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How do nucleosomes keep our DNA from reaching the sun?

How do nucleosomes keep our DNA from reaching the sun? | IB Biology | Scoop.it
A key concept in science is molecular scale. DNA is a fascinating molecule in this regard. While we cannot “see” DNA molecules without the aid of advanced technology, a full length DNA molecule can be very long. In human cells, other than sperm and eggs, six billion base pairs of DNA are packaged into 22…
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The problem is that the small dimensions are almost impossible to imagine. Naked DNA is about 2nm wide. Basically invisible to unaided human eyes. Fun

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IB Biology
Concepts, terminology, and other stuff for IB biology classes.
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Shallow Origins

Shallow Origins | IB Biology | Scoop.it
In finding answers to the mystery of the origin of life, scientists may not have to dig too deep. New research is shedding light on shallower waters as a possible location for where life on Earth began.
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Friday Cephalopod: It's not really an alien

Friday Cephalopod: It's not really an alien | IB Biology | Scoop.it
Well, cool. We've got preliminary analysis of the octopus genome, and it's full of tantalizing goodies, but it's very preliminary, and the Nature news and comment left me unimpressed. One of the th...
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Nice work that shows that divergence can lead in many directions. More genes than humans? Seems divergence of preexisting gene networks for development - not simply duplication. Cool animals :)

 

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Our unsustainable habit of hunting and fishing only for adult animals

Our unsustainable habit of hunting and fishing only for adult animals | IB Biology | Scoop.it
Unlike other predators, humans kill adults and predators, skewing populations.
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Ecosystems with predators and prey have usually had very long periods of time for adaptation to take place. Human hunting practices operate on a different timescale: our population growth, use of technology, and spread across the globe have outstripped the ability of the hunted populations to adapt to us. Our strategy of preying on adults is the opposite of the strategy that has evolved in many ecosystems, which is why it causes such complete havoc

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Octopus’ sophistication driven by hundreds of previously unknown genes

Octopus’ sophistication driven by hundreds of previously unknown genes | IB Biology | Scoop.it
Complex behaviors and a distinctive body plan enabled by a large, unfamiliar genome.
jlinzel's insight:

Interesting.

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The 'living concrete' that can heal itself - CNN.com

The 'living concrete' that can heal itself - CNN.com | IB Biology | Scoop.it
We have invented bioconcrete -- that's concrete that heals itself using bacteria," he says.
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P-Value Interpretation

P-Value Interpretation | IB Biology | Scoop.it
If all else fails, use "significant at p>0.05 level" and hope no one notices. -xkcd by Randall Munroe I can't say that I ever thought about doing this, but I can admit feeling enormous stress pr...
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Free Speech vs. Hate Speech

Free Speech vs. Hate Speech | IB Biology | Scoop.it
A Texas art exhibit was meant to express hatred, not to strike a blow for freedom, and can only worsen religious tensions.
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Sandwalk: Molecular Evolution Exam - April 2015

Sandwalk: Molecular Evolution Exam - April 2015 | IB Biology | Scoop.it
Molecular Evolution Exam - April 2015 Here's the final exam in my course. Students have to answer the first two questions and three of the next five questions. How would you do?
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Beyond Bar and Line Graphs: Time for a New Data Presentation Paradigm

Beyond Bar and Line Graphs: Time for a New Data Presentation Paradigm | IB Biology | Scoop.it
A systematic review of research articles reveals widespread poor practice in the presentation of continuous data. The authors recommend training for investigators and supply templates for easy use.
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Editing Human Embryos: So This Happened – Phenomena: The Loom

Editing Human Embryos: So This Happened – Phenomena: The Loom | IB Biology | Scoop.it
Earlier this week, Chinese researchers reported that they edited the genes of human embryos using a new technique called CRISPR. While these embryos will not being growing up into genetically modif...
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Sheep as models for diabetes

Sheep as models for diabetes | IB Biology | Scoop.it
Insulin is a major hormone responsible for regulating blood sugar. Its main function is to lower sugar by increasing glucose uptake into muscle and fat cells. Insulin resistance is the hallmark of type 2 diabetes and occurs when tissues in the body are not able to respond to insulin resulting in sustained elevations in blood sugar,…
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Mary's Monday Metazoan: Shhhh. I'm in disguise.

Mary's Monday Metazoan: Shhhh. I'm in disguise. | IB Biology | Scoop.it
This leafhopper is a myrmecomorph – it has sprouted lumpy dark extensions of its carapace that resemble an ant. It spends its whole life living in a costume!
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Why is the scientific world abuzz about an unpublished paper? Because it could permanently change human DNA

Why is the scientific world abuzz about an unpublished paper? Because it could permanently change human DNA | IB Biology | Scoop.it
A Chinese study could mark the first time a human embryo's genetic line is so altered the changes would carry through to future generations
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MH's curator insight, April 7, 2015 3:55 AM

Un article scientifique chinois est en préparation sur la modification de l'ADN d'un embryon, transmissible aux descendants. Cela reviendrait à  modifier le patrimoine génétique de toute la descendance de l'embryon : il deviendrait possible de modifier le code-source de l'humain. Les enjeux éthiques sont majeurs.

