Biological Beginnings by https://padlet.com/jackson_david/25avaa4iy4a9 By: David M. Jackson Human Development 504 en-us 2018-04-26 00:54:42 UTC 2025-10-18 15:24:46 UTC hello@padlet.com Conception jackson_david https://padlet.com/jackson_david/25avaa4iy4a9/wish/255475365 * Male sperm fertilizes female egg.
* Zygote is formed.
* 23 chromosomes from the mother and 23 from the father.
* 46 chromosomes carry heredity from both parents.
* 23rd chromosome determines sex. Females are XX and males are Xy.
* After conception, chromosomes divide, duplicating themselves.
* Mitosis begins creating new cells exactly like the zygote. 
* Each cell has a duplicate of the original 46 chromosomes.
* 2 weeks later zygote attaches itself to the uterus wall.  
* zygote is now considered an embryo.]]> 2018-04-26 00:57:40 UTC https://padlet.com/jackson_david/25avaa4iy4a9/wish/255475365 Prenatal Development jackson_david https://padlet.com/jackson_david/25avaa4iy4a9/wish/255477761 * There's a 9 month gestational period.
* First 2 weeks, zygote goes from fertilization to implantation.
* Weeks 3-8, embryo's organs and body structures are forming.
* Weeks 9 to birth are the period of the fetus.
Reproductive system forms, brain and nervous systems develop and there is gains in weight.  
* For normal prenatal development to occur, proper nutrients from the environment and the genome must code correctly in the proper time frame.
* The genes and the environment play an equal role in the typical development of a fetus.]]> 2018-04-26 01:13:37 UTC https://padlet.com/jackson_david/25avaa4iy4a9/wish/255477761 Birth jackson_david https://padlet.com/jackson_david/25avaa4iy4a9/wish/255479065 STAGE 1: 
* Lasts 12-24 hours
* Contractions are 15-20 minutes a part
* Contractions last up to 1 minute
* Stretching of cervix begins
* Cervix begins to open
* Contractions are 2-5 minutes near end of stage.
* Cervix is dilated to 4 inches.
STAGE 2: 
* The head of the baby moves through the cervix and birth canal.
* Contractions every minute, lasting a minute.
* Stage ends with the birth of the baby.
STAGE 3:
* After birth is when the placenta, umbilical cord and membrane are expelled.
* Last several minutes.]]> 2018-04-26 01:22:17 UTC https://padlet.com/jackson_david/25avaa4iy4a9/wish/255479065 Resource: jackson_david https://padlet.com/jackson_david/25avaa4iy4a9/wish/255480145 Broderick, P. C., & Blewitt, P. (2015). The Life Span: Human Development For Helping Professionals. Boston: Pearson.]]> 2018-04-26 01:29:48 UTC https://padlet.com/jackson_david/25avaa4iy4a9/wish/255480145