Junior high school biology second volume mid-term examination paper

Plant DNA extraction mainly involved the following processes: 1. ** Treatment of samples ** - Taking bananas as an example, the crushing method could be used. The banana was placed in a sealed bag and mashed to destroy the cell wall. You can also weigh 10g of tender plant tissue and cut it into a mortar. Add 10ml of pre-cooled grinding buffer and add about 0.1 g of SSS, and grind it into a paste on an ice bath. 2. ** Add extract ** - For the mashed banana, add 10ml of extract. The extract is a mixture of a surfacing agent and salt. The surfacing agent can clean the cell membrane, and the salt can fully dissolve the DNA into the solution. - For the young plant tissues that were ground into paste, add an equal volume of a mixture of chloride-isopentool (a mixture of 24ml of chloride-isopentool and 1ml of isopentool), add a stopper, shake it vigorously for 30 seconds, transfer it to a centrifugal tube, and let it stand for a moment to remove the tissue protein. Then, spin it at 4000 revolutions per minute for 5 minutes and divide it into three layers. Carefully suck the upper layer of the clear liquid into a graduated test tube, and discard the cell debris, denature protein in the middle layer, and the chloride-like in the lower layer. 3. ** Follow-up treatment ** - For example, place the test tube in a water bath at 72 ° C for 3 minutes (no more than 4 minutes) to inactivate the tissue's DNA. Then quickly take out the test tube, place it in an ice-water bath to cool it to room temperature, and add a 5-mole/L solution (extract: solution = 4:1(V/V)) to make the final concentration of the solution 1-mole/L. - Then, an equal volume of the chloride-Isopentyl alcohol mixture was added into the large test tube again, and the mixture was shaken for 1 minute. After standing still, the mixture was spun at room temperature for 5 minutes at 4000 revolutions per minute, and the supernate was taken and placed into a small beaker. - Use a burette to suck 95% pre-cooled alcohol and slowly add it to the surface of the beaker's supernate until the volume of alcohol is twice that of the supernate. Gently stir it with a glass rod. At this time, the nuclear acid quickly wraps around the glass rod in the form of a fiber. Then, add about 0.5ml of 10ssc (weigh 87.66g of NaCl2 and 44.12g of trisodic citrates, dissolve them separately, and make them 1000ml together) to make the final concentration of 1ssc. - The crude DNA product could be obtained by repeating the steps of alcohol and 10ssc treatment. After that, the processed RNase-like reagent solution (25-milligram/milliliter of the reagent solution was prepared with 0.14-milligram/milliliter of NaCl-like reagent solution, 1-milligram/milliliter of HCl-like reagent solution was added, and the reagent was treated in a water bath at 80 ° C for 5 minutes before use) was added, so that the final concentration of the reagent was 50 - 70? g/milliliter. The reagent was then incubated in a water bath at 37 ° C for 30 minutes to remove the RNase-like reagent. - Add an equal volume of a mixture of chlouroform-isopentanol, shake it in a triangular flask for 1 minute, remove the residual protein and the added RNase-protein, and then incubate it at 4000pm for 5 minutes at room temperature to collect the upper layer of the water solution. After that, the purified DNA solution was obtained by the steps of alcohol and 10ssc. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

