Spemann Organizer

1. Many experiments were conducted during the 1950s and 1960s with chick embryos and they showed that two patches of tissue essentially controlled the development of the pattern of bones inside limbs.  Describe at

Organs begin to form in organogenesis. The embryo develops into a larval stage, the tadpole. Metamorphosis then turns the tadpole into a frog.

embryos through certain environments in order for each one to adapt to a job already determined

In a classroom setting, each student has a different way of learning. Physical and visual learning. Performing dissections enables those that are aimed more towards physical learning to get a more hands-on experience and to get a feel of the different textures, whereas the visual learners can get a three-dimensional imagery of the different systems and how they are arranged to work together.

The dissection of fetal pigs in the laboratory is extremely important as pigs are complex organisms with an internal structure much similar to the human body. This provides students to with the opportunity to receive insight on how their bodies work. In addition, they will also be given the opportunity to learn about evolution through the dissection of a pig.

into an early stage embryo while still in a test tube. Scientists place the early stage embryo into

Sus scrofa, or the domestic pig is a member of the class Mammalia and the order Artiodactyla. Since we as humans are also a member of class Mammalia, we have a good deal in common biologically with pigs, although we might not like to think so. Since we have a good deal in common, it is very helpful for us to study these animals both anatomically and physiologically. We do this when we test medicines on pigs, perfect surgical procedures on pigs, and even when we used to use pig valves for replacements in human hearts. Thus the pig is a first-rate example of a mammal and the purpose of this lab is to recognize the specific similarities between the pig and ourselves as humans. To accomplish this we

Charlene Forest is an associate professor in the Biology department at Brooklyn College, who dedicates her research in to trying to understand the mechanism behind the process of fertilization in algae, as well as what controls expression of gamete-specific genes. To do so, she must understand how sperm and egg gametes first recognize and then fuse with each other. Thus, in order to find what causes the fusion of these gametes, Forest’s lab is cloning genes that prevent the fusion of sperm and egg gametes. She hopes that her research on the fertilization process in algae will help understand the fertilization process in other organisms, particularly humans.

After embryo development, endosperm is growth to store nutrients. This happens after double fertilization, when the triploid nucleus of the ovule’s central cell divides. This causes the formation of a milky multinucleate “supercell”. This becomes multicellular after cytokinesis. Finally, when the cell walls are completed, the endosperm becomes solid.

animal in the early stages of growth when it’s basic structure and organ development is forming.

When an embryo should be considered an actual human has a variety of answers, “some have sought to reject that the early human embryo is a human being, according to one view, the cells that comprise the early embryo are a bundle of homogeneous cells that exist in the same membrane but do not form a human organism because the cells do not function in a coordinated way to regulate and preserve a single life”.(Siegel)

Lee and George support their argument by providing three important facts that differentiate a human embryo is, in fact, a human being. First, they say that sex cells and somatic cells are part of a larger organism while the human embryo is a complete or whole organism, though immature (14). Secondly, they say that the embryo is human and has all the characteristics of a human being but the sex and somatic cells are genetically and functionally different because they cannot develop

Xenopus laevis and Danio rerio are two models that are extensively used to study early embryonic development, in particular, neurulation. During this practical Danio rerio was used as the model, however the advantages and disadvantages of the use of both models will be discussed herein.

[1] "Development of the embryo begins at Stage 1 when a sperm fertilizes an oocyte and together they form a zygote."

The prenatal development generally refers to those processes which start at least 40 weeks prior to the birth of the child (1). However, the period of organogenesis happens during the third through the eight weeks of development and gives rise to the the three germ layers known as ectoderm, mesoderm, and endoderm. Those three germs layer will later on form specific tissues and organs. (2). The production and development of the organs also known as organogenesis begins thereafter the formations of the three organs (3). During he development of the different phases, which include growth, morphogenesis, and differentiation, the fetus is completely