A. Title

Observation of Mitosis Phase and Chromosome Position in Allium cepa L.

B. PRACTICAL OBJECTIVES

At the end of this practicum, students are expected to be able to:

1. Recognize the phases of mitosis by observing the position of chromosomes.

2. Understand the stages in making squash method preparations used in microscopic observations.

C. TOOLS AND MATERIALS 

a). Tools

b). Material

D. WORK PROCEDURES

E. OBSERVATION RESULTS

F. DISCUSSION RESULTS

  In the 3rd practicum conducted on Wednesday, October 2, 2024, we conducted a mitosis observation practicum on Allium cepa L. In this practicum, the practicum participants were expected to be able to see the stages of mitosis and see the location of the chromosomes. However, in this practicum, our group was only able to see two of the four stages of mitosis. Namely in the prophase and telophase stages, we could not see all the stages of mitosis because there were several factors that made this practicum not go well.

  At the beginning of the practicum, the practicum participants were asked to prepare the tools and materials that had been ordered by the laboratory assistant, then the practicum participants were asked to sterilize the tools that would be used before placing the samples in the tools that had been provided. The first step we took was to place the onion bulbs in a petri dish filled with water until the roots grew. Cut the tip of the root that had grown with a razor, take the white part then place it in a watch glass and add 70% alcohol and let it soak for 2 minutes. After 2 minutes, the 70% alcohol was sucked up with blotting paper, then soak the roots in the H2O2 solution for 5 minutes. Then take the onion root pieces from the watch glass, then cut the tip (root cap) and place it on the object glass. The next step is to drip it with acetocarmine solution, then chop it using a rusty cutter, then cover it with a cover glass. Then grind it with your thumb or a blunt pencil tip. The preparation was passed over a spirit lamp. Finally, observe the stages of mitosis division under a microscope.

  In the end, our group only got the results of two of the four stages of mitosis, namely the prophase stage, which is the longest and most energy-consuming phase of mitosis. The events that occur during prophase are as follows: Chromatin threads become chromosomes, then the chromosomes double into two chromatids but are still attached to one centromere. and the second is the telophase stage. At this stage, we have entered the final stage of mitosis. At this stage, the chromosomes have arrived at their respective poles. The spindle threads begin to disappear and the nuclear membrane also begins to appear between the two separate groups of chromosomes.

DOCUMENTATION

Observation process under a microscope

Drying onion root tissue samples to make them easier to separate or flatten when making microscopic preparations.

A. Title

Diffusion and Osmosis Experiment based on Solanum tuberosum . The nature of the substance and the concentration of the solution are different.

B. Objectives of the Practical Work

This practicum was conducted to observe the processes of diffusion and osmosis.

C. Tools and Materials

D. Work Procedures

E. Observation Results

1). Diffusion

      The steps we took were to clean 4 beakers and then fill each beaker with 50 ml of water. After that we put 1 spoon of nutrisari spatula into 1 beaker and stirred it quickly and simultaneously with the third glass. The second glass we used the same measurement, which was 1 spoon of nutrisari spatula too, but in this second glass we did it without stirring like in the previous glass which was stirred. Then in the third glass, we put in 10 drops of food coloring using a dropper by stirring quickly and simultaneously with the beaker containing nutrisari which would also be stirred. In the fourth glass, we put in 10 drops of food coloring using a dropper without stirring. Then don't forget we also calculate the time using a stopwatch needed by the two solutions to mix with the solvent and we can find out the results of the experiment we did.

     Based on the results of observations on the diffusion process with the Nutrisari sample experiment as a substitute for CuSO4 Crystal material _and food coloring as a substitute for Eosin Solution material. A time difference was obtained in the stirred sample and the unstirred sample.

- Unstirred Nutrisari sample

- Stirred Nutrisari sample

- Unstirred food coloring

- Stir in food coloring

2). Osmosis

      In osmosis we use Solanum tuberosum tuber as a sample and then we measure it. After measuring it, we cut the potatoes into 2 equal parts. then we clean and dry both potatoes with tissue, and weigh them and calculate the weight of the potatoes. After going through the weighing process, we prepare a beaker glass and fill each beaker glass with distilled water and 50% NaCl solution as much as 50 ml. Continued by inserting the potatoes that have been weighed into distilled water and 50% NaCl solution simultaneously. Let the potatoes sit for 60 minutes.