Shi Hao's supreme being bone was taken away from him in the national comic 'Perfect World'. Shi Hao was the son of the eleventh master of the Martial Imperial Manor, Shi Ziling. He possessed a rare and precious supreme being bone. However, after his brother Shi Yi discovered the supreme being bone on Shi Hao's body, he told his mother about it. While Shi Hao's parents were away, Shi Yi's mother went crazy and took away Shi Hao's supreme being bone, then transplanted it into Shi Yi's body. This caused Shi Yi to become a supreme youth with dual pupils and supreme being bone. Not having the supreme being bone was a huge loss for Shi Hao. Not only was it a physical and mental torture, but it also had a huge impact on his future. He went from his youth state to an extremely weak infant state that could die at any moment. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The titanium black bio-film was a kind of organic composite paint with very good blackness. It was also a new energy functional material with pure blackness and strong activity. It was also called black titanium metal dioxide. It was a non-stick layer material of ceramic crystal. The surface used a new and upgraded ceramic crystal surface treatment process. It was processed into super-hard ceramic crystals with ceramic molecules as the basic material. It relied on the far-infrared function to allow food to be heated more evenly. It could control the local temperature to reduce oil smoke and retain food nutrition, but the price was higher. Iron or steel spatula and steel wire balls cannot be used for cleaning, as they are easy to damage the coating. Teflon was another name for PVP. It was a sheet made of PVP dispersed resin with an organic catalyst as an auxiliary agent. It was molded by molding, molding, or hydraulic molding, and then turned or rolled. It was divided into two types: molded sheet and turned sheet. It has excellent high and low temperature resistance, chemical stability, electrical insulation performance, non-stickiness, weather resistance, flame retardance, good self-smoothness and other characteristics. It is widely used in various fields such as chemical industry, oil, textile, electronic and electrical, medical, mechanical, aerospace, etc. It can be used as a liner, seal, and grease material in various corrosive media at a temperature of-180 ° C to +250 ° C. It is non-toxic and has physiological inertia. However, high-temperature cracking produces highly toxic by-products. When using non-stick cooking utensils, it should be lower than 260 ° C and pay attention to safety protection to prevent contact with open flames. There were differences between the two in terms of composition, function, application scenarios, and precautions. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The following are some novels that have traveled across the continent and ended, but it is uncertain if they contain magic and combat qi elements: - "Wandering Knight's Opening: I Have a Simple Data Panel": The protagonist travels through the feudal society of the Middle Ages in another world. He starts from the second son of the knight family and walks on the road to the empire with a simple data panel. The content involves training soldiers, forging weapons, building castles, and other plots. - [The Ashen Sword: The protagonist transmigrated to a different world that was exactly the same as the game world. As he used to be a professional expert and knew that there was a chance to return to the real world, he pulled a mercenary group to help him push the Boss back. The eight girls in the mercenary group all fell in love with him as they got along with each other.] - "This Number Is Poisonous": A novel from another world. The protagonist was an NPC template when he transmigrated to the game world. As soon as he transmigrated, he was caught by the little witch and wanted to be used as a cauldron. - "Please Have Respect, Player": This is the fourth natural disaster of farming in the game. It summons players to work for you in another world, creating a virtual game. It has a system and was created by an old author. The protagonist has a harem and has a brain. The world in the book can be self-consistent. - "I'm Really Not Against Mages": The protagonist transmigrated into a game with a knd-like worldview. He has a special class template of "Heroic Concealment". He can permanently increase one of his attributes/resistance/abilities by killing specific monsters. - "Pretend to be a Boss": The story is set after a terrible disaster. Humans are forced to move into countless pyramids that have appeared on Earth at some point in time. According to the rules of the pyramids, a solid class society is formed to continue. Only those who have the talent to enter the Kuangqu are needed by the pyramids. - "We Monsters Don't Want to Die" was similar to the setting of a Super Divine Mechanic who could wear NPCs. It was a game where the gods pulled a large number of top players into the world to search for treasures. - "Time Freeze 499 Years": The core of the game "Weird" was the evil spirits and monsters. The protagonist had a maxed out game account. One day, he discovered that time in the real world had stopped. Some existence began to use "Weird" as a template to transform the world. The protagonist was transformed into the lowest level of a wandering ghost, and time was stopped for 499 years. - "Don't Run, Demon King Warrior": An unusual opening of the game, similar to the opening setting of the game life. The protagonist and the goddess beat the goddess half to death in the game, and then the goddess invited him to participate in the Demon King Warrior RPG game designed by her. He was also forced to enter the hell difficulty (civilian opening). - "Old Ancestor, Please Come Out of the Mountain" was a fantasy novel. The plot included the development of the human race and other content. - [My All-purpose Tinder: Fantasy novel, 1.38 million words.] - "Seize the Three Thousand Worlds at the Beginning!" It was a fantasy novel with 4.81 million words. - [My Martial Soul is a Coffin]: A fantasy novel with 1.13 million words. - "I Have a Mythical Tree" was a fantasy novel with a unique setting in the development of the human race. - "Splashing Knife": A fantasy immortal cultivation novel with a Ming Dynasty background. The main character travels through a different world, slaying demons while exploring the world. - "Mixed in the Doomsday, Becoming Immortal Alone": A sci-fi + Doomsday + Immortal Cultivation type of novel. After the protagonist fails to transcend the tribulation, he transmigrated to another world and realized his Dao heart, determined to transcend the tribulation and become immortal again. - "Desperate Night": A strange immortal cultivation novel that contains elements of doomsday, point-adding style, and doomsday fortress nurturing style. - "Lightning Technique Mastery, you're telling me it's in the Strange World?" No more detailed information was found. - "I am an Immortal": A Xianxia novel. The protagonist fell into the space station in a space hibernation capsule and transmigrated to ancient times. The artificial intelligence that collected weather activities was still operating. It could also broadcast weather forecast in ancient times. The novel "Yan Xiaoqi's Journey to the Other World" is equally exciting. Everyone is welcome to click and read it!

