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?
Most people have 46 chromosomes or 23 pairs of chromosomes. People with Down syndrome have an extra number 21 chromosome for a total of 47 chromosomes. This condition is also called âTrisomy 21.â Trisomy comes from the Latin word tri which means three and some which means body and refers to chromosomes.