Author Archives

Moosmosis

Passionate about lifelong learning, global health, and education! Check out our team's award-winning youth education site @moosmosis.org

Recognized by United Nations Academic Impact

2022 National Teacher Appreciation Week: Free Stuff and Teacher Discounts

A huge thank you to all the teachers around the world! May 3 is Teacher Appreciation Day, also known as National Teachers Day, and Teacher Appreciation Week lasts from May 2 – May 6. Teachers are invaluable to our communities. They nurture the growth of our students, both young and old, and inspire us to succeed with the gift of learning and education.

Immunology 101: Stages of B-cell Development [Biology, MCAT, USMLE Medicine]

B-Cell Development Stages. stem cell –> early pro-B cell –> late pro-B cell –> large pre-B cell –> [1st checkpoint – selects for functional heavy chains] –> small pre-B cell –> [2nd checkpoint – select for functional light chains] –> Immature B cell (has surface IgM, no surface IgD). Somatic recombination is the process in which different individual gene segments of the H (heavy) chain combine with rearranged gene segments of the L (light) chain. The enzymes responsible for somatic recombination are the recombinase enzymes (RAG-1 and RAG-2) that recognize specific sequences (RSS) or recombination signal sequences. RAG-1 and RAG-2 are only expressed in B or T lymphocytes. These specific sequences recognized by the RAG-1 or RAG-2 enzymes are either a 1) heptamer or 2) nonamer. The heptamer literally contains 7 nucleotides, and the nonamer literally contains 9 nucleotides. There are typically 12 or 23 nucleotides in between the heptamer and nonamer to separate them.

Biology 101: Gel Electrophoresis

In this educational lesson, we learn about the purpose of gel electrophoresis and how gel electrophoresis works. Gel electrophoresis in a method of separating DNA. It can be used to separate the size of DNA, RNA, and protein. You first start with a variety of different fragments of DNA all mixed together. The gel is a porous matrix like a sponge and separates the DNA based on two main things: 1) size and 2) charge. The charge on DNA is what makes it move through the gel. DNA is a negatively charged molecule, so it will move towards a positive charge.

History 101: What Are The 4 Causes of World War 1?

An international conflict during the 1910’s, World War 1, was contributed by not one factor but numerous factors that led to its extensive atrocity. The aggressive rise and continuation of nationalism throughout countries greatly contributed to the start and four-year length of the war. In addition, the heightened race of militarism and its advanced trench warfare also contributed to the massive scale of the war, including the appalling losses of men as well as the elongated duration. Therefore, both the rise of nationalism, the patriotic feelings of countries’ people to fight, and the pursuit of militarism, advancements of armies, weaponry, and warfare style, played key roles in the contribution of the international conflict World War 1.

Digoxin: How does Digoxin treat heart failure? Mechanism of Action and Side Effects [USMLE, Biology, MCAT, Medicine]

Digoxin is a drug that treats heart arrhythmias, left ventricular systolic dysfunction, and heart failure. In this succinct educational lesson, we learn about how digoxin works in treating heart arrhythmias and heart failure, digoxin toxicity and common side effects, and treatment for digoxin toxicity. We also have a mini quiz at the end, so you can test your knowledge on the pharmacology of digoxin.

Immunology: Treatments for Rheumatoid Arthritis – NSAIDs vs DMARDs vs Glucocorticoids [Biology, Medicine, MCAT, USMLE]

Rheumatoid arthritis is an autoimmune disease characterized by chronic inflammation in the joints of hands, feet, knees, etc. In this quick and easy lesson, we explain the standard medical treatment for patients with rheumatoid arthritis at the USMLE immunology level, including DMARDS (synthetics and biologics), NSAIDS, and glucocorticoids.

Central Chemoreceptor vs Peripheral Chemoreceptor in Respiration [Biology, MCAT, USMLE]

There are two types of chemoreceptors that help control and regulate our respiratory rate: 1) central chemoreceptors and 2) peripheral chemoreceptors. Both central chemoreceptors and peripheral chemoreceptors send signals to the main respiratory center in the brain that unconsciously tells our bodies to increase or reduce pulmonary ventilation. In this lesson, we describe the differences and similarities of central chemoreceptors and peripheral chemoreceptors for the pulmonary system.

The Life Cycle of a Retrovirus: HIV

Retroviruses are a class of viruses that not only infect host cells but also integrate their genetic material into the host genome, establishing a permanent infection that cannot be cured. The most common retrovirus is the human immunodeficiency virus or HIV, which targets and destroys helper T-cells.

Sleep 101: Brain Activity and Sleep Disorders, Sleep Apnea, Circadium Rhythms, and How to Sleep Better at Night

Sleep and Brain Activity Sleep disorders affect up to 70 million people and cost around $15.9 billion annually. EEG stands for electroencephalography, which was used to examine human brain waves in the 1950s. Sleep Disorders: Insomnia, OSA, Apnea, Narcolepsy. Regulation of Sleep. Sleep-Wakefulness Cycle: Circadium Rhythm and Homeostatic System. Tips to sleep better at night.