In " Smiling Proud in China," the protagonist, Ye Fan, created a business legend in England called Yanhuang Group. This was a modern urban novel. The protagonist, Ye Fan, was an orphan. He was talented and intelligent. At the age of two, he was adopted by a hidden expert. He studied medicine and martial arts. He was proficient in music, chess, calligraphy, and painting. Eight years later, he founded the Yanhuang Group in England. After returning to China, he faced the temptation of love, power, and secular prejudice. This novel was a typical cool novel. The protagonist cheated all the way, surrounded by countless beautiful women who fell in love with him at first sight. His combat strength was very strong, and he could beat all the tall, rich, and handsome men. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

In the reference materials, the connection between "The Burning of Peaches" and Nishuihan was only reflected in the description of "The Burning of Peaches" in the recommendation of Nishuihan's Suwen. It might imply that it was related to medicine (Suwen was an auxiliary treatment profession). Other than that, there was no other information that clearly connected the two. While waiting for the TV series, he could also read the exciting content related to this site!

In " After the Ambitious Hero Marries into the Family," the female lead transmigrated and became the legitimate daughter of the Anyang City Lord, but the female lead's name was not mentioned. In " Metaphysical Princess Consort Divination, Abstinence, and the King's Addiction," the female lead transmigrated and became the sixth miss of the Anyang Marquis's Mansion, Nan Li, who had been lost for many years. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

Chen Feiyu's mansion was a courtyard house located in an alley in Beijing. This was where his father, Chen Kaige, grew up. There were two gingko trees with red lanterns hanging in the courtyard. The house was a one-and-a-half-floor structure with half a basement below. The room was mainly orange-yellow in color, and there were exquisite wooden chairs carved with flowers. It was full of the atmosphere of old Beijing. In addition to the front yard, there was a side yard and backyard around the house. There were stairs in the house, and the indoor space was spacious. It was estimated to be more than 1,000 square meters, worth 440 million dollars. While waiting for the TV series, he could also read the exciting content related to this site!

Here are some examples of ordinary people's contributions: - During the epidemic period, community workers not only completed the anti-epidemic task in their own community, but also took the initiative to support other communities by doing random DNA tests for patients. They often woke up early and went to bed late. There were community workers who coordinated with the police station and relevant departments during the lunch break to help the children of divorced families solve their difficulties. They gave up their small families for everyone and interpreted greatness in ordinary positions. - Li Youfu of the Agriculture and Animal Husbandry Technology Service Station in Dhaka Township, Banma County, Guoluo Prefecture, Qinghai Province, had been working for 12 years. He had supported four poor college students to complete their studies with a meager income (one of them was an orphan). In 2020, he donated 1000 yuan to the frontline medical staff. He had paid a large amount of party membership fees of 41000 yuan since he joined the party for 13 years. He went deep into the village to help poor families many times, and also funded poor students to complete their studies, practicing the dedication of the Party members with actions. - Farmer Wu Hongpu has been silently contributing to national security for 37 years. During his military career, he successfully commanded his troops to shoot down the U - 2 reconnaissance plane that violated our country's airspace and made great achievements. However, after retiring, he concealed his identity to keep secrets and returned to his hometown to be an ordinary farmer. He silently contributed without asking for anything in return. It was only 37 years later that his hero identity was revealed. - Zhu Youfang, a female teacher with a broken body and strong will, did not give up her dream of becoming a teacher even though she failed her middle school entrance examination. She first taught in a private college, then was admitted by Daye Normal School through hard work. After graduation, she became a public teacher. Like her father, she devoted her energy to her students, worked hard to inherit her father's will, and even under difficult conditions, she still stuck to her educational post and dedicated herself. The Extraordinary Ordinary Life novel is equally exciting. Everyone is welcome to click and read it!

This statement was too absolute. Although Zhang Ruonan was an actress with good looks, a certain reputation in the entertainment industry, and good acting skills, she might be liked by many men. However, different boys had different aesthetic standards, hobbies, and ideas about choosing a partner. Some boys might pay more attention to other types of women, such as those who have outstanding achievements in specific fields, have unique personalities, or perform well in public welfare, but not necessarily like Zhang Ruonan. While waiting for the TV series, he could also read the exciting content related to this site!