1. A Closer Look at Conception
Chapter 3 Section 2

2. The Genetic Package Nature– Genetics/ Heredity Physical build
Skin color
Hair texture/color
Color/shape of eyes
Shape/size of ears, hands, and feet
Blood type

3. Moment of Conception _____ chromosomes Each contains genes
23 from ______ (father)
23 from mother (_____)
Each contains genes
Determine characteristics
____ genes for each characteristic
One from mom, one from dad

4. Dominant Vs. Recessive
When both genes ________, the child will receive that trait
Ex: both parents pass the blue-eyed trait, child will have blue eyes
When different, the _________ trait will win
Ex: brown-eyed trait (D) vs blue-eyed trait (R): the child will have _______ eyes

5. Gene Pool How are the genes picked? Create an _________ individual
Matter of _________
Create an _________ individual
Siblings will look similar but ________________ __________________

6. How Does it Work??? What does this mean? 1 in 4 chance of blue eyes
BB: 2 dominant= brown
Bb: brown
bb: Blue eye
1 in 4 chance of blue eyes

7. Sex Determination Gender is determined by 2 chromosomes
____________
The _____ contains ___
Sperm – __________
During fertilization
XX= ______________
XY= ______________

8. Multiple Births Beginning of _____________the cell divides into 2
Continue until they divide into millions
Sometimes the growing mass divides into 2
Grow into separate ______________
Produces _____________ twins

9. Identical Twins Dividing mass of cells Form 2 embryos Same ______
Very similar characteristics
Due to the same _______ and same _________
If the split is not complete- ___________ twins occurs

10. Fraternal Twins
Results when 2 eggs are released at the _________________
Each fertilized by different _________
Not always the same sex
No more alike than ordinary ___________

11. Multiple Births In more than 2 births: Example: triplets
Can be identical, fraternal, or both
Example: triplets
One ovum could divide into 3 parts (_________)
2 eggs are fertilized and one splits (2 identical & one fraternal)
______ eggs released at once (_____________)

12. Genetic Worksheet