Primary Essential Hypertension vs Secondary Hypertension: Causes and Health Effects of High Blood Pressure [Biology, MCAT, USMLE]

In this quick, easy-to-understand lesson, we learn about secondary hypertension for USMLE and medicine. Secondary hypertension is defined as high blood pressure (>140/90 or >130/80) caused by an underlying disease, medical condition, or drugs. While primary essential hypertension comprises of the majority of hypertension cases (90%), only 10% of patient cases is secondary hypertension.

Direct Hernia vs Indirect Hernia

Direct vs Indirect Hernia: What is the difference between direct and indirect inguinal hernias? In this easy-to-understand lesson, we explore the differences between direct inguinal hernias and indirect inguinal hernias. Overall, an inguinal hernia is a medical condition, where protrusion or bulge of abdominal contents into the groin area and/or inguinal canal. There are two types of inguinal hernias: 1) direct inguinal hernia and 2) indirect inguinal hernia.

Embryogenesis: Definition, Stages, and Development [MCAT]

Sonic Hedgehog Gene. CNS development and Limb development. In embryology and developmental biology, embryogenesis is the development of an animal or plant embryo, starting with fertilization of an egg cell by a sperm cell. After fertilization, the ovum becomes a diploid zygote. orms forebrain, separates right and left brain, and establishes midline. f there’s a mutation, then we have a whole brain with no separation of right and left, which is bad. This is called holoprosencephaly. Left and right hemispheres fail to separate. There are also facial abnormalities, cleft lip/palate and even severe cyclopia (single eye like a cyclops).

Psychology 101 and the Brain: Stress – Definition, Symptoms, and Health Effects of the Fight-or-Flight Response

The “fight or flight” response is in response to impending danger. For example, the stress responses kicks in when seeing a snake slithering towards you or running away from a bear in the woods. Homeostasis is the normal equilibrium of body function, so stress can be induced by belief that homeostasis might be interrupted. In this guide, we share the effects of stress on the human body system, psychology, immune system, and long-term health effects of chronic stress.

2021 AP English Exam – Literature 101: Literary and Poetry Terms Vocabulary Study Guide – 125 Most Common Literary Terms and Definitions

In this guide, we share 125 most common literary and poetry terms along with their definitions based on the greatest works of Literature and Poems in preparation for the AP English Exam. From dynamic characters and tragedy to comedy and alliteration, we explore the wide range of terminology and their definitions studied in high schools, colleges, and universities.

Biology 101: Microfilaments vs Microtubules in Cell Biology

Microfilaments and microtubules are both important elements of the cytoskeleton, maintaining the structure and integrity of the cell, but there are several differences between microfilaments and microtubules. In this article, we share this information on microfilaments versus microtubules.

Microfilament and Microtubulues are made from different individual subunits. Microfilaments are made from ACTIN, while microtubules are made from TUBULIN.

Cardiology 101 – Atrial Fibrillation (USMLE) : Causes, Symptoms, Diagnosis, and Treatments

In this quick easy-to-understand lesson, we learn about atrial fibrillation, causes, symptoms, diagnoses, and treatments for USMLE medicine. Atrial fibrillation is the most common type of cardiac arrhythmia. This means the heart beat has an irregularly irregular rhythm. Symptoms can include fatigue, dyspnea (difficulty breathing), and heart palpitations in the chest. You diagnose atrial fibrillation via EKG. It can be treated with medications or surgically.

Immunology 101: Innate Immunity vs. Adaptive Immunity

Innate vs Adaptive Immunity: What are the differences between innate and adaptive immunity? The human body has two protective immunological systems against pathogens: the innate immunity and the adaptive immunity. In this quick and easy lesson, we will explain the differences between the innate and adaptive immunity. The innate immunity and adaptive immunity differ based on the type of components that are used to protect the human body. For example, the innate immunity consists of neutrophils, dendritic cells, natural killer cells, macrophages, complements, physical barriers. On the other hand, the adaptive immunity contains components such as T cells, B cells, and antibodies to protect us from viruses, bacteria, and other pathogens.

Infant Developmental Milestones: High-Yield USMLE Points

When does a baby say its first words, Mama and Dada? When does a baby learn to stand up and walk on its own? Is it normal for an infant to develop stranger anxiety at 9 months? In this quick and easy-to-understand lesson, we review the infant developmental milestones at 1 month, 6 months, 9 months, 12 months, 2 years, 3 years, and 4 years. This lesson includes high-yield USMLE quick take-home points, high yield summaries, and practice test questions/answers on infant developmental milestones.