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Article summarizing cell division with time lapse cell division video of 30hours pro vs eukaryotic division.

This two-minute video provides brief background on the use of zebrafish as a model in studying animal development, before showing a time-lapse sequence of a fertilized zebrafish egg developing into a larva.  The video includes some annotations that help orient the viewer during the time-lapse sequence.  Teachers might want to mute the narration beginning at 0:42 min to avoid giving students too much information.  This phenomenon could stimulate the following driving questions: How does the zebrafish develop from one cell to the many cells that make up the larva? How do the zebrafish cells divide? How are the developing zebrafish cells similar and different from each other? If all cells in the zebrafish develop from the same original cell, then how do some cells develop differently than others? How are cell division and growth related? 

In a paper this week in Science, Vogelstein and Cristian Tomasetti, who joined the biostatistics department at Hopkins in 2013, put forth a mathematical formula to explain the genesis of cancer. Here's how it works: Take the number of cells in an organ, identify what percentage of them are long-lived stem cells, and determine how many times the stem cells divide. With every division, there's a risk of a cancer-causing mutation in a daughter cell. Thus, Tomasetti and Vogelstein reasoned, the tissues that host the greatest number of stem cell divisions are those most vulnerable to cancer. When Tomasetti crunched the numbers and compared them with actual cancer statistics, he concluded that this theory explained two-thirds of all cancers.

groups of cells in the blastula are synchronized to divide at the same time through mitosis. Some of these cells will eventually give rise to the sand dollar's germ cells. Others will play important roles in various developmental processes, such as cell differentiation, the formation of the digestive system, and the development of the exoskeleton. Despite their different characteristics and roles, all of the sand dollar's cells (except for eggs or sperm) are genetically identical due to mitosis.

The cellular life cycle, also called the cell cycle, includes many processes necessary for successful self-replication. Beyond carrying out the tasks of routine metabolism, the cell must duplicate its components - most importantly, its genome - so that it can physically split into two complete daughter cells. The cell must also pass through a series of checkpoints that ensure conditions are favorable for division.

In 1977, a University of Oxford statistician named Richard Peto pointed out a simple yet puzzling biological fact: We humans should have a lot more cancer than mice, but we don't. Dr. Peto's argument was beguilingly simple. Every time a cell divides, there's a small chance it will gain a mutation that speeds its growth. Cells that accumulate several of these mutations may become cancerous. The bigger an animal is, the more cells it has, and the longer an animal lives, the more times its cells divide. We humans undergo about 10,000 times as many cell divisions as mice - and thus should be far more likely to get cancer.

How do cancer cells grow? How does chemotherapy fight cancer (and cause negative side effects)? The answers lie in cell division. George Zaidan explains how rapid cell division is cancer's "strength" -- and also its weakness.

Meiosis, the form of cell division unique to egg and sperm production, sets the stage for sex determination by creating sperm that carry either an X or a Y sex chromosome. But what is it about the X or Y that determines sex? Before a meiotic cell divides, its two sets of chromosomes come together and cross over, or swap, segments. The first animation shows normal crossing over, where the X and Y chromosomes exchange pieces only at their tips. The second animation shows a rare mistake in which the Y chromosome transfers a gene called SRY to the X chromosome, resulting in sex-reversed babies. Studies of sex-reversed individuals led researchers to identify the master switch for sex determination, the SRY gene, which tells a fetus to become a boy.

Meiosis, the form of cell division unique to egg and sperm production, sets the stage for sex determination by creating sperm that carry either an X or a Y sex chromosome. But what is it about the X or Y that determines sex? Before a meiotic cell divides, its two sets of chromosomes come together and cross over, or swap, segments. The first animation shows normal crossing over, where the X and Y chromosomes exchange pieces only at their tips. The second animation shows a rare mistake in which the Y chromosome transfers a gene called SRY to the X chromosome, resulting in sex-reversed babies. Studies of sex-reversed individuals led researchers to identify the master switch for sex determination, the SRY gene, which tells a fetus to become a boy.

Quick look: In its modern sense, epigenetics is the term used to describe inheritance by mechanisms other than through the DNA sequence of genes. It can apply to characteristics passed from a cell to its daughter cells in cell division and to traits of a whole organism. It works through chemical tags added to chromosomes that in effect switch genes on or off.

