1. Antonie van Leeuwenhoek
Developed microscopes for observing living organisms
1674 discovered protists
1677 discovered spermatozoa
1682 discovered striated muscle fibers

2. http://www. molecularexpressions

3. Schematic Human Sperm Cell
Homunculus

4. Human (Homo sapiens) Sperm Photograph

5. Mammalian Syngamy: Plasmogamy

6. Calcium release spreading across an egg cell during syngamy

7. Amphioxus (lancelet) adult, zygote, and early cleavage
not to scale!

8. Amphioxus (lancelet) cleavage

9. Amphioxus (lancelet) gastrulation and adult
not to scale!

10. Morphogenetic movements of cells during development

11. Amphioxus (lancelet) nerulation

12. Primary Tissue Layer Tissue or Organ Ectoderm Mesoderm Endoderm
Origin of some mammalian tissues or organs
Primary Tissue Layer
Ectoderm
Mesoderm
Endoderm
Epidermis
Muscle
Lungs
Hair
Bone
Liver
Nails
Blood
Pancreas
Eye lens
Notochord
Digestive lining
Nerve system
Kidneys
Bladder
Nasal oral mucosae
Gonads
Tissue or Organ

13. Frog (Rana pipiens) embryology

14. Frog (Rana pipiens) zygote

15. Frog (Rana pipiens) embryo: early cleavage

16. Frog (Rana pipiens) embryo: later cleavage

17. Chicken (Gallus gallus) zygote and early cleavage
blastodisc
yolk

18. Chicken (Gallus gallus) gastrulation

19. Chicken (Gallus gallus) embryo after 4 days of incubation

20. Human (Homo sapiens) embryo

21. Human (Homo sapiens) embryo

22. Human (Homo sapiens) embryo

23. Human (Homo sapiens) embryo

24. Comparison of vertebrate embryos of six species at 3 stages
Ontogeny recapitulates Phylogeny

25. Typical sigmoid (S-shaped) growth curve: logistic curve
plateau phase
log phase
Weight
lag phase
Age

26. Weight growth in a mouse (Mus musculus)
Puberty 16 14 12 10 8 6 4 2
Weight in grams
Weaning
Days after birth

27. Weight growth in an insect (Malanoplus) with 5 molts
adult
150
100 50
Sudden increase when body lacks exoskeleton
(soft shell crab)
Weight (mg) 5
Nymphal instars:
feeding 3 4 2 1
zygote
Age in days
How does weight increase suddenly when not feeding?

28. Does growth continue indefinitely?
Differential growth in weight of the Homo sapiens body and its parts 20 15 10 5
Body
Does growth continue indefinitely?
Why does the curve inflect here?
Heart
Multiples of weight at birth
Brain
Age in years

29. Average decline in a Homo sapiens from age 30 to 75 years
Characteristic
Percent Decline
Weight of brain 44
Number of nerve cells in spinal cord 37
Velocity of nerve impulse 10
Number of taste buds 64
Blood supply to brain 20
Output of heart at rest 30
Speed of return to normal pH of blood after displacement 83
Number of filtering subunits in kidney
Filtration rate of kidney 31
Capacity of lungs
Maximum O2 uptake during exercise 60

30. Three larval stages and a sea star adult (Asterias vulgaris) gastrula
gastrula
benthic adult
planktonic larvae
bipinnaria
brachiolaria

31. Monarch butterfly complete metamorphosis: zygote (“egg”)
Danaus plexippus

32. Monarch butterfly complete metamorphosis: larva
Danaus plexippus

33. Monarch butterfly complete metamorphosis: larva
Danaus plexippus

34. Monarch butterfly complete metamorphosis: larva
Danaus plexippus

35. Monarch butterfly complete metamorphosis: pupa
Danaus plexippus

36. Monarch butterfly complete metamorphosis: adult
Danaus plexippus

37. Monarch butterfly complete metamorphosis: adult
Danaus plexippus

38. Incomplete (gradual) metamorphosis in grasshoppers
zygote
Incomplete (gradual) metamorphosis in grasshoppers
Brachystola magna

39. Relative DNA repair rate among mammals
100
(Homo sapiens) Human
(Loxodonta africana) Elephant
(Bos taurus) Cattle
Life span in years (log scale) 10
Hamster (Mesocricetus auratus)
Rat (Rattus norvegicus)
Mouse (Mus musculus) 1
Shrew (Suncus murinus)
Relative rate of DNA repair