After the third dose -- given at age 6 months -- your child will be 80% to 85% immune to whooping cough for 3 to 5 years. Everyone -- including adults -- from age 11 up should receive a booster vaccine, called Tdap. It's a combined tetanus, diphtheria, and pertussis booster vaccine.
How many chromosomes are in the nucleus of an onion root cell? There are 8 chromosomes in the nucleus of an onion root cell. The cells are undergoing mitosis, during which the amount of DNA is doubled even as the number of chromosomes â¦ remains constant. How many chromosomes do onions have?
B. Mitotic Index in the Onion Root Tip The mitotic index is defined as the proportion of cells that are in the process of dividing. The onion root tip is an area of active growth and, therefore, one would expect that mitosis is occurring at a rapid rate. What the mitotic index will do is to tell us how active this tissue is. Using a slide of the onion root tip, count 100 cells and indicate which stage of mitosis each of these cells are in. Enter your data in the following table. Table 1, Calculation of Mitotic Index Observer Interphase Prophase Metaphase Anaphase Telophase Total 1 2 3 4 5 6 7 8 9 10 Totals Mitotic index =