Embryology &
Microbiology
By: Shane Degnan, Nikhil Mehta, Nick Juliano and Ryan
Jeffery
Embryology
• Embryology: The branch of biology that studies the formation
and early development of living organisms.
• Stages
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•
•
•
Zygote
Morula
Blastula
Gastrula
• Processes
• Fertilization
• Implantation
• Gastrulation
This is a developing zygote.
Fertilization
• First, the egg and sperm come together to form a zygote.
• Next, the zygote divides to form the morula. These divisions
are called cleavage.
• Then, a solid ball of cells is formed called a morula.
• After, a fluid filled ball of cells is formed called a blastula.
Implantation
• The blastula attaches to the uterine wall.
• Placenta: Transports nutrients, gas, and waste from mother to
fetus.
• Amniotic sac: Cushions and protects the embryo and keeps it
moist.
• Umbilical cord: Connects the placenta to the fetus.
• Amnion: membrane which forms the amniotic sac
• Chorion: Combines with the uterine lining to form the
placenta
Gastrulation
• The process in which the cell develops 3 germ layers to form a
gastrula.
• Endoderm
• Innermost layer, turns into the digestive tract
• Mesoderm
• Middle layer, turns into the internal organs
• Ectoderm
• Outermost layer, turns into the skin & nervous system
Cell Differentiation
• Once the 3 germ layers are formed, cell differentiation begins.
• Cell differentiation: The process of giving cells specific jobs.
• Neuralation: development of the nervous system
• 1st system to develop, occurs soon after gastrulation
• Organogenesis: organs start to form
• Morphogenesis: limbs start to form
Stem Cells
• Stem Cells: unspecialized cells that have the potential to
differentiate.
• Pluripotent
• Can become any type of cell
• Totipotent
• Form all the cell types in a body, plus the extraembryonic, or
placental, cells
• Multipotent
• Differentiate into cells with specific functions
• Adult Stem Cell
• Replenish damaged tissue, found in both children & adults
The Chicken Embryo Lab
• In this lab, we explored the many processes and stages
involved with the formation of an embryo, which included
fertilization, blastulation and gastrulation.
• In this lab, we observed the similarities of developing
embryos. In these pictures we see a chicken (left) and a turtle
(right) in their developmental stages.
IVF
• In Vitro Fertilization: fertilization occurs in a lab and the zygote
is then transported into the woman's’ body.
• This picture demonstrates how IVF is performed.
Media
• This Ted Ed video will visualize both the internal and external
stages occurring from conception from the perspective of
both the parent and the developing fetus.
• http://www.ted.com/talks/alexander_tsiaras_conception_to_
birth_visualized
Microbiology
Virus
• A nonliving particle that needs a host cell to survive
• Structure
• Contain DNA or RNA
• Surrounded by a protein coat called a CAPSID
• Reproduction
• Lytic Cycle
• Immediately infects and destroys the host cell
• Lysogenic Cycle
• Hides in the host cell until signaled to replicate
• This picture shows DNA and RNA. Viruses may contain one or the
other, but never both.
Prevention
•
•
•
•
Viral infections usually involve several body parts
Antibiotics can NOT kill viruses
Vaccines are used to prevent viruses
Vaccinations: dead or weakened version of the virus that
helps to increase immunity in the host
• Antibody: Immune system’s response to the disease
• Antigen: Proteins attached to an infection
Examples
• Bacteriophage: A virus that attacks bacteria
• Has a protein “tail” that is used to infect the host cell
• Retrovirus
• Uses reverse transcriptase to create opposite DNA of the host
cell. This DNA joins with the original host cell’s DNA so when the
cell divides, the viral DNA is spread.
Retrovirus: HIV (Human Immunodeficiency Virus)
Plant Virus: Tobacco Mosaic
Animal Virus: Ebola
Bacteria
• Prokaryotes, living, unicellular, most numerous organisms on
earth, first form of life, 99% are helpful
• Bacterial infections are normally localized to one point
• Helpful: food production, water purification, digestion, water
purification, environment
• Harmful: spoil foods, cause disease
Oxygen Relationships
• Obligate aerobe: requires oxygen to live
• Obligate anaerobe: requires complete absence of oxygen to
live
• Facultative anaerobe: can either survive with or without
oxygen
Reproduction
• Binary Fission: identical offspring by splitting in half
• Most common form of reproduction
• Conjugation: some bacteria exchange genetic info by forming
a temporary bridge
• Endospore: when conditions are unfavorable, the bacteria
goes dormant by forming an endospore
Shapes
•
•
•
•
•
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Coccus: sphere
Bacillus: rod
Spirillum: spiral
Diplo: pair
Strepto: chain
Straphylo: bunch
• This picture is a visual representation of these shapes.
Media
• http://ed.ted.com/lessons/how-we-conquered-the-deadlysmallpox-virus-simona-zompi
• This is a Ted Ed video demonstrating how vaccinations are
used to prevent the spread of viruses. In this video, the
Smallpox virus is further examined.
Final Review
• Solve!!!
Answer Key
• Across
•
•
•
•
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•
Embryo
Zygote
Placenta
Lytic Cycle
Fetus
IVF
Nervous System
• Down
•
•
•
•
•
•
•
•
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Binary Fission
Antibody
Morphogenesis
Vaccine
Antibiotic
Cleavage
Coccus
Mesoderm
Virus
Images Cited
• http://www.bing.com/images/search?q=zygote&qs=n&form=qbir&pq=zygote&sc=8-5&sp=1&sk=#view=detail&id=EBCC02A326AF7EC2414072B80BDC5E82D076C5F5&selectedIndex=0
• http://www.jillstanek.com/wp/wp-content/uploads/2011/05/chicken-embryo.jpg
• http://www.bing.com/images/search?q=microbiology&qs=n&form=QBIR&pq=microbiology&sc=8
-7&sp=1&sk=#view=detail&id=E216011401C48C4F421298078A9995B6E66F1513&selectedIndex=5
• http://www.bing.com/images/search?q=turtle+embryo&qs=n&form=QBIR&pq=turtle+embryo&s
c=8-11&sp=1&sk=#view=detail&id=1DD00537E2486AAE096C16FC085CD958CE9CF633&selectedIndex=1
• http://www.bing.com/images/search?q=dna+and+rna&qs=n&form=QBIR&pq=dna+and+rna&sc=
8-11&sp=1&sk=#view=detail&id=DBAEC9DDD6BC1A6E86B4BE53040913C9F95DCC25&selectedIndex=1
• http://www.bing.com/images/search?q=shapes+of+bacteria&qs=n&form=QBIR&pq=shapes+of+b
acteria&sc=8-10&sp=1&sk=#view=detail&id=305AD057B39F0A8B341EF039DFB04659881DF071&selectedIndex=5
• http://www.google.com/search?q=in+vitro+fertilization&safe=active&source=lnms&tbm=isch&sa
=X&ei=MumaU9eTAdSsQScuIGQCw&sqi=2&ved=0CAYQ_AUoAQ&biw=1821&bih=868#facrc=_&imgrc=D4YpTTrnYHZ9W
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