Teacher Demo/Student Activity: Limit to Cell Size

41800307 - main blood cells in scale isolated on white background

41800307 – main blood cells in scale isolated on white background

Introduction 

Cells require a constant supply of glucose and oxygen to produce energy.  Cellular respiration occurs in the mitochondria of a cell. As a result of this process, large quantities of waste carbon dioxide must be expelled from the cell. All materials involved in this reaction are either imported or exported through the cell membrane by diffusion.

Students observe the effect of cell volume and surface area on the extent of diffusion of the sodium hydroxide solution through the “cell”.

teacher-demo-student-activity-limit-to-cell-size

How CRISPR lets us edit our DNA | Jennifer Doudna

Geneticist Jennifer Doudna co-invented a groundbreaking new technology for editing genes, called CRISPR-Cas9. The tool allows scientists to make precise edits to DNA strands, which could lead to treatments for genetic diseases … but could also be used to create so-called “designer babies.” Doudna reviews how CRISPR-Cas9 works — and asks the scientific community to pause and discuss the ethics of this new tool.

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