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?
The size of the onion bulb is dependent upon the number and size of the green leaves or tops at the time of bulbing. For each leaf, there will be a ring of onion. The larger the leaf, the larger the ring will be when the carbohydrates from the leaves are transferred to the rings of the bulb.