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?
Generally, a cactus has 22 chromosomes arranged as 11 pairs. Such a cactus is called 'diploid', from the Greek 'diploos' and 'eidos' for 'double' and 'form', respectively. In the way of comparison, humans tend to have 46 chromosomes arranged as 23 pairs. But some cactus plants have more than two sets of chromosomes. For example, it's possible for a cactus to have 44 or even 66 chromosomes. Such a cactus is called 'polyploid', from the Greek 'polu' and 'ploos' for 'many' and 'fold', respectively.