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?
Similarly, in humans, there are 92 chromosomes present and 92 chromatids during anaphase. These numbers remain the same during telophase. It is only after the end of mitosis â when the dividing cells have fully separated and the membranes have reformed â that the normal chromosome number is restored to the cell.