| Activity #10: Crossing Over
Reference: Text page 144 1) When does it occur? 2) Where does it occur? 3) How does it occur? 4) What�s so important about CROSSING OVER? ! Activity #11: Independent Assortment Reference: Text page 145 1) When does it occur? 2) Where does it occur? 3) How does it occur? 4) How many possible combinations are formed from 23 pairs of homologous chromosomes? (2n ) Activity #12: Sperm and Ovum In some animals, there is no difference in structure between the male and female reproductive cells. These are called isogametes (iso = same). In higher animals, however, the gametes differ. The male gamete is called the sperm and the larger female gamete is the egg or ovum. Sperm 1) Please sketch the sperm and label (figure 39.14b on page 659 text) 2) The sperm is divided into 3 parts, what are they? 3) Which part contains the acrosome? 4) Where is the nucleus? 5) Why would sperm cells need mitochondria? 6) Is the sperm a diploid or haploid? Each sperm is around .05mm in length. 3-5 mL of semen is releases at one time containing about 300-500 million sperm. Ovum 1) The ovum is divided into 2 main parts, what are they? 2) What is the function of the yolk? 3) Is the ovum a diploid or haploid? The ovum is probably the largest cell produced by the body with a volume 100,000 times greater than the sperm. |