Biomedicine pre study - Essay Example

The remaining portion of the cell except the nucleus or the knuckled region is the cytoplasm and consists of cytosol and various organelles essential for the functioning of the cell. Ribosomes are simple organelles in which protein synthesis occurs (Kent, 2000). The cell wall of plant cell is made up of cellulose while that of animal cell is made up of phospholipids. Such a cell wall allows the plant to take in large amounts of water through osmosis without being destroyed. Plant cells synthesise energy by means of photosynthesis during which sunlight is converted to energy.

For this purpose, plant cells have chloroplasts which have their own DNA and which direct the work of chloroplasts, These organelles are absent in animal cells and animal cells synthesise energy through metabolism of the food they take. Another major difference is the presence single large vacuole in the plant cells. Animal cells have small multiple vacuoles. Also, plant cells have a regular shape and the shape of animal cells varies greatly (Kent, 2000). DNA and RNA are the structures in the cell which carry inherited traits.

Inheritance mainly occurs due to meiosis. In this type of cell division, the genome of the diploid germ cell which has long segments of DNA organized in chromosomes undergoes two rounds of cell division resulting in four haploid cells. During division, replication of DNA occurs. Each of the four haploid cells contains one complete set of chromosomes which is half of the genetic content of the original cell. The haploid cells act as gametes and fuse with gametes of the partner. One gamete fuses with only one gamete of the partner .

This is known as fertilization and this leads to a new diploid cell or zygote. Thus chromosomes of each parent undergo recombination in a homologous manner during the process of meiosis and thus each zygote inherits DNA from both parents (Kent, 2000). The four most