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?
Note that the actual magnification of the image will depend on the size of your monitor. The real size of a typical onion root tip cell is about .075mm (75 micrometers). Interphase. The two cells at the left are in interphase. The material inside the nucleus is largely chromatin(C) which consists of the chromosomes stretched out so that individual chromosomes are not visible. The dark structure(I) represents the nucleolus.