问题 选择题

我国婚姻法禁止近亲结婚,其原因是(  )

A.基因差别大,易患传染病

B.相同的基因多,后代易患遗传病

C.近亲结婚者,多发传染病

D.近亲结婚,后代的基因易变异

答案

近亲是指直系血亲和三代以内的旁系血亲.我国婚姻法已明确规定,禁止直系血亲和三代以内的旁系血亲结婚.原因是近亲带有相同隐性遗传致病基因的可能性较大,近亲结婚所生的孩子患有遗传病的机率大,如近亲结婚时所生的子女中,单基因隐性遗传病的发病率比非近亲结婚要高出7.8~62.5倍;先天畸形及死产的机率比一般群体要高3~4倍.孩子智力下降,并患有许多先天性疾病如先天愚型病,其危害十分显著.因此禁止近亲结婚可以减少后代得遗传病的可能性.可见B符合题意.

故选:B

问答题

The primitive root of the pleasure of parenthood is two-fold. (46) On the one hand, there is the feeling of part of one’s own body externalized, prolonging its life beyond the death of the rest of one’s body, and possibly in its turn externalizing part of itself in the same fashion, and so securing the immortality of the germ plasma. On the other hand there is an intimate blend of power and tenderness. The new creature is helpless, and there is an impulse to supply its needs, an impulse which gratifies not only the parent’s love towards the child, but also the parent’s desire for power. (47) So long as the infant is felt to be helpless, the affection which is bestowed upon it does not feel unselfish, since it is in the nature of protection to a vulnerable portion of oneself.

(48) But from a very early age there comes to be a conflict between love of parental power and desire for the child’s good, for, while power over the child is to a certain extent decreed by the nature of things, it is nevertheless desirable that the child should as soon as possible learn to be independent in as many ways as possible, which is unpleasant to the power impulse in a parent. Some parents never become conscious of this conflict, and remain tyrants until the children are in a position to rebel. Others, however, become conscious of it, and thus find themselves a prey to conflicting emotions. In this conflict their parental happiness is lost. (49) After all the care that they have bestowed on the child, they find to their mortification that he turns out quite different from what they had hoped. They wanted him to be a soldier, and they find him a pacifist, or, like Tolstoy, they wanted him to be a pacifist, and he joins the Black Hundreds.

But it is not only in these later developments that the difficulty is felt. (50) If you feed an infant who is already capable of feeding himself, you are putting love of power before the child’s welfare, although it seems to you that you are only been kind in saving him trouble. If you make him too vividly aware of dangers, you are probably actuated by a desire to keep him dependent upon you. If you give him demonstrative affection to which you expect a response, you are probably endeavoring to grapple him to you by means of his emotions. In a thousand ways, great and small, the possessive impulse of parents will lead them astray, unless they are very watchful or very pure in heart.

(49) After all the care that they have bestowed on the child, they find to their mortification that he turns out quite different from what they had hoped

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