- The process of soaking potatoes in NaCl and Aquades solution

- Potato weighing process

F. Discussion Results

Pada tanggal 25 september 2024, kami kelompok 5 telah melakukan pengamatan pada proses difusi dan osmosis. Pada proses difusi, kami menggunakan sampel nutrisari sebagai bahan pengganti Kristal CuSO₄ dan pewarna makanan sebagai pengganti  Larutan Eosin. Kemudian pada proses Osmosis, kami menggunakan tuber  Solanum tuberosum sebagai sampel kami. Praktikum ini diawali dengan menyiapkan segala alat dan bahan yang  sudah dipesan oleh asisten lab. Adapun alat dan bahan yang telah kami persiapkan  adalah pewarna makanan, nutrisari dan kentang. Untuk bahan lainnya telah  disediakan didalam laboratorium. Diawali dengan pengamatan pada proses osmosis. Pada osmosis kami  menggunakan tuber Solanum tuberosum sebagai sampel. Kemudian ada Larutan  NaCl 50% sebagai pelarut, aquades juga sebagai bahan yang penting dalam  pengamatan ini. Alat yang kami gunakan ada pelubang kentang, alat ini berguna  untuk mengambil tuber dari Solanum tuberosum dengan ukuran yang sama.  Langkah awal yang kami lakukan adalah melubangi kentang dan mengukur  kentang menggunakan mistar, dengan ukuran 2 cm. Setelah mengukurnya, kami  memotong kentang mejadi 2 bagian yang sama. kemudian kedua kentang tersebut  kami bersihkan dan keringkan dengan tisu, dan menimbangnya dan menghitung  berat dari kentang tersebut.

      - Setelah melalui proses penimbangan, kami mempersiapkan gelas beaker  dan mengisi masing-masing gelas beaker dengan aquades dan larutan NaCl 50%  sebanyak 50 ml. Dilanjutkan dengan memasukkan kentang yang sudah ditimbang  tadi kedalam aquades dan larutan NaCl 50% secara bersamaan. Diamkan kentang  tersebut selama 60 menit. Kami mengamati apa yang terjadi pada kentang tersebut, yang mana pada gelas beaker yang berisi larutan NaCl 50% lama kelamaan kentang tersebut mengecil dan yang awalnya mengapung diatas lama kelamaan mulai turun  kebawah. Kentang yang awalnya dengan panjang 2 cm dan berat 1,1916 gr  berubah menjadi 1,8 cm dan berat 0,8421 gr. Pada larutan NaCl 50% sel-sel kentang mengalami kekurangan air akibatnya kentang menjadi plasmolisis. Kondisi ini mengakibatkan tekanan turgor. Akibatnya, kentang menjadi lebih  empuk dan lembek. Sedangkan penurunan berat kentang terjadi akibat  perpindahan air dari sel-sel kentang kelarutan. Maka dari penjelasan dan  pengamatan kami, kami mendapatkan hasil hipertonik (plasmolisis).

      - Kemudian pada gelas beaker yang berisi aquades, kentang tersebut semakin lama agak membesar daripada bentuk awalnya. Kentang yang awalnya dengan panjang 2 cm dan berat 1,2922 gr berubah menjadi 2,2 cm dan berat 1,3755 gr Kentang mengalami yang namanya osmosis. Osmosis memungkinkan difusi molekul air menyeberangi membrane yang permeable terhadap air tetapi tidak permeabel terhadap bahan terlarut yang ada didalam air. Maka dari penjelasan dan pengamatan kami, kami mendapatkan hasil Hipotonik.

