Upload
danielle-riley
View
214
Download
1
Tags:
Embed Size (px)
Citation preview
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.
Tiny threadlike particles located in the nucleus of every cell.
46 chromosomes = 23 pairs
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.
If 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.
Ex: B= Brown Dominant, b= Blue recessive.
Dad (Bb) Mom (Bb)
Child 1 Child 2 Child 3 Child 4
(BB) (Bb) (Bb) (bb)
Each sperm & egg cell contains a different combination of genes.
These cells combine during the fertilization process and produce a unique individual.
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
Identical 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
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.
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.
1. List 3 traits that are inherited.2. Explain how dominant and
recessive genes work.3. How is the sex of a baby
determined?4. What is the difference between
identical twins and fraternal twins?5. What are some disadvantages of
fertility drugs?
Heredity in the Works Worksheet