This document explains the structure and function of cells, including the differences between animal and plant cells, and how cells specialize to perform specific functions.
Extract
[...] However, stimuli from the cell's environment (hormones, growth factors, cell interaction molecules) influence cells so that they can perform specific functions. The animal cell and the plant cell have similarities in their structure with the presence of a cell membrane, a nucleus, cytoplasm, mitochondria (organelles where cellular respiration takes place through the conversion of energy present in organic matter), ribosomes . However, they have differences. The plant cell has a cellulosic cell wall giving it a rectangular shape, a single large vacuole for storing water by osmosis to grow and maintain its shape. [...]
[...] Concerning the euglenes, I observe that their number is multiplied by three approximately over time days) in a medium devoid of OM and in a control medium. On the contrary, their number decreases slightly over the same period, in the absence of MM. However, I know that euglenes are organisms that perform photosynthesis. I deduce that the euglenes need MM present in their medium to multiply. The euglenes They therefore have an autotrophic metabolism: they use MM to produce their own MO. [...]
[...] It communicates with the cytoplasm through the nuclear envelope and directs cell division. It contains chromosomes consisting of DNA (deoxyribonucleic acid). DNA contains genetic information in the form of genes. The cell can thus ensure genetic stability during cell division but also transmit its genes hereditarily. DNA is a universal molecule in living organisms, with a double helix shape of 2 nm in thickness, obtained by coiling of the two DNA strands and maintained by bonds between the nitrogen bases of the opposing strands (figure 1). [...]
[...] Figure 3 : Structural organization of the animal cell Exercice 2 The graph represents the number of yeast in relation to the incubation time in days in a culture medium. I observe that the yeast do not divide in a medium without organic matter or without mineral matter over time (two days). On the contrary, their number increases proportionally in a control medium during the same period. Thus, I deduce that yeast need both MM and OM for their metabolism. Yeast are therefore cells with a heterotrophic metabolism. [...]
