1. Do Now Download Development Honors Notes off of my website
Where’s my money?!?!?!
Hand in Meiosis Pictures Lab

2. Something to think about as your open up your notes
Humans have approx trillion cells and these cells are all different types (hair, skin, liver, stomach cells, etc.).
How can you explain all these types of cells if humans only start as a single cell?

3. Animal Reproduction & Development

4. Embryology
The study of the
Embryo
An organism in the

5. IMPORTANT! RECOMBINATION
Sperm = DNA (haploid) : one version of each type of chromosome.
Egg = DNA (haploid): same as above
The combination of one sperm with one egg will unite and make .
If another sperm or another egg unite, a human would result.

6. Recombination: SO MANY OPTIONS!

8. 3 stages of embryo development

9. Oogenesis Unequal meiotic divisions unequal distribution of cytoplasm
What is the advantage of this development system?
Oogenesis
Unequal meiotic divisions
unequal distribution of cytoplasm
egg
polar bodies
Meiosis 1 completed
during egg maturation
ovulation
Meiosis 2 completed
triggered by fertilization
Put all your egg in one basket!

10. Fertilization
fertilization
cleavage
Gastrulation
Differentiation

11. Fertilization
Joining of
(nucleus) enters

12. 1) Cleavage Repeated of zygote 1st step to becoming cellular
unequal divisions establishes body plan
different cells receive different portions of egg cytoplasm & therefore different regulatory signals

13. Cleavage zygote  m  b establishes future development blastula zygote
gastrulation
morula
blastula

14. 2) Gastrulation Establish 3 cell layers E M
gastrulation in primitive chordates
2) Gastrulation
Establish 3 cell layers E
outer body tissues
skin, nails, teeth
nerves, eyes, lining of mouth M
middle tissues
blood & lymph, bone & notochord, muscle
excretory & reproductive systems
inner lining
digestive system
lining of respiratory, excretory & reproductive systems
ectoderm
mesoderm
endoderm
protostome vs. deuterostome

15. Testing…
In a study of the development of frogs, groups of cells in the germ layers of several embryos in the early gastrula stage were stained with five different dyes that do not harm living tissue. After organogenesis (organ formation), the location of the dyes was noted, as shown in the table below.
Tissue Stain
Brain Red
Notochord Yellow
Liver Green
Lens of the eye Blue
Lining of the digestive tract Purple

16. Neurulation Formation of notochord & neural tube develop into system
develops into CNS (brain & spinal cord)
Neural tube
Notochord
develops into vertebral column

17. Growth and Differentiation
Umbilical blood vessels
Mammalian embryo
Chorion
Bird embryo
Amnion
Yolk
sac
Allantois
Fetal blood vessels
Placenta
Maternal blood vessels

20. Testing…
All of the following correctly describe the fate of the embryonic layers of a vertebrate EXCEPT
A. neural tube and epidermis develop from ectoderm
B. linings of digestive organs and lungs develop from endoderm
C. notochord and kidneys develop from endoderm
D. skeletal muscles and heart develop from mesoderm
E. reproductive organs and blood vessels develop from mesoderm

21. A B C D E F

23. 3. Growth and Differentiation
As embryo develops, the # of cells continues to
Differentiation
cells become
Different sections of DNA are , some are turned .
Certain cells act as organizers
These cells influence other cells to become certain cells, tissues

24. STEM CELLS Omnipotent = have the potential to be type of cell.
If mitosis is done, all cells are identical.
FACT: all of your cells contain the (because of mitosis)

25. HOW DO WE GET DIFFERENT CELLS?
Differentiation: some DNA is turned off and only some directions are read, for example:
Skin cells: all DNA directions are turned off, except for how to make skin.

27. Internal Development
Development of the embryo , in the of the body

28. Placental Mammals Placenta - part of the wall of the uterus
Site of !!!!!!!!!!!!!!!!!!!!!!!!
Embryo’s and mother’s circulatory system are touching BUT NOT

29. Umbilical cord
Contains that the embryo will get nourishment and oxygen from the mother’s blood to the

30. Human fetal development
4 weeks
7 weeks

31. Human fetal development
10 weeks

32. Human fetal development
12 weeks
20 weeks

33. Human fetal development
The fetus just spends much of the 2nd & 3rd trimesters just growing
…and doing various flip-turns & kicks inside amniotic fluid
Week 20

34. Human fetal development
24 weeks (6 months; 2nd trimester)
fetus is covered with fine, downy hair called lanugo. Its skin is protected by a waxy material called vernix

35. Human fetal development
30 weeks (7.5 months)
umbilical cord

36. positive feedback
Birth

37. Getting crowded in there!!
32 weeks (8 months)
The fetus sleeps 90-95% of the day & sometimes experiences REM sleep, an indication of dreaming

38. Birth (36 weeks)

39. And you think 9 months of BioH is hard!
The end of the journey!
And you think 9 months of BioH is hard!

40. Nonplacental Mammals mammals Duckbilled platypus Anteaters
Embryo begins to
develop in uterus
Crawls into mother’s pouch
Finishes developing in pouch
Kangaroo, opossum

41. 5) Shell – Calcium carbonate,
1) Albumen – S A A E A Y
2) Allantois –
3) Amnion –
4) Yolk –
5) Shell – Calcium carbonate,

42. August 08’

43. June 08’

44. August 07’