Some secondary sex characteristics include the facial hair of the human male, the relatively prominent breasts of the human female, the antlers found only in the male of most species of deer, and the colorful plumage of the males of many species of birds. The Organizational Hypothesis: In an undamaged fin, the longest fin ray is the second fin ray counting in a dorsal to ventral direction, and this was the case with almost no exception in the present study. They were then moved to m 3 tanks at the same site the summer after hatching, and to the Austevoll facility the following autumn. Reproductive development continues in utero, but there is little change in the reproductive system between infancy and puberty.
Their functional significance is not clear at present. Hair grows on face and body. Orangutans in both locations are mostly solitary. The larynx voice box becomes larger as well, resulting in a deeper voice. Thousands of years ago, orangutans once lived throughout much of Southeast Asia, even on the mainland. Enter your email address.
Views Read View source View history. Not all tissues in the reproductive tract are bipotential. In addition, though the timing of these events varies between individuals, the sequence of changes that occur is predictable for male and female adolescents. The most important variable, they conclude, is the ability for one male to dominate an area. The increase in sex steroid hormones leads to maturation of the gonads and other reproductive organs. Without SRY , different genes are expressed, oogonia form, and primordial follicles develop in the primitive ovary. Puberty is the stage in life when a child's body develops into an adult's body.
CC licensed content, Shared previously. There are two primary sex characteristics for both males and females that aid in the development of the reproductive system. Soon after the formation of the testis, the Leydig cells begin to secrete testosterone. Primary sex characteristics are determined by the hormones that develop within an organism. Where are the testes located for most of gestational time? The latter become Wolffian ducts and form the seminal vesicles, epididymis, and ductus deferens in males, but regress in females. This hair may continue to grow thicker until middle or late adolescence.