According to Arrhenius theory, what makes a substance an acid?

It releases H⁺ ions when dissolved in water.

It accepts a proton from another substance.

It produces OH⁻ ions in water.

It donates a pair of electrons.

How does the Brønsted–Lowry theory define an acid?

A substance that produces OH⁻ in water.

What is the primary focus of the Lewis acid-base theory?

The transfer of electron pairs.

The presence of hydroxide ions.

The production of salt and water.

The transfer of protons (H⁺).

First to the Flag | Quizalize

The Philippine Flag Our country is officially identified through our flag. The Philippine flag has three colors: white, blue, and red. White signifies purity; blue means hope and peace; and red denotes bravery. The three stars symbolize the three big groups of islands of our country-the Luzon, Visayas, and Mindanao. The eight rays of the sun signify the eight provinces that first revolted against the Spaniards. These are Bulacan, Pampanga, Tarlac, Nueva Ecija, Laguna, Batangas, Manila, and Cavite. We respect our flag to show that we respect our country. We should not treat it like an ordinary cloth because it symbolizes our country. An old flag should be burned and not be used as a rag. Title: National Hero Body text: Dr. Jose Rizal was from a middle-class family from Calamba, Laguna. He is regarded as a genius who fought the Spaniards through his writings, especially the novels "Noli Me Tangere" and "El Filibusterismo." The two novels exposed the anomalies and wrongdoings of the Spanish government against the Filipino people. He wrote the poem "Mi Ultimo Adios" the eve before his execution in Bagumbayan (now known as Rizal Park). National Fruit A mango is sour when it is green, but very sweet when it is ripe. This heart-shaped fruit symbolizes the kindness of the Filipinos. It has a big tree that bears fruits abundantly during summer. National Animal A carabao is a model of hard work and industry. It is the best companion of farmers in the field. It is black and looks like a tamaraw. A carabao is a very strong animal in terms of work. It symbolizes the Filipinos as hardworking and patient. National Bird The Philippine eagle, also known as haribon, stands over 5 feet (1.6 m) tall. It has a large, sharp, and aggressive beak and has powerful talons. Philippine eagles are excellent hunters, and live in tropical rainforests. These eagles lay just one or two eggs each year. National Tree The narra is a hardy tree that grows big and is found mainly in the Bicol Region, Mindanao, and Cagayan Valley forests. Most of the desks and tables in schools are made of narra. It signifies the strong personality of Filipinos in facing trials in life. National Flower The sampaguita has white, star-shaped petals with a sweet fragrance. It is made into garlands, which are given to visitors and special persons on occasions. It signifies purity and among Filipino women. National Fish Bangus or milkfish is our national fish. It grows in ponds or freshwater and tastes delicious. Its white, shiny scales signify our beautiful country. National Dance Cariñosa is a dance of love using a handkerchief and a fan. It symbolizes the true love expressed by Filipinos. National House A nipa hut is a small but beautiful house made from bamboo and sawali or cogon leaves. Filipinos used this kind of house during the olden times. At present, there are still people using this as a dwelling place, but most of the time, they use it as a rest place or cottage. National Costume Barong Tagalog is the national costume for Filipino men. It is made from pineapple fiber or other native materials. Filipinos wear this on special occasions such as formal events or weddings. Baro at Saya is the national dress for Filipino women. Most of them are made from jusi or pineapple fiber and other native materials. This dress shows the gracefulness of Filipino women. National Leaf Our national leaf is a palm tree. It is wide and narrow like an open fan. Farmers use this to protect their crops from the harsh sunlight and rain. It grows like a tree with thorns in its body. National Language Our national language is Filipino, which is based in Tagalog. Through the efforts of former President Manuel L. Quezon (known as the "Father of the National Language"), Filipino was widely disseminated and is now used in all parts of the country. With this, Filipinos in different cultures and native tongues can still communicate with each other. National Food Lechon (litson) is an important dish served at many occasions, especially on fiestas. Lechon is a suckling pig, slowly roasted over live coals to make it crispy and tasty. National Footwear Bakya is the national footwear of the Philippines. It was most popular from the 1950s to the 1970s before the introduction of rubber slippers. There are several colors and designs of bakya that suit the taste of most Filipinos. Valuing Our National Symbols Symbols represent a country and its people. We have to respect and value these symbols because they tell something about our country and of who we are as Filipinos. Here are some ways of valuing our national symbols: When singing the national anthem, stand straight and place your right hand on your left chest. Remove your cap or close your umbrella. Ask the people walking to stop while the flag is being raised. Tell other children to stop chatting while singing the national anthem. Most importantly, sing the national anthem wholeheartedly. Retirement of a Flag: A worn-out flag should be disposed of respectfully. It should be burned in a dignified ceremony, not thrown away or used for other purposes. Help in saving and conserving our forests. They serve as habitat of our national bird and other animals. You may also help organizations that promote reforestation, clean and green programs, and tree planting activities. Do not pick flowers when visiting parks. Instead, help in keeping these places clean and beautiful. Avoid throwing thrash in their surroundings. Patronize products that are made here in our country and made by Filipinos. Tell your family and friends to buy products of the Philippines especially those of which are our national symbol. Aside from patronizing our own products, let us use and love our national language. It is good to learn foreign languages, but do not forget to use our own language correctly and proudly.

