the true reality all around the corner of the world, that female is critical to choose her ideal dating or marriage male partner。 

 Another toilless common sense is that in every 28-day menstruation period, there is ONLY ONE egg ovulated; while  one ejaculation for an ordinary man will release millions of sperm each day from puberty onwards. The amount difference between egg ovulation and sperm formation is HUGE.

It is no doubt that man should work hard for wooing his ideal dating girl. 

Come on, man! 

 Go! Go! Go!

Add oil! 

Add oil! 

Add oil! 

（Add oil has been collected into Oxford English Dictionary! Bravo! ）

*****Feel free to consult VMJ for IB and AP biology,
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