Embryology & MicrobiologyBy: 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• 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

This is an example of a retrovirus.

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 MosaicAnimal 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• 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-deadly-smallpox-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• Embryo• Zygote• Placenta• Lytic Cycle• Fetus• IVF• Nervous System

• Down• 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&s

p=-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=microbiol

ogy&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&sc=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+bacteria&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=MumaU9eTAdS-sQScuIGQCw&sqi=2&ved=0CAYQ_AUoAQ&biw=1821&bih=868#facrc=_&imgrc=D4YpTTrnYHZ9WM%253A%3BDMySCgWAwOharM%3Bhttp%253A%252F%252Fcdn.singularityhub.com%252Fwp-content%252Fuploads%252F2009%252F09%252Fin-vitro-fertilization-300x197.jpg%3Bhttp%253A%252F%252Fsingularityhub.com%252F2009%252F09%252F07%252Fin-vitro-fertilization-about-to-go-on-sale-360%252F%3B300%3B197