THE BATTLE OF THE PHILIPPINE SEA Occured in the Philippine Sea and Marinas The battle engaged the bulk of thepagan American forces, and prevented the Japanese from reinforcing, their fleet in the •Marianas. •A month after, the Japanese LOST THEIR 4 best aircraft carriers in the Battle of Midway, an island northwest of Pearl "Harbor. 1. The Batle of the Philipine Sea lasted just one day June 19- June 20 1944 3. is also called the "Marianas Turkey Shoot” The Battle of the Coral Sea The Coral Sea is Between New Guinea and Australia The Japanese Were Trying to Attack Australia! The U.S. Navy and the Japanese Navy Fought! Nobody Won! U.S. Was Able to STOP the Attack on Australia! (Victory!) The American fleet defeated the Japanese. American planes bombarded Japanese installation in Manila from the air. Air strikes were also carried out in the Visayas. Battle of Okinawa: Battle Details The attack on Okinawa took heavy toll on both sides of the fighting... The Americans lost 7,373 men killed and 32,056 wounded on land. At sea, the Americans lost 5,000 killed and 4,600 wounded. The Japanese lost 107,000 killed and 7,400 men taken prisoner. The Japanese may have lost another 20,000 dead as a result of American tactics whereby Japanese troops were incinerated where they fought. The Americans also lost 36 ships. 368 ships were also damaged. 763 aircraft were destroyed. The Japanese lost 16 ships sunk and over 4,000 aircraft were lost. battle facts -the japanese launched fierce kamikaze attacks l-arge amouunts of civillian deaths -japanese soldiers using civilians as human shields Americans ended with more triumphs in the battles like in: General MacArthur and the Allies next turned to the Island of Iwo Jima The island was critical to the Allies as a base for an attack on Japan It was called the most heavily defended spot on earth Allied and Japanese forces suffered heavy casualties IWO JIMA American soldiers plant the flag ol the Island of Iwo Jima after their victory Battle of Leyte Gulf "Second Battle of the Philippine Sea". Time: October 23 - 26, 1944 during WW. Location: Leyte Gulf in Philippines (East coast), Philippine islands of Leyte, Samar, and Luzon. Largest naval battle in WWII. Leyte was secured and was liberated from the hands of the Japanese Americans decided to launch their attack in Leyte since the weak side of the Japanese fleet was in Visayas. Heavy bombing at the Leyte beaches cleared the way for the landing in Palo, Leyte. Leading the American troops were General Douglas MacArthur and President Osmeña, who took over after the death of President Quezon in Saranak Lake in New York. the battle for the liberation of manila The commonwealth government capital was transferred from tacloban to Manila. Manila once again became the seat of the national leadership. ON july 4, 1945, general macarthur announced the total liberation of the Philippines • The Commonwealth government capital was transferred from Tacloban to Manila. Manila once again became the seat of the national leadership. On July 4, 1945, General MacArthur announced the total liberation of the Philippines. Americans surprised the Japanese with the landing of troops in Lingayen Gulf in Pangasinan. • The Filipino guerillas had already cleared the area and neutralized many of the Japanese forces. The first target was the UST, which was used by the Japanese as a camp for civilian prisoners of war, and they were able to free them. • More than 1000 POWs from Bataan and Corregidor were also freed from the Bilibid Prisons. • The battle of Manila was recorded as the fiercest urban fighting in the entire Pacific War. WATERLOO DAILY COURIER-NEWSPAPER “PEACE! WAR ENDS; JAPANESE ACCEPT ALLIED TERMS. ON EMPEROR" On August 6, due to persistent refusal of Japan to yield, another atomic bomb was dropped in the shipbuilding city of Nagasaki. On August 15, V-J Day (Victory in Japan), Emperor Hirohito finally admitted defeat and on September 3, 1945 the document of surrender was signed on board of the U.S. battleship Missouri in Tokyo Bay. With the liberation of the Philippines, the Americar troops moved on to finally end the war in Asia. The Japanese cities of Tokyo, Osaka, Nagoya and Kure were bombed. In July 26, the allies demanded surrender but the Japanese continued to hold on to their belief that surrender is a dishonor. Atomic bomb was dropped on the populous city of Hiroshima, 60% of the city was destroyed. It was estimated that there were more than 80 000 people died on the spot and more than 37 000 suffered severe injuries. Today, the HIROSHIMA SHRINE serves as a reminder of th horrors of war and the need to preserve PEACE in the world. THE POSTWAR PHILIPPINE COMMONWEALTH-• Philippine Commonwealth resumed. Osmeña was confronted with a war - ravaged country with no financial resources for PROBLEMS • Poverty • Destruction of Properties • Unemployment • Price Increase • Hoarding • Graft and Corruption HINDRANCES -Rehabilitation of INDUSTRIES COULD NOT BE DONE BECAUSE OF LACK OF FUND -RAILWAYS WERE DESTROYED THAT LED TO SLOW PRODUCTION AND TRANSPORTATION SOLUTION -PCAU (Philippine Civil Affairs Unit) was established by MacArthur to provide emergency relief in areas liberated by the Americans. - It organized food distribution centers. CHALLENGES TO INDEPENDENCE • On April 30, 1946, the Philippine the US President. BIASED AGREEMENTS: Rehabilitation or the Tydings Act of 1946, passed by the US Congress, was approved by Commission • This Act created the US Philippine War Damage The Act also provided for the transfer of $100,000,000 surplus property of the United States to the Philippines. The Philippine Armed Forces received large quantities of valuable military equipment and supplies. BIASED AGREEMENTS: • The United States Congress offered $800 million for post World War Il rebuilding funds if the Bell Trade Act was ratified by the Philippine Congress Parity rights granting U.S. citizens and corporations rights to Philippine natural resources equal to (in parity with) those of Philippine citizens The Philippines used to celebrate its Independence Day on July 4, and not June 12, by virtue of the Truman Proclamation in 1946. In the early 1960s, however, the Philippine Historical Association lobbied to bring back June 12 as our Independence Day. In 1962, President Diosdado Macapagal issued a proclamation to make the change official. DECLARATION OF PHILIPPINE INDEPENDENCE • On July 4, 1946, the Americans granted independence to the Philippines.

