write a story of an egg and a sperm right through to the development of the enbryo
这是我的science homework,可是我想了好几天也没有想出来..英语好的请帮帮忙哦..!!还有(the egg must be a ambiotic type and contain a diagram..)这个story必须是用英文写的哦..!! 外國的學校..!!我想老師是想我們寫那個孩子形成之前的過程吧..誰幫幫我啊..!!要交了哦..
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回答者：网友
hehe we just have great ambition but there is so many special term, we have no effort to fill the gap between the reality and sciendtific. for the nature procedure, when it comes to talk such topic, on some contend, most of people will consider it as the dirty story. But ,from the large sence, we should get the relatively objectively angle to view such aspect. For you know that , sin the egg and sperm need the nuture combination, we just forcus at the result instead of the process. May, such thoust is not right. Ceratinly, even so, may someone just talk it boudly. you could understand that for life the 's develope, the first start is necessary. Both has great attractive sence, each of tehm is deeply allusion by the other,so that they just get rid of the bindage and hardship. Eventrually, they meet each other , for the god know they are different internal style. For such reason when they combine together ,the miracal take place. There appear the new body. So, more than the word, it is a great precedure. hehe
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其他回答
啊！！！写精子与卵子在子宫里约会的作文啊，你是什么学校的啊？这么无敌
回答者：网友
其他回答
When in the earliest stages of development it is difficult to tell very much about an embryo, including its sex. Ultrasound scans, performed for medical reasons and for sex determination, are seldom done before the 18th week. In fact, at six or seven weeks, all embryos look almost exactly alike -- and not just on the outside. Inside, there are two gonads, which could become testicles or ovaries. And each embryo has two sets of reproductive tubes, one set in case it's a male, and the other for a female. One way to tell from the very beginning if an embryo is male or female is to look at the chromosomes inside one of its cells. A single pair among the 23 total pairs of chromosomes is responsible for determining sex. An embryo with two X chromosomes will develop into a female. An embryo with one X and one Y chromosome will develop into a male. In recent years, geneticists have begun to understand what triggers the development of males as opposed to females. There are only about 30 genes on the Y chromosome. One particularly influential gene is called SRY, or sex-determining region Y gene. This gene seems to be active just once in a male's lifetime -- late in the sixth week of embryonic development -- and in only one place -- the gonad. Despite being active for only a day or two, the SRY gene creates sweeping changes throughout the embryo. According to geneticists who study sex determination, SRY works by attaching itself to other portions of the DNA molecule. In doing so, it distorts the shape of the DNA and sets off a chemical chain reaction. These chemicals turn on other genes, which create scores of proteins and eventually cause the embryo's gonads to become testicles. Not long after, the testicles begin producing the hormone testosterone, which will flow through the embryo throughout development, and cause other changes that ultimately transform it into a male. In the absence of a Y chromosome and its SRY gene, different genes become active. The gonads become ovaries, and without the flood of testosterone, the embryo (a bit less dramatically) becomes female.
回答者：网友
