1. Development and Differentiation

2. An egg and a sperm cell combine in the process called…
…Fertilization
- results in genetic recombination
Egg cell
(haploid)
Sperm cell
(haploid)
Zygote
(diploid)

4. After fertilization, the zygote divides by mitosis MITOSIS
DIFFERENTIATION
BEGINS
the zygote divides by mitosis

5. After mitosis… The cells begin to take on specific functions.
This process is called differentiation.
leads to the various cell types
Ex. blood cells, kidney cells, and nerve cells

6. As a result Every cell of an organism has the same DNA
But depending on the cell type, some genes are turned on and which are turned off
This is called gene expression

7. Each cell has a full cookbook
Pull out and make one recipe

8. Gene expression can change due to signals from inside and outside the cell
Hormones
Temperature
Chemicals

9. In the alligator snapping turtle (bottom left), more males develop at moderate temperatures than very cool or very warm ones. But temperatures at which maleness is determined varies among species.

11. Human Development Embryonic development occurs in the uterus
After 2 months the major organs have formed and the embryo becomes a fetus

13. The placenta allows for the diffusion of nutrients, oxygen and waste between mother and baby

14. Sonogram

15. This is when the baby is most susceptible to damage.
In the early stages of pregnancy, when the baby’s major organs are not fully developed
This is when the baby is most susceptible to damage.
The following can interfere with the baby's development:
Alcohol
prescription and recreational drugs
Infection
Nutritional deficiencies
X-rays or radiation therapy

17. Reproductive Technology
help some couples to become pregnant
In vitro fertilization (IVF)
Egg donors
Sperm donors
Surrogate