When it was his turn to speak, Adam Malik, Presidium Minister for Political Affairs and Minister for Foreign Affairs of Indonesia, recalled that about a year before, in Bangkok, at the conclusion of the peace talks between Indonesia and Malaysia, he had explored the idea of an organization such as ASEAN with his Malaysian and Thai counterparts. One of the “angry young men” in his country’s struggle for independence two decades earlier, Adam Malik was then 50 years old and one of a Presidium of five led by then General Soeharto that was steering Indonesia from the verge of economic and political chaos. He was the Presidium’s point man in Indonesia’s efforts to mend fences with its neighbors in the wake of an unfortunate policy of confrontation. During the past year, he said, the Ministers had all worked together toward the realization of the ASEAN idea, “making haste slowly, in order to build a new association for regional cooperation.” Adam Malik went on to describe Indonesia’s vision of a Southeast Asia developing into “a region which can stand on its own feet, strong enough to defend itself against any negative influence from outside the region.” Such a vision, he stressed, was not wishful thinking, if the countries of the region effectively cooperated with each other, considering their combined natural resources and manpower. He referred to differences of outlook among the member countries, but those differences, he said, would be overcome through a maximum of goodwill and understanding, faith and realism. Hard work, patience and perseverance, he added, would also be necessary. The countries of Southeast Asia should also be willing to take responsibility for whatever happens to them, according to Tun Abdul Razak, the Deputy Prime Minister of Malaysia, who spoke next. In his speech, he conjured a vision of an ASEAN that would include all the countries of Southeast Asia. Tun Abdul Razak was then concurrently his country’s Minister of Defence and Minister of National Development. It was a time when national survival was the overriding thrust of Malaysia’s relations with other nations and so as Minister of Defence, he was in charge of his country’s foreign affairs. He stressed that the countries of the region should recognize that unless they assumed their common responsibility to shape their own destiny and to prevent external intervention and interference, Southeast Asia would remain fraught with danger and tension. And unless they took decisive and collective action to prevent the eruption of intra-regional conflicts, the nations of Southeast Asia would remain susceptible to manipulation, one against another. “We the nations and peoples of Southeast Asia,” Tun Abdul Razak said, “must get together and form by ourselves a new perspective and a new framework for our region. It is important that individually and jointly we should create a deep awareness that we cannot survive for long as independent but isolated peoples unless we also think and act together and unless we prove by deeds that we belong to a family of Southeast Asian nations bound together by ties of friendship and goodwill and imbued with our own ideals and aspirations and determined to shape our own destiny”. He added that, “with the establishment of ASEAN, we have taken a firm and a bold step on that road”. For his part, S. Rajaratnam, a former Minister of Culture of multi-cultural Singapore who, at that time, served as its first Foreign Minister, noted that two decades of nationalist fervor had not fulfilled the expectations of the people of Southeast Asia for better living standards. If ASEAN would succeed, he said, then its members would have to marry national thinking with regional thinking. “We must now think at two levels,” Rajaratnam said. “We must think not only of our national interests but posit them against regional interests: that is a new way of thinking about our problems. And these are two different things and sometimes they can conflict. Secondly, we must also accept the fact, if we are really serious about it, that regional existence means painful adjustments to those practices and thinking in our respective countries. We must make these painful and difficult adjustments. If we are not going to do that, then regionalism remains a utopia.” S. Rajaratnam expressed the fear, however, that ASEAN would be misunderstood. “We are not against anything”, he said, “not against anybody”. And here he used a term that would have an ominous ring even today: balkanization. In Southeast Asia, as in Europe and any part of the world, he said, outside powers had a vested interest in the balkanization of the region. “We want to ensure,” he said, “a stable Southeast Asia, not a balkanized Southeast Asia. And those countries who are interested, genuinely interested, in the stability of Southeast Asia, the prosperity of Southeast Asia, and better economic and social conditions, will welcome small countries getting together to pool their collective resources and their collective wisdom to contribute to the peace of the world.” The goal of ASEAN, then, is to create, not to destroy. This, the Foreign Minister of Thailand, Thanat Khoman, stressed when it was his turn to speak. At a time when the Vietnam conflict was raging and American forces seemed forever entrenched in Indochina, he had foreseen their eventual withdrawal from the area and had accordingly applied himself to adjusting Thailand’s foreign policy to a reality that would only become apparent more than half a decade later. He must have had that in mind when, on that occasion, he said that the countries of Southeast Asia had no choice but to adjust to the exigencies of the time, to move toward closer cooperation and even integration. Elaborating on ASEAN objectives, he spoke of “building a new society that will be responsive to the needs of our time and efficiently equipped to bring about, for the enjoyment and the material as well as spiritual advancement of our peoples, conditions of stability and progress. Particularly what millions of men and women in our part of the world want is to erase the old and obsolete concept of domination and subjection of the past and replace it with the new spirit of give and take, of equality and partnership. More than anything else, they want to be master of their own house and to enjoy the inherent right to decide their own destiny …” While the nations of Southeast Asia prevent attempts to deprive them of their freedom and sovereignty, he said, they must first free themselves from the material impediments of ignorance, disease and hunger. Each of these nations cannot accomplish that alone, but by joining together and cooperating with those who have the same aspirations, these objectives become easier to attain. Then Thanat Khoman concluded: “What we have decided today is only a small beginning of what we hope will be a long and continuous sequence of accomplishments of which we ourselves, those who will join us later and the generations to come, can be proud. Let it be for Southeast Asia, a potentially rich region, rich in history, in spiritual as well as material resources and indeed for the whole ancient continent of Asia, the light of happiness and well-being that will shine over the uncounted millions of our struggling peoples.” The Foreign Minister of Thailand closed the inaugural session of the Association of Southeast Asian Nations by presenting each of his colleagues with a memento. Inscribed on the memento presented to the Foreign Minister of Indonesia, was the citation, “In recognition of services rendered by His Excellency Adam Malik to the ASEAN organization, the name of which was suggested by him.” And that was how ASEAN was conceived, given a name, and born. It had been barely 14 months since Thanat Khoman brought up the ASEAN idea in his conversations with his Malaysian and Indonesian colleagues. In about three more weeks, Indonesia would fully restore diplomatic relations with Malaysia, and soon after that with Singapore. That was by no means the end to intra-ASEAN disputes, for soon the Philippines and Malaysia would have a falling out on the issue of sovereignty over Sabah. Many disputes between ASEAN countries persist to this day. But all Member Countries are deeply committed to resolving their differences through peaceful means and in the spirit of mutual accommodation. Every dispute would have its proper season but it would not be allowed to get in the way of the task at hand. And at that time, the essential task was to lay the framework of regional dialogue and cooperation. The two-page Bangkok Declaration not only contains the rationale for the establishment of ASEAN and its specific objectives. It represents the organization’s modus operandi of building on small steps, voluntary, and informal arrangements towards more binding and institutionalized agreements. All the founding member states and the newer members have stood fast to the spirit of the Bangkok Declaration. Over the years, ASEAN has progressively entered into several formal and legally-binding instruments, such as the 1976 Treaty of Amity and Cooperation in Southeast Asia and the 1995 Treaty on the Southeast Asia Nuclear Weapon-Free Zone. Against the backdrop of conflict in the then Indochina, the Founding Fathers had the foresight of building a community of and for all Southeast Asian states. Thus the Bangkok Declaration promulgated that “the Association is open for participation to all States in the Southeast Asian region subscribing to the aforementioned aims, principles and purposes.” ASEAN’s inclusive outlook has paved the way for community-building not only in Southeast Asia, but also in the broader Asia Pacific region where several other inter-governmental organizations now co-exist. The original ASEAN logo presented five brown sheaves of rice stalks, one for each founding member. Beneath the sheaves is the legend “ASEAN” in blue. These are set on a field of yellow encircled by a blue border. Brown stands for strength and stability, yellow for prosperity and blue for the spirit of cordiality in which ASEAN affairs are conducted. When ASEAN celebrated its 30th Anniversary in 1997, the sheaves on the logo had increased to ten – representing all ten countries of Southeast Asia and reflecting the colors of the flags of all of them. In a very real sense, ASEAN and Southeast Asia would then be one and the same, just as the Founding Fathers had envisioned. This article is based on the first chapter of ASEAN at 30, a publication of the Association of Southeast Asian Nations in commemoration of its 30th Anniversary on 8 August 1997, written by Jamil Maidan Flores and Jun Abad.

