The cell cycle of eukaryotes consists of alternation between growth and DNA replication (interphase), and DNA distribution and cell-division (mitosis or M-phase). This process is regulated by a complex network of biochemical reactions. A core part of this network, called the "Cell Cycle engine" is evolutionarily conserved. The dimer of CDK1 (a protein kinase) and Cyclin proteins (the regulatory components), called M-phase Promoting Factor (MPF), and its key regulatory proteins Cdc25 and Wee1, are central parts of this cell cycle engine. Maintaining the fidelity of the DNA during the cell cycle is critical for successful propagation of the cell lineage. In the presence of unreplicated DNA, the cell cycle engine''s progress into mitosis is slowed down (or halted) by regulation of MPF activity through Cdc25 and Wee1. This regulatory event, called the unreplicated DNA checkpoint, was modeled in a rudimentary fashion in the Novak and Tyson (1993) model of frog eggs. Since then, many new experiments have uncovered relevant parts of this network. Here, we include these parts into a detailed model of the unreplicated DNA checkpoint in the cell cycle of frog-egg extracts. This work and future studies of the unreplicated DNA checkpoint will lead to its better understanding and hopefully to some strategies for tackling cancer. / Master of Science

This diploma thesis deals with rebuild of manual drill-mill machine BF20L into CNC mill machine, 3D model of that and eventual control using PLC. All axes are powered by stepper motors, with encoders, connected to control cards and industrial computer from company Beckhoff. For this control is made full switchboard, supplemented by electrical wiring diagram. Program control along with visualization is made in software TwinCAT 3. Drill-mill machine can be controlled manually or automatically by program.

In this thesis I focused on the evaluation of the historical development of electronic kits in the Czech school system, and the survey of the current state of use of electronic kits in the subject Praktické činnosti (Practical Activities) on the second level of primary schools. The thesis also presents a comparison of different types of electronic kits using complex eva-luation criteria. Another part deals with design and implementation of a custom electronic kit intended for teaching the subject Praktické činnosti (Practical Activities), including the implementation of appropriate didactic instruction.