Search results
Results from the WOW.Com Content Network
In biological terms, human development entails growth from a one-celled zygote to an adult human being. Fertilization occurs when the sperm cell successfully enters and fuses with an egg cell . [2] The genetic material of the sperm and egg then combine to form a single cell called a zygote and the germinal stage of prenatal development commences.
Scalp hair was reported to grow between 0.6 cm and 3.36 cm per month. The growth rate of scalp hair somewhat depends on age (hair tends to grow more slowly with age), sex, and ethnicity. [ 3 ] Thicker hair (>60 μm) grows generally faster (11.4 mm per month) than thinner (20–30 μm) hair (7.6 mm per month).
When cells on one side of a stem grow longer and faster than cells on the other side, the stem will bend to the side of the slower growing cells as a result. This directional growth can occur via a plant's response to a particular stimulus, such as light ( phototropism ), gravity ( gravitropism ), water, ( hydrotropism ), and physical contact ...
Human embryology is the study of this development during the first eight weeks after fertilization. The normal period of gestation (pregnancy) is about nine months or 36 weeks. The germinal stage refers to the time from fertilization through the development of the early embryo until implantation is completed in the uterus.
Although different animal tissues grow at different rates and produce organs of very different proportions, the overall growth rate of the entire animal body can be modulated by circulating hormones of the Insulin/IGF-1 family, which activate the PI3K/AKT/mTOR pathway in many cells of the body to increase the average rate of both cell growth and cell division, leading to increased cell ...
Complex, multi-joint movements, like a barbell snatch, might take months—or even years—to master. The more joints and muscles involved, the longer it takes for your brain to establish ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Cell growth refers to an increase in the total mass of a cell, including both cytoplasmic, nuclear and organelle volume. [1] Cell growth occurs when the overall rate of cellular biosynthesis (production of biomolecules or anabolism) is greater than the overall rate of cellular degradation (the destruction of biomolecules via the proteasome, lysosome or autophagy, or catabolism).