Day 25: Using Microscopes/Chapter 6

Today we learnt how to properly use  microscopes while learning about cells. We looked at some really cool things. We looked at our cheek cells, plant cells, and cells from the creatures from our aquarium.

Here is a picture from the digital microscope we have and it shows the chloroplast in the plant cells.

Chapter 6 from Your Innner Fish was about how scientists like von Baer and Haeckel studyed embroylogy. embroyology is the study of embroyos whic we briefly discussed in the study of evolution and how embryos at an early stage in a lot of life forms shows the close links between us and pigs for example. There can be three layers to an embroy the endoderm, the mesoderm, and the ectoderm. Each layer is where diferrent organs start to develop from that starts at four weeks after
conception.

A embryologist named Spemann later experimented with embryos and found something really
intresting.He split an embryo of a newt and sepreated it and found that in both pieces a complete viable newt grew. Later his student Mangold cut a piece off of an embroyo that contained the important three germ layer. Mangold moved it and a newt  was formed with two heads. This patch was known as the organizer. People then later looked at DNA especially in flies and saw that the DNA was organized. There was points where there is DNA for devleopment like for the head and then the body all in an order. They looked at this sequence and it was nearly identical in every species and the sequence is called homeobox and the eight genes that contain this homeobox are called hox genes. Scientists were looking for these hox genes in a frog and noticied a gene in the organizer that affect embryo development. Another gene was found called Noggin that did what the organizer did and duplicated a head on a species. Noggen and the hox genes play a role in the organizer.

This is what the newt can look like after the organizer gene is transplanted: