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猪(2n=38)的性别决定方式为XY型.某地发现一个罕见的睾丸雌性化的猪两性畸形家系.当地居民反映,性畸形猪兼具雌性和雄性的外生殖器,但不具生殖能力,同时发现生长速度比较快,适于肉猪饲养.研究者对家系中的4头母猪的多胎产仔情况进行了统计,数据见表:

亲代母猪编号

F1情况

正常公猪(头)

正常母猪(头)

性畸形猪(头)

1(育6胎)

16

32

15

2(育4胎)

13

22

11

3(育6胎)

18

30

15

4(育7胎)

14

33

16

合计

61

117

57

为确认性畸形性状的变异,研究者进行了如下研究和分析:

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    Are you using a dating App to make friends? How do you know that Ben from London is really 25-year-old? Is his photo taken recently? Is his name even Ben? Dating apps can be tricky to operate, particularly when you're trying to know whether someone is trustworthy, but one thing you can't cheat is your gene, which is why a new dating app is using DNA as a basis for its match.

    A dating app named Pheramor requires all users to hand in a cheek sample, from which a team of in-house scientists using a specially-created tool can queue the specific genes connected with attraction and then identify which users might be suitable. The process works by separating the 11 genes that link to our pheromones(信息素), the chemical signals that are believed to control one's attraction. Combining this data with the personal information allows the app to make very specific matches.

    “Pheramor uses both your biology and your social technology: we collect your genetic data through a cheek sample and collect your like, dislikes, and interest from your social media introductions like Facebook, Twitter, etc,” the app's website explains. “All of them will be used in our specific software, which is designed to learn what you prefer.”

    The co-founder Brittany Barreto, who has a PHD in genetics added that Pheramor's technology digs deeper than traditional dating apps, making it almost impossible for people to cheat their way to a date.

    The Houston-based app is already up and running but hopes to be officially put into market in February with 3,000 members.