Bacterial Cell One of the very first organisms to evolve on earth was probably a unicellular organism, like modern bacteria. Ever since then, life has evolved into a multitude of life forms over many millennia. However, we can still trace our ancestry back to this single-celled organism. Bacteria Definition “Bacteria are unicellular organisms belonging to the prokaryotic group where the organisms lack a few organelles and a true nucleus”. Internal Structures • Cytoplasm: A gel-like substance that fills the cell, containing water, enzymes, nutrients, and waste, where metabolic activities occur. • Nucleoid: A region within the cytoplasm that houses the bacterial chromosome, a single, continuous circle of DNA. • Ribosomes: Responsible for synthesizing proteins within the cell. • Plasmids: Small, circular, extra-chromosomal DNA molecules that can provide advantageous traits, such as antibiotic resistance. • Mesosomes: (Optional, less prominent in some views) Folds in the plasma membrane that are believed to be involved in cell division and respiration. Outer Structures & Layers • Cell Wall: A rigid outer layer composed of peptidoglycan that provides structural support, maintains cell shape, and protects against osmotic lysis. Capsule: (Optional) A sticky outer layer of polysaccharide that can help the bacteria adhere to surfaces, protect against phagocytosis by the immune system, and serve as a food reserve. • Plasma Membrane: A selectively permeable barrier that regulates the passage of nutrients and waste products into and out of the cell. Appendages • Flagella: Long, whip-like structures that provide motility, allowing the bacterium to move through its environment. • Pili (and Fimbriae): Hair-like protein appendages. Pili are longer and involved in bacterial conjugation (transfer of genetic material), while the shorter, more numerous fimbriae primarily function in attachment to host cells or surfaces.