 

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Origin of life emerged from cell membrane bioenergetics

Origin of life emerged from cell membrane bioenergetics | IB Biology | Scoop.it
A coherent pathway which starts from no more than rocks, water and carbon dioxide and leads to the emergence of the strange bio-energetic properties of living cells, has been traced for the first time in a major hypothesi
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Why sex? Experiments on fruit flies suggest it evolved to resist infection

Why sex? Experiments on fruit flies suggest it evolved to resist infection | IB Biology | Scoop.it
Of course there's a proximate reason, at least in our species, to the question above: "Why sex?" That answer is fatuous but true: "Because it feels good." Of course it feels good—because pleasurabl...
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What happens when 'the blob' meets Godzilla El Niño? Climate chaos and more hot, dry weather for B.C.

What happens when 'the blob' meets Godzilla El Niño? Climate chaos and more hot, dry weather for B.C. | IB Biology | Scoop.it
'It starts to sound really science fiction, but... we haven’t seen anything like this before,' one climate scientist said of the pending perfect storm of climate confluence
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The Cambrian Explosion’s Strange-Looking Poster Child

The Cambrian Explosion’s Strange-Looking Poster Child | IB Biology | Scoop.it
For years, scientists struggled to explain the mysteries of a worm named Hallucigenia, but two new studies explain some of its quirks, and found it some cousins.
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Some gene conceptions and misconceptions

Some gene conceptions and misconceptions | IB Biology | Scoop.it
Any geneticist who has discussed genes with friends and family knows that there are a lot of misconceptions floating around out there. This is understandable - genetics involves some tricky concept...
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Circling the drain, the New York Times labels the Texas cartoon exhibit "hate speech"

Circling the drain, the New York Times labels the Texas cartoon exhibit "hate speech" | IB Biology | Scoop.it
It's a sad day when the New York Times, a bastion of free speech during Watergate and the publication of the Pentagon Papers , tarnishes its image by sort-of-excusing the Muslim attack on Pamela Ge...
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The Difference Between Bigotry and Blasphemy

The Difference Between Bigotry and Blasphemy | IB Biology | Scoop.it
Telling provocateurs that they cannot attack the religious beliefs of others simply serves to validate their darkest predictions.
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Lancet accused of 'anti-Israel hate propaganda' over its coverage of Gaza conflict

Lancet accused of 'anti-Israel hate propaganda' over its coverage of Gaza conflict | IB Biology | Scoop.it
One of the world’s oldest and most venerable medical journals is under attack from an international group of more than 500 doctors over its coverage of the humanitarian disaster caused by the Israeli-Palestinian conflict.
jlinzel's insight:

I don't want to take sides in an issue I know very little about. I will offer up an opinion that if the journal is getting heat from BOTH sides at different times, then its probably straddling the fence well. However, I'm not sure it should always straddle the fence. Maybe thats a new logical fallacy. 

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Never Settling Down: Frequent Changes in Sex Chromosomes

Never Settling Down: Frequent Changes in Sex Chromosomes | IB Biology | Scoop.it
Sex Determination Is Labile

Most animals come in male and female forms with many obvious visible and physiological differences. Cytologists long ago noticed that male and female karyotypes also often differ, with one sex having two distinct or heteromorphic sex chromosomes and the other having two copies of a single monomorphic sex chromosome. In many organisms including mammals and Drosophila, males are heterogametic with the X and Y chromosomes, while females are homogametic with two X chromosomes. In birds, butterflies, and other species, the opposite pattern is found where females are heterogametic (ZW chromosomes) and males are homogametic (ZZ chromosomes). It was also appreciated long ago that the genetic basis of sex determination is remarkably variable. For example, although mammals and Drosophila have the same sex chromosome karyotypes, sex determination depends on a dominant Y-linked male determiner in the former and a system of dosage-dependent, X-linked female determiners in the latter [1,2]. Then there are curious cases like houseflies, where different populations have been found having male determiners on different chromosomes [3]. Beyond even this variation are some amphibians and reptiles that determine sex based on environmental signals [4]
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45 years after Apollo 13: Ars looks at what went wrong and why

45 years after Apollo 13: Ars looks at what went wrong and why | IB Biology | Scoop.it
You’ve probably seen the film—but the reality is a lot more complicated.
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How malaria is evolving to survive our most potent drug

How malaria is evolving to survive our most potent drug | IB Biology | Scoop.it
Mutations stabilize a protein that our best drug targets.
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Modern genetics confirm ancient relationship between fins and hands

Modern genetics confirm ancient relationship between fins and hands | IB Biology | Scoop.it
UChicago's Neil Shubin and team have documented the evolutionary adaptations necessary for ancient lobe-finned fish to transform pectoral fins used underwater into strong, bony structures, such as ...
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