F.4 Bio please help!!! 20點!!!

1. Prokaryotics contains cell wall but, it's quite different from that of plants. Prokaryotes' cell wall mainly contains peptidoglycan. However, plants usually have cellulose as the major component of cell wall.

2. Both red blood cell and xylem cell are eukaryotic cell.
Because they contain a true nucleus, They contain membrane-bounded organelles.

3. Eukaryotic: DNA are enclosed in the nucleus. Contains membrane-bounded organelles.

Prokaryotic: DNA lies freely in the cytoplasm. Does not contain membrane-bounded organelles.

1) "Most of the prokaryotic cells have cell wall. (However, their cell wall does not
contain cellulose as plant cell wall does.)"

What does the sentence in ( ) mean?
→它是指原核細胞的細胞壁是蛋白，而植物界的壁是纖維素做的。

2013-09-26 12:03:09 補充：
2)Red blood cell and xylem cell are prokaryotic or eukaryotic cell?
→真核。
And Why?
→因為原核真核是從分類上來區分的，不是沒有細胞核的細胞叫原核。
3)What is the main and most important factor to distinguish prokaryotic and
eukaryotic cell ?
→應該就是有核無核。

1.) Difference in cell wall of plants and prokaryotes can be distinguish by their chemical structure. Plant's cell wall is made out of cellulose which are chains of polysaccharides of beta glucose linked by glycoisdic bonds of carbon group 1 -> 4. Prokaryote's cell wall is formed by peptidoglycan or murein by polymers of amino acids and sugars. It is called "cell wall" for both because their functions are rather similar in withstanding osmotic pressure and giving the cells their shapes.

2.) Although red blood cell, also called erythrocytes, does not contain a nucleus and are lack of some organelles that exist in normal cells. They are differentiated cells to perform their function of carrying oxygen. It is still consider as eukaryotic as it is presence in animals, absence in prokaryotes.

3.) Eukaryotic cell: size 10-100 micrometer. Multi-cellular, more than one chromosome, DNA is wrapped by proteins (histones), bounded organelles such as nucleus, lysosomes, peroxisomes, endoplasmic reticulum, mitochondria, golgi apparatus, chloroplasts (plants), larger ribosomes than prokaryotes etc.
Prokaryotic cell: size 1-micrometer. Absence of nucleus and other bounded organelles. Unicellular. Smaller ribosomes than eukaryotes.