Here’s your **edited version** of the activity, now focused on **Shirley Jackson’s *“The Lottery”*** and **past and present participles**, while keeping the fun “Great Grammar Magician” game theme: --- ### 🎩 THE GREAT GRAMMAR MAGICIAN: “THE LOTTERY SPELL!” 🍀 It seems like you already know how **past and present participles** can transform simple verbs into more descriptive and expressive words. Now, it’s time to show your magical grammar powers and help the Great Grammar Magician complete her enchanting performance inspired by *“The Lottery”* by Shirley Jackson! --- ### 🌼 **THE LOTTERY SPELL!** **Directions:** The class will be divided into two groups, and each group will work together to help the Great Grammar Magician finish her magical act! Each group will receive **three magic flags** that can be used as advantages during the game: 🟩 **Green Flag** – Use for a clue about the question. 🟨 **Yellow Flag** – Use to look at the question first and decide whether to answer it or choose another one. 🟦 **Blue Flag** – Use to get another chance to answer the same question. The goal is to earn the **highest points** as a group. The first representative to raise their hand gets to choose a question to answer. There will be **six questions**, representing the **six stones** drawn during the “lottery.” Each stone contains a **Magic Spell Card** with a question your group must answer correctly to earn a point. --- ### 🪄 **MAGIC SPELL QUESTIONS** **1. Remembering** **Question:** Who is the author of *“The Lottery”?* **Expected Answer:** Shirley Jackson. --- **2. Understanding** **Question:** What is *“The Lottery”* mainly about? **Expected Answer:** It’s about a small town that follows a cruel tradition of holding a lottery where one person is chosen to be sacrificed. --- **3. Applying** **Question:** Identify a **past or present participle** used in *“The Lottery.”* Explain its function in the sentence. **Expected Answer:** Example: *“The children assembled first, of course.”* — “assembled” is a **past participle** used to describe what the children did before the lottery began. --- **4. Analyzing** **Question:** How does Shirley Jackson use participles to create suspense or describe actions in the story? **Expected Answer:** Participles like “gathered,” “watching,” or “whispered” make the actions more vivid and help build tension in the story. --- **5. Evaluating** **Question:** Do you think the townspeople’s calm behavior (described with participles like “smiling,” “talking,” “laughing”) makes the story more shocking? Why or why not? **Expected Answer:** (Open-ended) Yes, because the ordinary actions make the violent ending more disturbing / No, because it just shows how normal the ritual is to them. --- **6. Creating** **Question:** Write your own short two-line description using **past or present participles** to show tension or fear in a situation like the one in *“The Lottery.”* **Expected Answer:** (Open-ended) Example: *Shaking hands held the paper tight.* *The crowd waited, holding their breath.* --- ### 🪶 **Tie-Breaker Question** **Question:** If you were in *“The Lottery,”* what would you be doing as the black box was brought out? Use at least one participle in your answer. **Expected Answer:** (Open-ended; checks creativity and grammar) Example: *Standing in silence, I would watch the slips being drawn, my heart pounding.* --- Would you like me to make this version **visually formatted for a classroom printout** (e.g., with bold headers, emojis, and clear section boxes)?