Cancer cells are hungry. To feed their rapid growth and division, their metabolism changes. Moreover, they use sugar (glucose) in a different way to normal cells. This animation, created by Nature Reviews Drug Discovery, explores the key aspects of the altered metabolism in cancer cells and explains how these can be exploited for the development of new anticancer strategies.

Sulston worked alone, in silence, hunched over a microscope for eight hours a day. By studying and drawing worms of various ages, he figured out the ancestor and descendants of each of their cells. It was a monumental piece of science. Sulston mapped the complete history of an individual, the comprehensive family tree of a single body. "We had the entire story of the worm's cells from fertilized egg to adult," he later said, upon accepting the Nobel Prize for his work.

1:20 Stages of Mitosis, a promotional piece, begins with a fly-through of cells preparing to undergo mitosis (cell division).

Aneuploidy-the incorrect number of chromosomes in a cell-is extremely common in early embryos and is the primary reason for pregnancy loss. A report published today (April 9) in Science reveals that one cause of this aneuploidy-aberrant cell divisions in the embryo-is linked to a genetic mutation carried by the mother. Astonishingly, this mutation turns out to be very common and appears to have been under positive selection during human evolution.

"This modular case study tells the story of Dan and Annie, a married couple of Acadian ancestry who have a genetic form of deafblindness called Usher syndrome. They live in Southwest Louisiana, home of the largest population of DeafBlind citizens in the United States. Acadian Usher syndrome is caused by an allele of the USH1C gene that came to Louisiana with the first Acadian settlers from Canada who founded today's Cajun population. This allele's single nucleotide substitution creates an erroneous splice site that produces a defective cytoskeletal protein (harmonin) of the cochlear and vestibular hair cells and retinal photoreceptors. This splice site is the target of a promising gene therapy. The case study applies and connects Mendelian inheritance, chromosomes, cell division, vision and hearing, DNA sequences, gene expression, gene therapy and population genetics to a specific gene and its movement through generations of Dan and Annie's families.  After the introduction, each of the remaining sections can be used independently either for in-class team activities or out-of-class extensions or assignments over an entire year of introductory undergraduate biology. "

Reference page cellular facts: cell size, lenth, division, concentration, energy, diffusion, genomic information, and mutation rates.

7 minute video; mash up of multiple cool animation videos - 0-1:20   supercoiling DNA to chromosomes 1:25- 1:40 cell division/mitosis 1:45-2:50  DNA replication  2:55-4:45   transcription  4:50-6:55  translation 7:00-7:47

Basketball mitosis review game

6:45 video animation of types of cell division

This case study synthesizes students' knowledge of the central dogma and cell structure by examining a rare health disorder in order to understand protein targeting and its medical consequences. Students first identify the molecular alteration in affected members of a family with renal Fanconi syndrome as reported in the New England Journal of Medicine (2014). Students then use an online bioinformatics tool to analyze the wildtype and mutant proteins and examine their subcellular localization. Finally, students use this information to explain the symptoms of affected family members. The case is delivered with a PowerPoint presentation that includes a selection of brainstorming prompts and "clicker questions." Students complete a worksheet (included in the teaching notes) before class, making the activity suitable for a flipped classroom. A second worksheet (also included in the teaching notes) is completed during class. The case is written for an introductory biology course for majors, but could also be used as a unit capstone in a non-majors human biology course; the case is also scalable to upper division courses in physiology that specifically explore kidney function.

This directed case study follows two college roommates, Darrell and Anthony, who have just returned to school after winter vacation. They share that their ageing fathers are concerned about their declining faculties and are amused by their fathers' efforts to reverse the process.  Darrell's dad plays "brain games" on the computer while Anthony's father believes running will slow his memory decline. Intrigued, the roommates search through their biopsychology class notes to find out whether their fathers are correct. They review the topics of synaptic formation and plasticity, including axonal and dendritic development, and chemical factors in the brain that promote the survival and growth of neurons or stop the genetically programmed death of neurons. Based on research findings, students reading this case will decide whether Darrell and Anthony's fathers are correct in their assertions. The case is appropriate for a wide variety of courses including introductory anatomy or physiology, or for upper-division biopsychology, biology, or neuroscience courses.