Eukaryotic Cell Lab Report

Differentiating Between Prokaryotic and Eukaryotic Cells, Distinguish Among Plant, Animal, and Protist Cells, and Identifying the Organelles that are Evident in Them

Introduction There are two different types of cells, prokaryotes and eukaryotes. Prokaryotes, such as bacteria, lack a nuclear membrane and other membrane bound organelles. Their genetic material consists of a single molecule of singular DNA. Eukaryotes, such as plant and animal cells, have a nuclear membrane and other membrane bound organelles. Their genetic material consists of one or more linear strands of DNA. Eukaryotic cells have a nucleus, cytoplasm, and a plasma membrane surrounding the cell. The typical plant cell has in addition a cell wall, a rigid structure made up of cellulose that surrounds the plasma membrane. Most animal cells are mostly filled with cytoplasm, whereas the plant cell has much of its volume taken up by a central vacuole containing water, salts, sugars and other compounds. The purpose of this experiment is to differentiate between prokaryotic and eukaryotic cells. Also to distinguish among plant, animal, and protest cells and identifying the organelles that are evident in them.
Materials and Methods A wet mount with a sample of Elodea (a common pond weed) was prepared. The wet mount is prepared by placing a drop of water on a glass slide. A very small piece of the Elodea is placed in the water and covered with a slip cover. The slide was then placed under the light microscope and observed for cell shape, and identifying the different organelles evident in the plant. The slide was kept on the microscope stage until it became warm. After a few minutes the slide was observed for the movement of the chloroplasts. The movement of the chloroplasts was also recorded. A wet mount with a sample of an onion cell was prepared. The wet mount is prepared by placing a drop of water onto a glass slide. One thin layer of the onion was placed in the drop of water. One drop of the Neutral Red was put on the slide to stain the onion. The slide was placed under the light microscope and observed for shape by focusing up and down through the layers. It was also examined for what type of organism it was and the cellular organelles observed. A wet mount with a sample of a potato shaving was prepared. The wet mount is prepared by placing a drop of water onto a glass slide. Using a scalpel blade, a small portion was thinly sliced from the potato and placed on the slide. A drop of iodine was then added to the slide to stain the wet mount. Iodine will stain the starch granules. The slide was then place under the light microscope and observed for shape and various layers by focusing up and down through the layers. It was also examined for what type of organism it was and the cellular organelles that were present. A wet mount, with a sample of a cheek cell, was prepared. The wet mount was prepared by placing a drop of water onto a glass slide. The cheek cell was obtained by gently scraping the inside of the human cheek with a toothpick. The toothpick was then placed in the drop of water on the slide to transfer the cells. The cheek cell was then stained with one drop of methylene blue. The slide was then placed under the light microscope and observed for shape and layers by focusing up and down through the layers. Two commercially prepared slides were observed. They were a prepared slide of a Paramecium caudatum and an Ameba proteus. The slides were place under the light microscope and observed for the shape and various layers by focusing up and down. They were both examined for what cellular organelles were present.
Results
The results for the organisms observed, the type of organism, and what cellular organelles were observed can be seen in Data table 1.
Table 1.
Organism or slide observed Type of Organism (plant, animal, protist) Cellular organelles observed
Elodea plant cell wall, chloroplast, cytoplasm, nucleus
Onion plant cell wall, nucleus, cytoplasm
Potato plant amyloplasts, cell wall
Human epithelial cells (cheek cells) animal nucleus, cytoplasm
Paramecium protist nucleus, vacuoles, cillia
Ameba protist nucleus, cytoplasm small intestine animal nucleus, chromatin
Blood animal cytoplasm

Discussion When viewing the Elodea (also known as pond weed) it was easy to distinguish it was a plant cell due to its rectangular shape. The cellular organelles that were observed were a cell wall, chloroplast, cytoplasm, and a nucleus. The nucleus was located off to the side of the cell. This was assumed to be because of the large central vacuole. As the slide began to get warm, after sitting on the stage for a while, the chloroplast began to move in a clockwise motion around the cell. The warmer the slide became the faster the chloroplast moved. The onion cell was also distinguished as a plant cell due to its rectangular shape. It was stained with Neutral Red it accumulates in the cytoplasm of the cell. The cellular organelles that were observed were a cell wall, nucleus, and cytoplasm. The onion cell has no central vacuole so the nucleus in this plant cell was located in the middle of the cell. The potato was determined to be a plant cell. The cellular organelles that were observed were the cell wall and amyloplasts. The potato was stained with iodine which turns the starches in the potato black. Many amyloplasts were observed. Amyloplasts are plastids where starch is stored. The cheek cell was determined to be an animal organism. The cellular organelles that were observed were the nucleus and cytoplasm. Four commercial slides were observed. They were a paramecium, ameba, small intestine, and blood. The paramecium, when examined under the light microscope was determined to be a protest. The cellular organelles that were observed were the nucleus, vacuoles, and cilia. The ameba was determined to be a protist as well, with the cellular organelles nucleus and cytoplasm both present. The small intestine was determined to be an animal cell. The cellular organelles that were present were the nucleus and chromatin. The blood was determined to be an animal cell with only cytoplasm that was able to be seen. Eukaryotic cells are a type of cell more complex than their counterparts, prokaryotes. Prokaryotes include simple bacteria, while eukaryotes make up all fungi, animals, plants and protists. Prokaryotic and Eukaryotic cells make up all known terrestrial life.