Maria's Family Celebration It is Mexican Independence Day! Maria and Luis are getting ready for a big party. "We can decorate the house," says Maria. "Let's paint a picture of our family." "Mama was born first. She is the oldest," says Maria. "Papa was born second," Maria says. "He is one year younger." "Next is Emily," says Maria. "She is Mama and Papa's first child." "After Emily, you were born," says Luis. "That's right!" says Maria. "I am Mama and Papa's second child." "What about me?" asks Luis. "You were the last to be born," says Maria. "You are the youngest." "There!" says Maria. "Our family picture is done!" "Green, white, and red are the colors of the Mexican flag," says Maria. Maria and Luis blow up five green balloons. They blow up five white balloons and five red balloons, too. "I'm out of breath!" says Luis. "Let's see," says Maria. "We painted a picture first. We blew up balloons second. The third thing we can do is fill the piñata." Maria gets the striped fish piñata from the shelf. Maria and Luis stuff the piñata with candy. When Luis thinks Maria isn't looking, he pops a piece of candy into his mouth. Maria gives him a hug. "You are silly," she says. Papa hangs the piñata. "We need a blindfold," says Maria. "We need a stick to break the piñata, toо." Abuela finds a red-checked scarf for Maria and a long stick for Luis. "The piñata is ready!" says Maria. "The fourth thing to do is practice dancing, Luis!" Maria and Luis dress in their party clothes. Then, they dance and spin. Soon, the house fills up with food, family, and music. There are six cousins, two aunts, three uncles, and three grandparents. There is Papa, Mama, Emily, Maria, and Luis, too. "There is one last thing we can do," Maria says. "And it's the most fun!" "What is it?" asks Luis. "CELEBRATE!" says Maria.

