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).

HERV, Psoriasis, Healthy Placenta, HIV

On pages 149-150, Dr. Moalem discuses the importance of retroviruses and viruses in the evolution of human beings. This relates to Big Idea 1 (The process of evolution drives the diversity and unity of life) because in humans, it is found that 8% of the human genome is composed of retroviruses, or elements related to it that have found a permanent place in our DNA. Specifically, it is noted that a healthy placenta is a benefit from HERV and the skin disorder psoriasis is not.


Describe how the virus is able to be a part of the human DNA (offspring's DNA). Define and explain what a Weismann barrier is and how it relates to viruses/ retroviruses? How does a virus/retroviruses cross this barrier. Explain how the Weismann barrier keeps out certain viruses/retroviruses.  Explain how the benefit of a healthy placenta is created. Explain how a hurtful effect of HERV, like psoriasis is created. Connect this with HIV. Compare and contrast the processes, effects, functions between HIV and HERV. Is HIV a type of HERV.


Crystal Chang (cchang3@students.d125.org)

First discovery of vaccines

On pages 125-126, Dr. Moalem described the first discovery of a vaccine by Dr. Jenner after he noticed that milkmaids with cowpox were more resistant to the deadly disease, smallpox, compared to other people within the same community. This relates to Big Idea 3: Living systems store, retrieve, transmit, and respond to information essential to life processes.

From the information from this experiment, explain what vaccination is in your own words. Determine why Dr. Jenner used a scrape of a cowpox sore for infecting the teenage boys compared to any other body fluid such as saliva. What happened when the boys were injected with the cowpox sore in terms of the ability of the smallpox to affect the boys. Be sure to use words such as antigen, antibodies, and memory cells. Describe how genes change in order to produce new antibodies for a new infection. Find another vaccine which is produced by infecting someone with a mild disease whose virus is similar to a deadly disease.

Prince Morkeh (pmorkeh4@student.d125.org)

Aging and Cancer cells vs. Stem cells

On pgs 183-189, Dr. Moalem explains how humans have genetic controls for aging. Cells have evolved to reproduce under a limit. Cells start to die off after reaching this limit and aging starts to take its toll. Cancer, on the other hand, involves cells that avoid this reproducing limit and become immortal cells. This relates to Big Idea 1: The process of evolution drives the diversity and unity of life.

The Hayflick limit is an example of an aging mechanism used by cells.

Using pgs 183-189, define the Hayflick limit explain how normal cells have evolved in relation to aging. Cancer cells on the other hand, are able seemingly able to reproduce infinitely with the use of telomerase. Using information from earlier units and pgs 183-189, explain how telomerase helps avoid this evolutionary reproduction limit, and why cancer cells are deadly. Finally, stem cells, like cancer cells, use telomerase to become immortal. Using pgs 188-189 and further research online, explain why stem cells can be beneficial despite the fact that they reproduce outside the Hayflick limit.

Submitted by Weilly Tong (wtong4@students.d125.org)

Antioxidants and Malaria Susceptibility?

On page 71 Dr. Moalem describes G6PD as a "bouncer" that kicks free radicals out of red blood cells. Free radicals are compounds with incomplete valence shells that can destroy red blood cells without G6PD.  Dr. Moalem then mentions G6PD deficiency, or favism, is an evolutionary adaptation to malaria.

Explain the biochemical reaction that requires G6PD to remove free radicals from hemoglobin. NAPDH plays a role in this reaction; where have we seen NADPH before, and how is it behaving differently now? Why might antioxidants, normally associated with good health, increase the severity of malaria in the body of someone with favism?

This question relates to Big Idea #4 (biological systems interact and result in complex properties) because G6PD interacts with free radicals resulting in electron transfer from G6PD to an acceptor, (un)ruptured hemoglobin, and malaria susceptibility.

Aidan Murphy, amurphy4@students.d125.org

Immune System

On pages 144-145, Dr. Moalem discusses the immense diversity of the immune system. His discussion relates to Big Idea #3 (Living systems store, retrieve, transmit, and respond to information essential to life processes), as the millions of different antibodies are created by the immune system in response to the threats that come from viruses and other microbes.

First of all, how is it possible for these millions of unique antibodies to be created when there are only about 25,000 active, coding genes? Explain this process using Dr. Moalem's description of the V(D)J recombination mechanism. How is the V(D)J mechanism similar or different to the mechanism jumping genes use, and what are the overall evolutionary implications of these adaptable mechanisms? V(D)J is not the only process the immune system uses to react to different threats - research another mechanism that the immune system uses to combat threats, and discuss how that mechanism works.

(Posted by Matthew Zhang; mzhang4@students.d125.org)