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?
16 in a normal cell and 8 in a gamete. An onion has 16 chromosomes.   The color of the chromosomes stained in a onion cell is usually a deep purple. 16. 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 chromosomesâ¦ remains constant.