Antonie van Leeuwenhoek 1632-1723

Developed microscopes for observing living organisms

1674 discovered protists

1677 discovered spermatozoa

1682 discovered striated muscle fibers

http://www.molecularexpressions.com/primer/images/introduction/leeuwenhoek.jpg

http://students.ou.edu/J/Renee.E.Jones-1/Van%20leeuwenhoek%20Scope.jpg

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http://cell.sio2.be/introduction/images/microleeuw.jpg

Schematic Human Sperm Cell

http://academic.evergreen.edu/v/vivianoc/homunculus.gif

Homunculus

Human (Homo sapiens) Sperm Photograph

Mammalian Syngamy: Plasmogamy

Calcium release spreading across an egg cell during syngamy

Amphioxus (lancelet) adult, zygote, and early cleavage

not to scale!

Amphioxus (lancelet) cleavage

Amphioxus (lancelet) gastrulation and adult

not to scale!

Morphogenetic movements of cells during development

Amphioxus (lancelet) nerulation

Origin of some mammalian tissues or organs

Ectoderm Mesoderm EndodermEpidermis Muscle Lungs

Hair Bone Liver

Nails Blood Pancreas

Eye lens NotochordDigestive

lining

Nerve system

Kidneys Bladder

Nasal oral mucosae

Gonads

Primary Tissue LayerT

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Frog (Rana pipiens) embryology

Frog (Rana pipiens) zygote

Frog (Rana pipiens) embryo: early cleavage

Frog (Rana pipiens) embryo: later cleavage

Chicken (Gallus gallus) zygote and early cleavage

yolk

blastodisc

Chicken (Gallus gallus) gastrulation

Chicken (Gallus gallus) embryo after 4 days of incubation

Human (Homo sapiens) embryo

Human (Homo sapiens) embryo

Human (Homo sapiens) embryo

Human (Homo sapiens) embryo

Comparison of vertebrate embryos of six species at 3 stages

Ontogeny recapitulates Phylogeny

Typical sigmoid (S-shaped) growth curve: logistic curve

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Weight growth in a mouse (Mus musculus)

http://www.sasionline.org/antsfiles/articles/images/Dino/mouse.jpg

http://www.c-wilkie.pwp.blueyonder.co.uk/jokes/images/mouse_sex.gif

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Weaning

Puberty

0 20 40 60

Weight growth in an insect (Malanoplus) with 5 molts

adult

zygote

Nymphal instars:

1 23

4

5

Sudden increase when body lacks

exoskeleton(soft shell crab)

feeding

How does weight increase suddenly when not feeding?

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Differential growth in weight of the Homo sapiens body and its parts

Why does the curve inflect here?

Does growth continue indefinitely?

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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 44

Filtration rate of kidney 31

Capacity of lungs 44

Maximum O2 uptake during exercise 60

Three larval stages and a sea star adult (Asterias vulgaris)

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gastrula

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benthic adult

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Monarch butterfly complete metamorphosis: zygote (“egg”)

http://www.monarchwatch.org/update/2003/egg_glue1.jpg

Danaus plexippus

Monarch butterfly complete metamorphosis: larva

Danaus plexippus

Monarch butterfly complete metamorphosis: larva

Danaus plexippus

Monarch butterfly complete metamorphosis: larva

Danaus plexippus

Monarch butterfly complete metamorphosis: pupa

Danaus plexippus

Monarch butterfly complete metamorphosis: adult

Danaus plexippus

Monarch butterfly complete metamorphosis: adult

Danaus plexippus

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Incomplete (gradual)

metamorphosis in grasshoppers

zygote

Brachystola magna

Relative DNA repair rate among mammals

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Relative rate of DNA repair

(Homo sapiens) Human(Loxodonta africana) Elephant

(Bos taurus) Cattle

Hamster (Mesocricetus auratus)

Rat (Rattus norvegicus)

Mouse (Mus musculus)

Shrew (Suncus murinus)