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?
In a regular human body cell, there are 46 chromosomes, 23 from each parent. Of these, 2 are sex chromosomes, so named because they determine the sex of the individual. The other 44 (22 in each set) are called autosomes. Any exceptions to the above are instances of aneuploidy. They are relatively rare.