1. Genetics & Heredity

2. Sex Cells
Female
Ovum or Egg
Male
Sperm

3. Chromosomes
Chromosomes are rod shaped chemical compounds that carry genetic coding.
B. The genetic coding transmits characteristics from the parent to the child.

4. Chromosomes Found in both sperm and ovum
Every cell has 23 pairs of chromosomes, 46 total
Sperm and ovum contain 23 chromosomes each.

5. Genes There are hundreds of genes on each chromosome.
B. They carry individual, specific traits.

6. Genes C. They are the building blocks of chromosomes.
D. They are bead-like structures.

7. Genes
E. They can be dominant (stronger) genes which produce the characteristic in the individual
Blue Eyes

8. Genes
F. They can be recessive (weaker) genes which do not produce the characteristic unless transmitted by both parents.
Red Hair

9. Genetic Information An XY combination will produce a male child.
An XX combination will produce a female child.

10. Genetic Information
C. The father determines the sex of the child.

11. Can you trace a line from one x to the other x?
Genetic Information
Color Blindness
Sex linked defects
Female is carrier but defect appears in male.
Can you trace a line from one x to the other x?

12. MULTIPLE BIRTHS

13. FRATERNAL TWINS Form when two eggs are released at the same time and
each is fertilized. They grow
side by side in the uterus.
Because they are the result of
two different ovum and
sperm they are no more alike
in terms of heredity than
other siblings. They may be
of opposite sexes.

14. IDENTICAL TWINS A fertilized egg starts growing by
dividing into two cells. These cells
continue to divide. Sometimes,
the cell mass splits in half soon
after fertilization. Each cell mass
grows into a separate embryo.
They are always the same sex, and
have very similar characteristics
because they began as one zygote.

15. TRIPLETS
* Triplets can occur through several combinations. Three separate ovum could be released and fertilized.
* Two ovum could be released, fertilized and then one ovum splits into separate embryo, resulting in a set of identical twins and one fraternal twin.
* One ovum could split into two parts resulting in identical triplets

16. CONJOINED TWINS Conjoined twins result when
a fertilized ovum begins to
split into two parts, but does
not fully complete the
process. The babies are joined
at whatever location does
not complete the splitting
process.

17. THE END!!