A medical procedure used to open a blocked artery. Appeal An appeal is the action you can take if you disagree with a coverage or payment decision made by Medicare, your Medicare health plan, or your Medicare Prescription Drug Plan.
A uniflagellar sperm cell that is motile is referred to as a spermatozoon, whereas a non-motile sperm cell is referred to as a spermatium. Sperm cells cannot divide and have a limited life span, but after fusion with egg cells during fertilization, a new organism begins developing, starting as a totipotent zygote. The human sperm cell is haploid, so that its 23 chromosomes can join the 23 chromosomes of the female egg to form a diploid cell. In mammals, sperm develops in the testicles and is released from the penis.
The sperm cell and the egg cell that come together to form the zygote each contain half the normal amount of DNA. There are 46 chromosomes in a typical human cell. The sperm and the egg each contain only 23 - one copy of chromosomes 1 through 22 plus an X or a Y. Egg cells can only contain an X but the sperm can contain an X or a Y. East Haven High School in CT (10th grade student)