Next, observations on the diffusion process. In the diffusion process, we used a sample of nutrisari as a substitute for CuSO4 Crystals and food coloring as a substitute for Eosin Solution. The steps we took were to clean 4 beakers and then fill each beaker with 50 ml of water. After that, we put 1 spoon of nutrisari into 1 beaker and stirred it quickly. We filled the second glass with 1 spoon of nutrisari too, but in this second glass we did it without stirring. In the third glass, we put 10 drops of food coloring using a dropper by stirring quickly. In the fourth glass, we put 10 drops of food coloring using a dropper without stirring. Then we also did not forget to calculate the time needed for the two solutions to mix with water. Based on the results of observations on the diffusion process with the experiment of Nutrisari samples as a substitute for CuSO4 Crystals and food coloring as a substitute for Eosin Solution. The time difference was obtained in the stirred and unstirred samples. In the beaker glass containing the nutrisari, the stirred nutrisari material only needed 5 seconds to dissolve. While the unstirred nutrisari material needed 55 minutes to dissolve. The same thing happened to the food coloring sample, the stirred food coloring took 2 seconds to completely dissolve, while the unstirred one took 32 minutes to completely dissolve. This happens because of the movement of molecules or solutes from high concentrations to low concentrations. The difference in concentration in two solutions is also known as a concentration gradient. Even though there is no difference in concentration, the movement of molecules can still occur to achieve equilibrium. 

     According to Camphell (2010), diffusion and osmosis are included in passive transport. Where when a substance crosses a biological membrane without expending energy. In other words, diffusion and osmosis occur spontaneously. Passive transport is defined as the movement of substances across the cell membrane without expending energy. This transport goes down the concentration gradient. Passive transport can occur due to differences in concentration from outside and inside the cell so that molecules move through the plasma membrane or cell membrane.

Documentation

Solanum tuberosum Harvesting Process

Potato weighing process

The process of taking NaCl solution

The process of soaking potatoes in NaCl and Aquades solution

Potato length measurement process

A. Title

ANALYSIS OF DIFFERENCES IN THE STRUCTURE OF ANIMAL CELLS AND PLANT CELLS

B. Tujuan Prakritikum

  At the end of this practicum, it is expected that the practicum participants will be able to explain in detail the structure of animal cells and plant cells, and the practicum participants will be able to describe the parts of animal cells and plant cells, and be able to explain the differences between animal cells and plant cells based on the results of observations obtained from the practicum.

C. Tools and Materials

1. Microscope                                     
2. Drop pipette                                     
3. Object Glass                                  
4. Cover Glass                              
5. Toothpick
6. The inner membrane of the Allium Cepa bulb
7. Aquadest
8. Cheek Mucosa

D. Work Procedures

• Preparation of Plant Preparations 

Red Onion (Allium Cepa) Preparation

• Manufacture of Animal Preparations

Cheek Mucosa Preparation

E. Observation Results

NO	SAMPLE NAME	DOCUMENTATION	DESCRIPTION
1	Garlic Onion		After observing Allium cepa cells taken from a thin membrane on a red onion using a microscope with a magnification of 40x10, several parts of the cell can be seen, including the cell wall, nucleus and cytoplasm.
2	Cheek Mucosa		The structure of the cheek epithelial cells includes cell shape, cell nucleus, and cell membrane in the cheek mucosa. Cheek mucosa cells are usually not tightly arranged like other epithelial tissues. This is because sampling is done randomly. And the cell structure begins to be seen at a magnification of 100x10.

F. Discussion Results

Activity

• Red onion ( Allium Cepa )

 First of all, prepare the tools and materials to be used, then start slicing the onion skin thinly using a caterer to take the inner membrane of the red onion, then place it on a glass object and drip it using lugol's solution, then cover it with a cover glass then observe using a microscope with a magnification of 10x10 we have not gotten good results so we increase the magnification and 10x40. We did several samplings to get good results. Then observe and draw to write the results of allium cepa on the microscope, it can be seen that the red onion cells contain cell organelles such as cytoplasm, cell walls and nucleus, as explained by Nissafrieda (2018)

• Cheek Mucosa

prepare tools and materials. Then take the inner cheek mucosa using a toothpick to make it easier, we do this step slowly so as not to cause injury to the inside of the cheek, then place it on a glass object glass to be observed. Dropped with Aquadest liquid so that it is clearly visible when observed using a microscope. Based on the results of observations, the part that is very clearly visible is the cell nucleus. Then cover the sample using a cover glass so that it does not move when observed with a microscope with an initial magnification of 10 x10 but we have not been able to see the cells that must be observed so we try to increase the magnification of the microscope lens to a magnification of 100x10. Then it started to look so we observed and drew to write down the results. As explained by S Ristawati (2019)

Documentation

KESAN : PKKMB TAHUN 2024 SANGAT MENYENANGKAN, KARENA  BANYAK HAL BARU YANG KITA DAPATKAN YANG BELUM DI DAPATKAN KETIKA MASA SMA

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