In mammals, sex chromosomes start to program autosomal gene expression and epigenetic patterns very soon after fertilization. Yet whether the resulting sex differences are perpetuated throughout development and how they connect to the sex-specific expression patterns in adult tissues is not known. There is a dearth of information on the timing and continuity of sex biases during development.
Avian chemical communication is a rapidly emerging field, but has been hampered by a critical lack of information on volatile chemicals that communicate ecologically relevant information semiochemicals. A possible, but as yet unexplored, function of olfaction and chemical communication in birds is in parent-embryo and embryo-embryo communication. Communication between parents and developing embryos may act to mediate parental behaviour, while communication between embryos can control the synchronicity of hatching.
See what's happening with your baby in the third month of your pregnancy. Sometime in the last few days, the first detectable brain waves went coursing through your baby's head. What kind of thoughts might she be thinking?
The reproductive system is a collection of internal and external sex organs which work together for the purpose of sexual reproduction. The development of these reproductive organs begins at an early stage in the embryo. There is a close link throughout with the development of the urinary system.
Sexual differentiationin human embryologythe process by which the male and female sexual organs develop from neutral embryonic structures. The normal human fetus of either sex has the potential to develop either male or female organs, depending on genetic and hormonal influences. In humans, each egg contains 23 chromosomesof which 22 are autosomes and 1 is a female sex chromosome the X chromosome.
Sexual differentiation is the process of development of the differences between males and females from an undifferentiated zygote. As male and female individuals develop from zygotes into fetusesinto infants, children, adolescents, and eventually into adults, sex and gender differences at many levels develop: geneschromosomesgonadshormonesanatomyand psyche. Sex differences range greatly and include physiologically differentiating.
NCBI Bookshelf. Sex differences of importance to health and human disease occur throughout the life span, although the specific expression of these differences varies at different stages of life. Some differences originate in events occurring in the intrauterine environment, where developmental processes differentially organize tissues for later activation in the male or female.
Sexual differentiation in humans is the process of development of sex differences in humans. It is defined as the development of phenotypic structures consequent to the action of hormones produced following gonadal determination. The development of sexual differences begins with the XY sex-determination system that is present in humans, and complex mechanisms are responsible for the development of the phenotypic differences between male and female humans from an undifferentiated zygote. At an early stage in embryonic development, both sexes possess equivalent internal structures.
While you might think of child development as something that begins during infancy, the prenatal period is also considered an important part of the developmental process. Prenatal development is a time of remarkable change that helps set the stage for future psychological development. The brain develops over the course of the prenatal period, but it will continue to go through more changes during the early years of childhood.