Good morning students! Today, we're discussing cells, the building blocks of life. Can anyone tell me why cells are important?

Absolutely! Cells are not just structural units. They also perform vital functions necessary for life. Remember, everything alive is made of cells—think of it as 'Cell: The Unit of Life'.

Exactly! Tasks such as digestion, excretion, and protection happen at the cellular level. Let's recall that cells can be unicellular or multicellular. Can anyone name an example of a unicellular organism?

Great! Remember that amoebas function independently as single-celled organisms.

Yes, precisely! Humans and many animals are multicellular and have specialized cells that perform specific functions. Let's summarize: Cells are fundamental to life because they provide structure and facilitate necessary functions.

Now, let’s differentiate between prokaryotic and eukaryotic cells. Who can tell me one major difference?

Exactly! Prokaryotic cells are simpler, like bacteria. Their genetic material floats in the cell, and they lack membrane-bound organelles. Can anyone name a prokaryotic organism?

Correct! Now, eukaryotic cells, on the other hand, are more complex and have various organelles, including a nucleus. Can someone mention a eukaryotic organism?

Exactly! And they even have specialized structures inside them like mitochondria for energy production. Remember: 'Eukaryotes are Complex, Prokaryotes are Simple.'

Let’s go deeper into cell structure. What do all cells have that is essential for establishing their boundary?

Correct! The cell membrane is semi-permeable and controls what enters and exits the cell. Now let’s talk about what’s inside a eukaryotic cell?

Exactly! The nucleus contains genetic material. Mitochondria are known as the powerhouse of the cell for producing energy. How about in prokaryotic cells?

Spot on! Prokaryotic cells mainly have a ribosomal structure for protein synthesis. Remember the acronym 'MRS GREN' to remember the functions of life performed by all cells: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition.

Now let’s discuss how size and shape of cells vary. Why do you think cells look different?

Exactly! The structure of a cell is closely related to its function. For example, nerve cells are long and branched to transmit signals effectively. Can anyone think about the smallest cell?

Right! And what about the largest?

Correct! It’s fascinating how size can vary so much. Remember: 'Shape fits function.' Cells have specialized shapes that help them perform their distinct roles.