Sources of indoor pollution include. 1  Mold and pollen. 2  Tobacco smoke. 3  Household products and pesticides. 4  Gases such as radon and carbon monoxide. 5  Materials used in the building such as asbestos, formaldehyde and lead.
After conception, your baby begins a period of dramatic change known as the embryonic stage. This stage runs from the 5th through the 10th week of the first trimester of pregnancy. During this stage, the baby is called an embryo. Your babyâs penis or vagina is visible at the end of the embryonic period, but it's not yet possible to tell on an ultrasound if your baby is a girl or a boy. 2  Muscles and movement. 3  Muscles develop and the embryo begins to move.
Which is that of the stages of Human Development. So, in terms of human development an embryo is not a fetus, like a fetus is not a baby, like a baby is not a toddler, like a toddler is not a young adult... etc. Basically if you find the definition of Embryo it is: a developing human from conception to 8 weeks.