Carlos's Family Celebration It's Mexican Independence Day! Carlos and Selena are getting ready for a big party. "We can decorate the house," says Carlos. "Let's paint a picture of our family." "Mama was born first. She is the oldest," says Carlos. "Papa was born second," Carlos says. "He is one year younger." "Next is Mateo," says Carlos. "He is Mama and Papa's first child." "After Mateo, you were born," says Selena. "That's right!" says Carlos. I am Mama and Papa's second child." "What about me?" asks Selena. "You were the last to be born," says Carlos. "You are the youngest." "There!" says Carlos. "Our family picture is done!" "Green, white, and red are the colors of the Mexican flag," says Carlos. Carlos and Selena blow up five green balloons. They blow up five white balloons and five red balloons, too. "I'm out of breath!" says Selena. "Let's see,"says Carlos. "We painted a picture first. We blew up balloons second. The third thing we can do is fill the piñata.” Carlos gets the big star piñata from the shelf. Carlos and Selena stuff the piñata with candy. When Selena thinks Carlos isn't looking, she pops a piece of candy into her mouth. Carlos gives her a hug. "You are silly," he says. Mateo hangs the piñata in the apartment's grassy yard. "We need a blindfold," says Carlos. "And a stick to break the piñata, too." Abuela finds a red-checked scarf for Carlos and a long stick for Selena. "The piñata is ready!" says Carlos. "The fourth thing to do is practice dancing, Selena!" Carlos and Selena dress in their party clothes. Then, they dance and spin. Soon, the house fills up with food, family, and music. There are cousins, aunts, uncles, new babies, and new friends. There is Papa, Mama, Mateo, Carlos and Selena, too. "There is one last thing we can do," Carlos says. "And it's the most fun!" "What is it?" asks Selena. "CELEBRATE!" says Carlos.

