There are many different types of cells in animals. Each type is specialised for a particular role. These ensure that the organism functions as a whole. The head of the sperm contains the genetic ...

Tissues are ensembles of similar or compatible types of animal or plant cells that together carry out a specific function. In the human body there are four categories of tissues: epithelial ...

the marked stem cells that produced the white sectors in Figure 3 gave rise to all the different cell types that make up a leaf). Do similar mechanisms operate in plant and animal stem cells to ...