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?
Or: there are 23 unique types of chromosome in your cells (remember, we are treating the sex chromosomes as the same for simplicity). After replication of the 46 chromosomes, the cell contains 92 chromatids (in 46 pairs). After mitosis two identical cells are created with the same original number of chromosomes, 46. Haploid cells that are generated through meiosis, such as egg and sperm, only have 23 chromosomes, because, remember, meiosis is a reduction division..