Induced pluripotent stem cells

Induced pluripotent stem cells, commonly abbreviated as iPS cells or iPSCs are a type of pluripotent stem cell artificially derived from a non-pluripotent cell, typically an adult somatic cell, by inducing a "forced" expression of certain genes and transcription factors.These transcription factors play a key role in determining the state of these cells and also highlights the fact that these somatic cells do preserve the same genetic information as early embryonic cells.The ability to induce cells into a pluripotent state was initially pioneered using mouse fibroblasts and four transcription factors, Oct4, Sox2, Klf4 and c-Myc, in 2006.This was then followed in 2007 by the successful induction of human iPSCs derived from human dermal fibroblasts using methods similar to those used for the induction of mouse cells. These induced cells exhibit similar traits to those of embryonic stem cells (ESCs) but do not require the use of embryos. Some of the similarities between ESCs and iPSCs include pluripotency,morphology, self-renewal ability, a trait that implies that they can divide and replicate indefinitely, and gene expression.

Evaluating Ecosystems in “Lion King” 

Authors: Philip Durkin and Susanne Coleman
Grade Level: 5

For additional free online lessons integrating media literacy and critical thinking into the curriculum, go towww.projectlooksharp.org.

Summary: 
Students will view the first scene from the “The Lion King” during which baby Simba is introduced. They will analyze the interactions or relationships they observe between the living things in each environment and infer which relationships are realistic and which are fictional and explain their reasoning.

Key terms: ecology, biotic factors, abiotic factors, population, community, ecosystem, symbiosis, mutualism, commensalism, parasitism, predator-prey

Objectives:

• Students will review the terms biotic and abiotic by identifying the biotic and abiotic factors they observe in the savanna and reef ecosystems in multiple media forms.
• Students will describe some of the interactions or relationships they observe between the living things in each environment and will infer whether each interaction represents an example of mutualism, commensalism, parasitism or a predator-prey relationship and offer evidence that supports their inference.
• Students will infer which relationships (in media represt

Pasteur Swan Neck Flask Experiment

Pasteur Swan Neck Flask Experiment

In his famous experiment, Louis Pasteur used a special flask whose neck was shaped like an S or the neck of a swan, hence the name "Swan Neck Flask." He put a nutrient rich broth in the flask, which he called the "infusion." He then boiled the infusion killing any microorganisms which were already present. Then he allowed the infusion to sit. Because of the shape of the flask, the infusion was exposed to air. However, dust particles and other things in the air never made it into the infusion. Because they were trapped in the curve of the Swan Neck Flask. No matter how long he allowed the flask to sit, microorganisms never appeared in the infusion. However, if he tipped the flask and allowed the things trapped in the neck to get into the infusion then microorgranisms began to appear in the infusion and multiply rapidly. This demonstrates that microorganisms do not appear as a result of Spontaneous Generation. Instead, they are introduced into food through dust particles and other things that happen to land on the food.