Fetal Development and Epigenetics

In relation to Big Idea 3, which is “Living systems store, retrieve, transmit, and respond to information essential to life processes”, Dr. Moalem writes about epigenetics with fetal development from pages 162-165 and how the first few days after conception can have a huge impact on the growth of the fetus after once it’s born. Dr. Moalem uses the example of childhood obesity being a result of bad nutrition of the mother which are epigenetic signals for the fetus. Explain how bad nutrition in pregnant mothers today lead to children becoming obese. Define the term “epigenetic” and “phenotype” in your answer. Afterwards, research another medical condition that could be a result of epigenetics in fetal development and explain how that works.

(Jenny S. Li - jesli4@students.d125.org)

Capsaicin's effects on different animals

On pages 82-83, Dr. Moalem describes how raw habanero peppers have a burning chemical called capsaicin. This relates to Big Idea 1, the process of evolution drives the diversity and unity of life, because this capsaicin has evolved to affect mammals but not birds.

Capsaicin is characterized as a sticky poison. Describe what this means, how it affects mammals, the best way to ease and prevent these effects in mammals, and how it affects birds.  Also, explain why affecting birds and mammals differently is a selective advantage for the habanero peppers. Besides the burning sensation, what other effects can capsaicin can have on mammals’ bodies in large quantities?

Metabolism

On pages 68- 70 Dr. Maolem talks about a gene in the human body, CYP2D6 and how it can have a major impact on the body. This relates to Big Idea #2, which states: Biological systems utilize free energy and molecular building blocks to grow, reproduce, and to maintain dynamic homeostasis; CYP2D6 is an important gene affecting how the body metabolizes more than 25% of all pharmaceuticals. People who only have very few copies of this gene are considered ‘slow metabolizers’.

Explain in detail what the CYP2D6 gene is and does. Why are too many copies of this gene harmful to the body? What are the advantages and disadvantages for having more or less copies of this gene? Which chromosome is the gene located on? Is this a genetic disorder? If so, explain what type of genetic disorder is it and how it affects the allele frequency. Finally, explain what relation this gene has to Parkinson’s disease and please cite a source.

Pranathi Merneedi (pmernee4@students.d125.org)

Bacteria in Humans

Streptococcal bacteria - On page 112, Dr. Moalem describes streptococcal bacteria which are responsible for a wide range of human diseases. They exhibit a phenomenon called molecular mimicry in order to trick the immune system. The bacteria are able to mimic heart, joint, and even brain cells in humans. This relates to Big Idea 4 (biological systems interact, and these systems and their interactions possess complex properties) since the bacteria's interaction with cells in the body leads to the immune system producing antibodies in an attempt to rid the body of the invaders.

First define what is molecular mimicry, and does it relate to either of the two types of mimicry we had learned in a previous unit (batesian or mullerian mimicry)? Also describe what type of symbiotic relationship the bacteria has with its host. Then pick one of the type of human cells the bacteria can mimic (heart, joint, or brain) and describe two consequences resulting from the attack of the immune system towards this region of the body.

Finally, describe the type of antibodies our immune systems use in order to combat the streptococcal bacteria and how they fight the bacteria.

Faith Teodoro (fteodor4@students.d125.org)

MDS and Methylation

On page 175 Dr. Moalem discussed drugs that were designed to affect methylation patterns, in addition to drugs that cause methylation. To give an example of one such drug, he described azacitidine. This drug is used for the treatment of myelodysplastic syndrome, or MDS.  Explain how azacitidine relates to methylation. Also, MDS is described as a collection of blood disorders, therefore describe the major blood disorders that comprise MDS and explain the symptoms. The relationship between azacitidine and MDS relates to Big Idea 4 (Biological systems interact, and these systems and their interactions possess complex properties) because azacitidine and MDS interact to treat a patient. 

Plants' Defense

On pages 80-83 in the "Hey, Bud, Can You Do Me a Fava?" section (chapter 4) Dr. Sharon Moalem describes how plants use toxins for defense against predators. He also shows how different plant toxins affect humans in parts of the world. Moalem uses examples in history to show the effects some plant toxins can have in humans. This relates to Big Idea 1 (the process of evolution drives the diversity and unity of life) because evolution is the reason that plants have toxins so they can survive and reproduce.

First, find a plant that is consumed by humans and contains a toxin. What are the effects of the toxin? Then, explain why farmers cultivate the Indian vetch (page 80) even if it contains a powerful neurotoxin. Describe how jimsonweed took a part in Bacon's Rebellion (page 81). Why do people accidentally eat jimsonweed every year? Afterwards, explain why people get a burning sensation when they eat certain types of peppers and why water does nothing to help it. If the average human eats somewhere between 5,000 and 10,000 natural toxins every year (page 83), what do you think are the reasons behind this?

(Tyler Hagen-thagen4@students.d125.org)

Infections during Pregnancy

On page 193, Dr. Moalem mentions that "more than half a million mothers die of complications resulting from pregnancy". Among the most common causes of death, including hemorrhage, pregnancy-induced hypertension, and pulmonary embolism, is infection. This relates to Big Idea 3: Living systems store, retrieve, transmit, and respond to information essential to life processes. It is essential for the immune system of  a birthing mother to respond to infections to avoid death.

Please explain why pregnant women and unborn babies are at high risk for some infections and diseases, and identify 2 specific infections prevalent among birthing mothers. Explain the process of fighting these infections, including each barrier of the immune system. Finally, explain how water birthing can prevent aspiration pneumonia in newborn children (page 203).