True or false? the production of sperm begins at puberty when spermatogonia undergo meiosis i to form primary spermatocytes, which then undergo meiosis ii to form secondary spermatocytes. these secondary spermatocytes go on to form spermatids, which mature into sperm cells.

Using meiosis, the sporophyte produces spores that are .

Speed is the ratio of the distance of an object moves to

Many organizations release indexes used to measure the development of the world's countries. as we learned in this lesson, these indexes measure many factors, from life expectancy to happiness. in your opinion, what are the three most important factors we can use to determine how developed a country might be? explain your answers in a few sentences.