1. Chapter 4 Section 1
The Developing Baby

2. Conception
Ovulation - About every 28 days, an ovum (egg cell) is released by one of a woman’s two ovaries.
Menstruation Cycle
When ovum is released from ovary, it moves through the fallopian tube into the uterus.
Takes about 2-3 days
When it reaches the uterus, it usually breaks up and leaves the body with the menstrual flow.
When a sperm reaches the fallopian tube, it may penetrate and fertilize the ovum.

4. Conception Conception – the sperm fertilizing the ovum
The ovum usually lives 12 to 24 hours
The sperm can lives 48 to 72 hours
During a normal menstrual cycle, there are 3-4 days in which intercourse can lead to conception.

5. Ectopic Pregnancy
Occurs when the baby begins to grow somewhere other than in the uterus, such as the fallopian tubes.
Dangerous for the mother
Do not end in a live birth

6. Genetics
At the moment of conception, every human baby receives 46 chromosomes
Chromosomes come in pairs you get 23 pairs total
Half from mother, half from father
Per pair: 1 chromosome from father’s sperm, 1 chromosomes from mother’s egg = 2 chromosomes = 1 pair
Each chromosomes has hundreds of thousands of genes
No two people, besides identical twins, have identical DNA.

7. Dominant and Recessive Genes
For each inherited characteristic, a person receives two copies of a gene
One from mother, one from father
When both are the same, the child gets that gene automatically
Dominant gene – a stronger gene
Controls the characteristic
Recessive gene – a weaker gene
Not expressed

8. Making a Unique Person Gender determined at conception
X chromosomes = female chromosome
Y chromosomes = male chromosome
Every woman has 2 X chromosomes
Every male has 1 X and 1 Y chromosomes
At conception, the woman automatically gives X, so father determines sex (based on if he gives X or Y chromosome)
XY = Male
XX = Female

9. Multiple Births
Number of children determined at conception or soon after
Most common = twins

10. Twins 3 in 100 births are twins Identical Fraternal
One egg and one sperm divide into two cells
4 in 1,000 births are identical twins
Fraternal
Two eggs released into uterus at one time, get fertilized by two different sperm
May not look alike
23 in 1,000 births are fraternal twins

11. Three or more births
Very rare, but more likely if using treatments to help women get pregnant.

12. Infertility Infertility – the inability to conceive a child
40% linked to women
40% linked to men
20% unknown causes, or linked to both partners

13. Options for Infertility
Adoption – A couple is legally taking on all responsibilities and rights for raising, loving, and caring for a child in need of a permanent home.
Artificial Insemination – Doctor injects sperm into a woman’s uterus. Procedure timed to take place when a woman’s ovary releases an ovum.
Sperm is often from the woman’s husband
Sperm donor can be used

14. Options for Infertility
In Vitro Fertilization – Process used to treat many causes of infertility, such as when a woman has damaged fallopian tubes. Under microscope, the doctor combines a mature ovum from the woman with sperm from her husband and places it in the woman’s uterus. Pregnancy occurs if the fertilized egg attaches itself to the uterus
Ovum Transfer – This procedure is similar to in vitro fertilization, except an ovum has been DONATED by another woman. Then fertilized in lab, and put inside of the woman.

15. Options for Infertility
Surrogate Mother – A woman who becomes pregnant to have a baby for another woman. This option requires legal arrangements be made for everyone involved, including the child.
THINK: Baby Mama!
All options are very expensive and often medical insurance does not cover the costs, or covers very little of the costs.

16. Three Stages of Pregnancy
Germinal Stage – fertilization of the egg
Embryonic Stage – development in 3rd – 8th week of pregnancy
Fetal Stage – From 8th/9th week until birth

17. Germinal Stage Cell Division Implantation
Zygote begins to grow by cell division while in fallopian tubes
One cell multiplies until there are hundreds of cells
Takes about 4 days to reach the opening of the uterus
Implantation
Zygote attaches itself to the side of uterus and continues to grow
Only the size of a pin head

18. Embryonic Stage
Amniotic Sac forms – Liquid that forms and protects the baby
Placenta develops – Tissue that connects the developing baby to the uterus
Formed from special layers in the uterus
Rich in blood vessels that allow food and oxygen to flow to the baby
Umbilical cord develops – long tube that connects the baby to the placenta
Takes carbon dioxide and other waste products away from the baby

19. Fetal Stage Vocal Cords Develop
Digestive system and kidneys begin to function
Spontaneous moves are possible by the end of the third month.
Development is completing
Fetuses are very active in the fetal stage
Grows to full term
Ready for birth