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?
If it is a human zygote with no mutations, then it will contain 46 chromosomes. Each parent gives the zygote 23 chromosomes. All human gametes without mutations contain 23 and when joined during fertilization they form a zygote with 46 chromosomes. However, chromosome number varies by species, for example a normal pigeon zygote would have 80 chromosomes.