1.2.a Describe and interpret electron micrographs and drawings of typical animal and plant cells as seen with the electron microscope.
1.2.b Recognise the following cell structures and outline their functions: cell surface membrane, nucleus, nuclear envelope and nucleolus, rough endoplasmic reticulum, smooth endoplasmic reticulum, Golgi body (Golgi apparatus or Golgi complex), mitochondria (including small circular DNA), ribosomes (80S in the cytoplasm and 70S in chloroplasts and mitochondria), lysosomes, centrioles and microtubules, chloroplasts (including small circular DNA), cell wall, plasmodesmata, large permanent vacuole and tonoplast of plant cells.
- The two main types of cells are prokaryotic cells, e.g. bacterial cells, and eukaryotic cells, e.g. animal and plant cells.
- Eukaryotic cells possess nuclei that contains DNA.
Here we will discuss the structure and function of eukaryotic cells (that means animal and plant cells) in detail!
- Ultrastructure: very detailed structures (i.e., organelles) found within cells. In an electron micrograph, very fine (small) structures of a microscopic object can be seen because electrons are easily absorbed by the object.
- Organelles: functionally and structurally different parts of a cell.
- Compartmentalised: surrounded by membranes. Organelles are compartmentalised to separate their functions from the surrounding cytoplasm.
⚠️📝Note and remember the above definitions for GCE CIE Biology exams!
This is an example of an animal cell seen under an electron microscope:
This is an example of an plant cell seen under an electron microscope:
EUKARYOTIC CELL STRUCTURES AND FUNCTIONS 🧬:
A typical animal cell (left) and plant cell (right) are made up of the following organelles:
Below you will find a summary that will come in useful to understand the structures and functions of typical animal cells:
In addition to the above structures, except centrioles and microvilli, plant cells also comprise the following:
As you can see from the tables above, eukaryotic cells comprise organelles that play very important roles in cellular function!
⚠️⚠️ For your GCE CIE Biology exams: it is important to be able to label the different structures/organelles of plant and animal cells and outline their functions.
Phew! All done! 🤙
References:
Jones, M., & Parkin, M. (2018). Cambridge International As and A level biology. Cambridge: Cambridge University Press.
Walpole, B., Merson-Davies, A., & Dann, L. (2013). Biology for the IB Diploma Coursebook. Cambridge: Cambridge University Press.