6. April, 2016Uncategorized

Diploid – when a body cell has all the DNA of an organism (46 in strands in humans)

Haploid – when a sex cell has only ½ the # of DNA strands of an organism (23 in humans)

gametes – the haploid sex cells – sperm cells and egg cells

meiosis – cell division resulting in 4 haploid daughter cells

Zygote – a diploid cell that is formed when a haploid sperm cell fertilized a haploid egg cell

Human Embryo – human organism arisen from the first mitotic division of a zygote until 8 weeks of age. Human heart begins to beat at 22 days.

Human Fetus – human organism from 9 weeks until birth