1. Animal Growth and Development

2. What is the Different between Growth and Development??

3. Animal Development Introduction to animal development
Development requires both cell growth and cell differentiation (different cells express different genes)
How are new organisms produced?

4. Fertilization
In mammals, sperm travel from the vagina to the fallopian tube
Fertilization takes place in the fallopian tube to form Zygote

5. Once fertilization ends…
What’s next? 5

6. How many step happen in animal growth and development?

7. TWO PHASES
Embryonic Phase
Pasca Embryonic Phase

8. Egg and Zygote Polarity
Most animals have eggs and zygote with polarity:
Animal pole: low concentration of yolk.
Vegetal pole: yolk concentrated here 8

9. Morulation Blastulation Gastrulation Differentiation/ Organogenesis
EMBRYONIC PHASE After fertilization…there are 3 major steps of embryonic phase:
Morulation
Blastulation
Gastrulation
Differentiation/ Organogenesis

10. Animal Embryonic Development
Stages of development
1. Early Cleavage (Morulation)
Cleavage begins within an hour of fertilization; series of mitotic divisions
Zygote divides into 2, 4, 8, … smaller and smaller blastomeres without increasing size of embryo
Cleavage involves about 12 divisions resulting in solid ball of blastomeres
How are new organisms produced?

12. In Amphibians Completed in 24 hrs.
1st and 2nd plane is meriodional; 3rd is equatorial
16-64 cell stage – morula
128 – 15,000 cell stage – blastula

13. 2. Cleavage - blastulation
rapid cell divisions
little cell growth
packaging of cytoplasmic heterogeneity
final product is a hollow ball of cells = blastula
cells = blastomeres
hollow cavity = blastocoel 13

14. Cont… yolky eggs alter pattern of divisions
animal hemisphere divides normally
vegetal (yolky) hemisphere
divides less often
produces larger cells
amount of yolk affects cleavage pattern

15. 3. Gastrulation
Gastrulation - sorts all the cells into distinct cell layers (ectoderm, endoderm, and mesoderm)
Blastula (hollow ball of cells) transformed into the Gastrula (three layered stage)

16. Gastrulation 1. Gastrulation begins- Blastopore formed
Blastopore - midway opening on one side of the blastula
-Site of cell migration
from the surface into the interior (Invagination)
- Future site of anus

17. Gastrulation 2. Cell migrating to form layers Archenteron –
primitive gut formed (endoderm)
future mouth

18. Gastrulation 3.Gastrulation complete - Gastrula formed
Endoderm and archenteron -replace the blastocoel
Mesoderm - forms a layer between the ectoderm and endoderm
Ectoderm- forms the outer layer.
Yolk plug- (endoderm) marks the site of the blastopore and of the future anus

19. Gastrulation in a sea urchin embryo
Digestive tube (endoderm)
Key
Future ectoderm
Future mesoderm
Future endoderm
Blastocoel
Mesenchyme cells
Vegetal plate
Animal pole
Vegetal pole
Filopodia pulling archenteron tip
Archenteron
Blastopore
50 µm
Mouth
Ectoderm
Mesenchyme: (mesoderm forms future skeleton)
Anus (from blastopore)
The blastula consists of a single layer of ciliated cells surrounding the
blastocoel. Gastrulation begins with the migration of mesenchyme cells
from the vegetal pole into the blastocoel.
The vegetal plate invaginates (buckles inward). Mesenchyme cells
migrate throughout the blastocoel.
Endoderm cells form the archenteron (future digestive tube). New
mesenchyme cells at the tip of the tube begin to send out thin
extensions (filopodia) toward the ectoderm cells of the blastocoel
wall
Contraction of these filopodia then drags the archenteron across
the blastocoel.
Fusion of the archenteron with the blastocoel wall completes
formation of the digestive tube with a mouth and an anus. The
gastrula has three germ layers and is covered with cilia, which
function in swimming and feeding. 5 1 2 3 4 19

20. WATCH THIS VIDEO ….

21. Differentiation/Organogenesis
Changing process of structure and function become specific tissue.
Formation of organ systems from germ layers 21

22. Ectoderm Makes up the outer covering of the gastrula Becomes:
Nervous system
Epidermis

23. Mesoderm Becomes: Muscles Heart Kidney Dermis
Circulatory, urinary, reproductive system

24. Endoderm
Becomes:
Digestive system
Respiratory System
Liver
Pancreas

25. There are two divisions
Pasca Embryonic Phase
Maturity and Completing become more perfect organism.
There are two divisions
Regeneration
Metamorphosis

26. 1. Regeneration Repairing damage/lost organ. Eg. High Animal
Asexual Reproduction.
Eg. Planaria

27. 2. METAMORPHOSIS 1. Insect a. Ametabole NO metamorphosis
- No Larva Stage
- Increasing body size.
Eg. Book Lice

28. b. Hemimetabola Unperfect Metamorphosis. Stage:
Egg  Larvae  semi-imago  imago/adult.
Eg. Grasshopper
Cockroach

29. c. Holometabola Perfect Metamorphose Stage:
Egg  Larvae (Instar) Pupae  Imago/Adult.
Eg. Butterfly

30. 2. Amphibi Premetamoprhosis Fertelized egg  Kecebong Prometamorphosis
Hind Limb appear and grow slowly.
Climax Metamorposis
Front Limb appear and tail be lost

31. Test yourself... 31