Presentation on theme: "A Closer Look at Conception"— Presentation transcript:
1A Closer Look at Conception The Developing ChildChapter 5 Section 2
2Introduction: The Genetic Package Each of us inherit many personal characteristics from our parents.EX: physical build, skin color, hair color & texture, eye color & shape.Just as personal traits can be passed on, so can medical conditions.
3ChromosomesTiny threadlike particles located in the nucleus of every cell.46 chromosomes = 23 pairs
4Genes Each chromosome contains several genes. Genes- the unit that determine the child's inherited characteristics.Genes makeup chromosomes as beads make up a necklace.For every inherited characteristic, a person receives 2 copies- 1 from mom and 1 from dad.
5GenesIf both inherited genes are the same- then the child will have that characteristic.If they are different- the dominant gene will be expressed.Dominant- stronger gene.Recessive- weaker gene.
6Genes Ex: B= Brown Dominant, b= Blue recessive. Dad (Bb) Mom (Bb) Child 1 Child 2 Child Child 4(BB) (Bb) (Bb) (bb)
7Making A Unique PersonEach sperm & egg cell contains a different combination of genes.These cells combine during the fertilization process and produce a unique individual.
8Determining Sex The sex of a child is determined at conception. Every egg cell contains an X chromosome.Each sperm cell will contain either an X or a Y chromosome.The sex of the child is determined by the chromosome carried by the sperm that fertilizes the egg.XX= baby girlXY= baby boy
9Multiple BirthsIdentical Twins= 1 egg divides in half soon after fertilization. Each half grows and divides. 1 Zygote becomes 2.Fraternal Twins= 2 eggs are released and both becomes fertilized
10Infertility Infertile- inability to conceive a child. There are many causes of infertility in both men and women.Options for Infertile Couples:Adoption- a couple legally takes 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 the uterus. Sperm may be the husband’s or from a donor.
11Infertility Options for Infertile Couples: In Vitro Fertilization- Doctor combines a mature ovum from the woman with sperm from her husband. If the ovum becomes fertilized then the doctor places it in the uterus.Ovum Transfer- Similar to In Vitro, except that the ovum is donated by another woman. It is fertilized in the laboratory and placed in the uterus.Surrogate Mother- A surrogate mother is a substitute woman who becomes pregnant to have a baby for another woman.
12Let’s Review List 3 traits that are inherited. Explain how dominant and recessive genes work.How is the sex of a baby determined?What is the difference between identical twins and fraternal twins?What are some disadvantages of fertility drugs?