OET PRACTI STUDY MATERIALS AND WRITING SKILLS EBOOK PDF
OET Practice Reading Test : -Venus and Mars collide There is one reading passage in this test. After the passage, you will find a number of questions or unfinished statements about the passage, each with four suggested answers or ways of finishing You must choose the one which you think fits best, i.e. the best answer. Answer all questions.
We have learned a great deal about the biology that underpins sex differences. For years, the accepted view was that all embryos start out the same-the default sex being female. Then during the first trimester, in individuals that have inherited a Y chromosome, a gene called sry, for sex determining region Y, switches on the development of the testes. These start pumping out testosterone and by the time a baby boy is born, the “default” female brain has become masculine. 2. We now know that’s_.n..o.Lquitahow__iLw.orks. It turns out there are “pro-female” as well as “pro-male” genes, and that sexual differentiation is governed by a delicate balance between the two. In 2006, for example, Pietro Parma at the University of Pavia in Italy, and colleagues, reported that a gene called r-spondin1 promotes the development of the ovaries, and that without it individuals who are genetically female grow up physically and psychologically male, although they have ambiguous external genitalia and are sterile (Nature Genetics, vol 38, p1304).
3. Biologists have also revised their views on the role of sex hormones. Testosterone in men and oestrogen in women were always thought to account for most of the biological differences between the sexes. Testosterone in men and oestrogen in women were always thought to account for most of the biological differences between the sexes. While that remains the mainstream view, it is now clear that the effects of hormones and genes can interact, with implications for the wiring of the brain and, ultimately, for behaviour. Moreover, the contribution of genes can in turn be modified by experience: a child’s early environment can induce chemical modifications of DNA-so-called epigenetic changes-that without altering the actual sequence of a gene changes whether it is active or quiescent in a particular tissue. 4. The identification of all these sex-determining factors and their complex interactions has an important corollary, which is that sex determination is not over by birth, as was once thought. Both nature and nurture play a role in shaping the differences between men and women, nowhere more so than in the brain, which is constantly remoulded throughout our lives.
Many now believe that there are critical periods when the sex of a child’s brain-and everything that accompanies it, including such things as the J!19ivt<:Jua.l’s attit~,Jdes to~ love_ocfoo_d: is particularl(,[Il_alleable.j By the time we reach adulthood there are numerous differences in structure between the brains of men and women, as revealed by brain -imaging studies. These could explain why males and females show such different vulnerabilities to mental illness and learning difficulties, but as yet neuros_c;Jentists know little about how the structural differences translated into behaviour.
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