Lafayette sees Mitosis through Microscopes

Mitosis: Making Copies

In today’s lesson, Lafayette students learned how cells clone themselves through the process of mitosis and got to use microscopes to see the small cellular world magnified 40 times. Students learned that mitosis – the act of one cell splitting to become two identical cells – is how multi-cellular organisms are built from a single cell at the beginning of life. Students were very excited to get to use a microscope to look at the cells that form onion root tips.  With careful examination, students learned to recognize DNA structure in the onion cells and identify the different phases of the cell cycle.

Mitosis is a complicated process for a cell, and there are about 5 recognizable phases that can be observed under a microscope.

For a cell to clone itself, DNA in the nucleus first must be duplicated. This is INTERPHASE step, and creates extra DNA so that the two cells that result each get their own copy.  Next, the duplicated DNA forms chromosome pairs during PROPHASE, and individual chromosomes are visible under the microscope. Students think it’s neat to see the DNA inside cells with their own eyes. The chromosomes are then nicely arranged in the center of the cell during METAPHASE, and the nucleus breaks apart so that the DNA can be separated.  After metaphase, and without a nucleus, the cell moves half of the DNA to one side of the cell, and half to the other side. This is ANAPHASE.  In the final step TELOPHASE, a nucleus forms around each DNA set, and a single cell has two nuclei. Cells are noticeably larger in size because the two nuclei inside take up so much space. Finally during CYTOKINESIS, the cell pinches in half. Each nucleus then has a full cell membrane surrounding it, complete with cytoplasm and organelles! Now the two cells begin to go back to work and do their biological duties.

Students learned an important lesson, that without mitosis, our cuts wouldn’t heal and our bodies wouldn’t grow!

Ask your student what their favorite phase of mitosis is when you see them!

La Mitosis: haciendo copias

En la lección de hoy hablamos acerca del copiar. No sobre copiar la tarea de nuestros compañeros, sino de copiar células. Los estudiantes aprendieron que la mitosis, proceso por el cual una célula se divide en dos idénticas, ocurre todo el tiempo en los humanos.

Durante la mitosis, el núcleo de una célula se divide primero para luego comenzar el proceso de crear dos células que son completamente idénticas a la célula parental. Este tipo de división celular es importantísimo para la vida en la Tierra. Sin la mitosis, nuestras heridas no sanarían y nuestros cuerpos no crecerían.

Pregúntele a su hija o hijo cual fue su fase favorita de la mitosis.