Introduction: The Genetic Package • Each of us inherits 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. • EX: asthma, diabetes, some cancers, cystic fibrosis
Making A Unique Person • Each sperm & egg cell contains a different combination of genes. • Sperm: Male • Egg: Female • These cells combine during the fertilization process and produce a unique individual.
Chromosomes • Tiny threadlike particles located in the nucleus of every cell. • Chromosomes are what make up our genetic package • 46 chromosomes = 23 pairs
Genes • 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.
Genes • If both inherited genes are the same- then the child will have that characteristic. • If they are different- the dominant gene will be expressed in the child. • Dominant: stronger gene • Recessive: weaker gene
Let’s Understand Genes (eye color) B= Brown Dominant b= Blue recessive Dad (Bb) Mom (Bb) Child 1 Child 2 Child 3 Child 4 (BB) (Bb) (Bb) (bb)
Determining 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 girl • XY= baby boy
Multiple Births • Identical Twins: 1 egg divides in half soon after fertilization. Each half grows and divides. 1 Zygote (the egg and sperm combined) becomes 2. • Fraternal Twins: 2 eggs are released and both become fertilized Fraternal Identical
Infertility • 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.
Infertility • More 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.