Most animals, including humans, have bilateral symmetry, which means our bodies are pretty symmetrical. At least on the ...

In the model, this is the grape. Cell membrane close cell membraneThis surrounds the outside of animal cells and controls what can enter and exit it.: In the model, this is the balloon.

Although unicellular, it exhibits a fascinating reproductive process that mirrors the embryonic stages of animals. During reproduction, C. perkinsii divides itself into a cluster of smaller cells ...

This internal left-right asymmetry is believed to begin at the very early stage of development -- when a tiny embryo is divided into two parts during a process called gastrulation. This process ...

Figure 1: Specific cell associations that define the stages of the cycle of the seminiferous epithelium are present within distinct regions that exhibit differential light absorption patterns.