Introduction to the
Nano-electromechanical
Systems
授課教師:許藝菊
學生:許孟智
1.(上面細胞是動物，下面是植物)
2.Differences between Plant & Animals Cells
Differences:
Key difference: Animal cells do not have rigid cell walls and chloroplasts, and they have smaller vacuoles.
Plant cells have a rigid cell wall and chloroplasts and have a large central vacuole.
The main difference between an animal cell and a plant cell is that, plant cells have a cell
wall, which the animal cell lacks. The cell wall which is made up of cellulose gives the plant
cell rigidity resulting in a fixed, rectangular shape. Animal cells lack the rigidity hence, they
tend to have a round and irregular shape. Animal cells tend to vary greatly in appearance.
The cell wall allows high pressure to build inside of the plant cell without bursting. Due to
this, the plant cell is able to accept large amounts of liquid through osmosis without bursting.
Animal cells, which only have a thin membrane restricting access to the cell, tend to burst if
they absorb too much extra water.
Both animal cells and plant cells have a defined nucleus, which contains chromosomes. The
nucleus is protected and surrounded by cytoplasm, a watery or gel-like liquid that holds all
the organelles in place. The cytoplasm, in turn is held in by the cell membrane.
However, all animal cells have centrioles whereas only some lower plant forms have it. Also,
plant cells tend to have one large central vacuole that can take up to 90% of cell volume.
Animal cells tend to have one or more small vacuoles. Vacuoles contain waste materials,
water, and nutrients that can be used or secreted as necessary. In plant cells, vacuoles store
water and maintain turgidity of the cell. In animal cells, they store water, ions and waste.
Another difference among them is that plant cells have chloroplasts for photosynthesis,
which allows them to covert sunlight into food for the cell. Chloroplasts have its own DNA
and tend to direct their own work. Animal cells lack chloroplasts and hence this ability,
which is why we can’t live off of sunlight, sadly.
Further comparison between animal cells and plant cells:
Animal Cell
Plant Cell
Type of cell
Eukaryotic
Eukaryotic
Cell walls
No cell walls
Rigid cell walls
Shape
Round (irregular shape)
Rectangular (fixed shape)
Organelles
Cell membrane
Cell membrane
Nuclear membrane
Cell wall
One or more small vacuoles
Nuclear membrane
Centrioles
Plasmodesma
Cytoplasm
Large Vacuole
Endoplasmic Reticulum
Plastids
Ribosomes
Chloroplast
Mitochondria
Leucoplast
Golgi Apparatus Microtubules/
Chromoplast
Microfilaments
Golgi Bodies
Flagella in some cells
Ribosome
Lysosomes
Endoplasmic reticulum
Nucleus
Mitochondria
Cilia
Lysosome
DNA
Cytoplasm
Nucleus
DNA
Chromatin
RNA
Cytoskeleton
Nucleolus
3.How would you determine whether a new organism
you discovered was a eukaryote or prokaryote
Many aspects of endosymbiosis still aren't understood. For example, how did the first endosymbiont get
inside its host? Was the host trying to eat the endosymbiont? If so, why wasn't the endosymbiont digested?
Or was the endosymbiont trying to infect and exploit the host, the way the x-bacteria originally invaded their
amoebae hosts?
We might get closer to answering these questions if we knew what species of bacteria came together to make
the original eukaryotic cell. Biologists are in the process of figuring this out using evidence provided by
comparing the gene sequences of different organisms. In general, the more similar two organisms' genes are,
the more recently their two lineages split apart from one another. If two organisms have been evolving
separately for a very long time, and have a distant common ancestor, they are likely to have evolved lots of
differences between their gene sequences. So by comparing the genetic sequences of different organisms,
biologists can piece together their family tree — who is related to whom.
Biologists have even studied the DNA in mitochondria to figure out how they are related to free-living
bacteria. These studies have shown, first, that all mitochondria are descended from one original
mitochondrion — that is, endosymbiosis of a mitochondrion only happened once — and second, that
mitochondria are most closely related to a bacteria called Rickettsia prowazekii. This parasitic bacterium
causes epidemic typhus and is primarily transmitted through bites of animals such as fleas.