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?
Now, note that after the final meiotic split (which produced 4 cells in total), each of the final gametocytes has 23 individual chromosomes. 22 of those chromosomes are the halves of the autosomal chromosome pairs, and one of the chromosomes is either an X or a Y chromosome.