题目

单词拼写 (1) Unlike traditional park,(主题) parks often want to teach visitors something. (2) What will this mean for (传统的) books and magazines? (3) This is another (熟悉的) and strange feature of this poem. (4) Today many people in the urban area are experiencing the joy of the (娱乐) park for the first time. (5) When in conferences, he often leaves for (各种各样的) reasons.17.哺乳动物的生殖活动与光照周期有着密切联系.如图表示了光暗信号通过视网膜→松果体途径对雄性动物生殖的调控.请据图回答:(1)光暗信号调节的反射弧中,效应器由传出神经末梢和松果体组成,兴奋在传入神经纤维上的传导是单向的(选填“单向的”或“双向的”).(2)图中去甲肾上腺激素释放体现了生物膜的流动性,该过程中伴随的信号转变是电信号→化学信号.(3)褪黑素通过影响HPG轴发挥调节作用,该过程属于体液(或激素)调节,在HPG轴中,促性腺激素释放激素(GnRH)作用于垂体,促使其分泌黄体生成素(LH,一种促激素);LH随血液运输到睾丸,促使其增加雄激素的合成和分泌.(3)若给正常雄性哺乳动物个体静脉注射一定剂量的LH,随后其血液中GnRH水平会降低,原因是LH促进雄激素的分泌,雄激素抑制下丘脑分泌GnRH.
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