Cell Size Cells differ not only in their shape but also in their size. A few types of cells are large enough to be seen by the unaided human eye. For example, the nerve cells that extend from a giraffe’s spinal cord to its foot can be 2 m (about 6 1/2 ft) long. A human egg cell is about the size of the period at the end of this sentence. Most cells, how- ever, are only 10 to 50 μm in diameter, or about 1/500 the size of the period at the end of this sentence. The size of a cell is limited by the relationship of the cell’s outer surface area to its volume, or its surface area–to-volume ratio. As a cell grows, its volume increases much faster than its surface area does, as shown in Figure 4-5. This trend is important because the materials needed by a cell (such as nutrients and oxygen) and the wastes produced by a cell (such as carbon dioxide) must pass into and out of the cell through its surface. If a cell were to become very large, the volume would increase much more than the surface area. Therefore, the surface area would not allow materials to enter or leave the cell quickly enough to meet the cell’s needs. As a result, most cells are microscopic in size. Comparing Surface Cells Materials microscope, prepared slides of plant (dicot) stem and ani- mal (human) skin, pencil, paper Procedure Examine slides by using medium magnification (100). Observe and draw the sur- face cells of the plant stem and the animal skin. Analysis How do the surface cells of each organism differ from the cells beneath the surface cells? What is the function of the surface cells? Explain how surface cells are suited to their function based on their shape. Quick Lab Small cells can exchange substances more readily than large cells because small objects have a higher surface area–to-volume ratio. FIGURE 4-5 mb06se_csfs02.qxd 5/18/07 10:54 AM Page 73 74 CHAPTER 4 BASIC PARTS OF A CELL Despite the diversity among cells, three basic features are common to all cell types. All cells have an outer boundary, an interior sub- stance, and a control region. Plasma Membrane The cell’s outer boundary, called the plasma membrane (or the cell membrane), covers a cell’s surface and acts as a barrier between the inside and the outside of a cell. All materials enter or exit through the plasma membrane. The surface of a plasma mem- brane is shown in Figure 4-6a. Cytoplasm The region of the cell that is within the plasma membrane and that includes the fluid, the cytoskeleton, and all of the organelles except the nucleus is called the cytoplasm. The part of the cytoplasm that includes molecules and small particles, such as ribosomes, but not membrane-bound organelles is the cytosol. About 20 percent of the cytosol is made up of protein. Control Center Cells carry coded information in the form of DNA for regulating their functions and reproducing themselves. The DNA in some types of cells floats freely inside the cell. Other cells have a mem- brane-bound organelle that contains a cell’s DNA. This membrane- bound structure is called the nucleus. Most of the functions of a eukaryotic cell are controlled by the cell’s nucleus. The nucleus is often the most prominent structure within a eukaryotic cell. It maintains its shape with the help of a protein skeleton called the nuclear matrix. The nucleus of a typical animal cell is shown in Figure 4-6b. Most animal cells have a cell membrane, a nucleus, and a variety of other organelles embedded in a watery substance. The surface of the cell membrane can be seen in (a). The organelles inside the cell are labeled in the diagram (b). FIGURE 4-6 (a) (b) Mitochondrion Microfilaments Lysosome Golgi apparatus Smooth ER Ribosomes Cell membrane Microtubules Rough ER Nuclear pore Nuclear envelope Nucleolus Nucleus Copyright © by Holt, Rinehart and Winston. All rights reserved. Cell wall Ribosome Cell membrane Peptidoglycan Pili Flagellum DNA CELL STRUCTURE AND FUNCTION 75 A prokaryotic cell lacks a membrane- bound nucleus and membrane-bound organelles. Most prokaryotic cells are much smaller than eukaryotic cells are. FIGURE 4-7 A white blood cell (eukaryotic) changes shape as it attacks purple- stained bacterial cells that are much smaller (prokaryotic). FIGURE 4-8 TWO BASIC TYPES OF CELLS Fossil evidence suggests that the earliest cells on Earth were simple cells similar to some present-day bacteria. As cells evolved, they differentiated into two major types: prokaryotes and eukaryotes. Prokaryotes Prokaryotes (proh-KAR-ee-OHTS) are organisms that lack a membrane- bound nucleus and membrane-bound organelles. Although prokaryotic cells lack a nucleus, their genetic information—in the form of DNA—is often concentrated in a part of the cell called the nucleoid. Figure 4-7 shows a typical prokaryotic cell. Prokaryotes are divided into two domains: Bacteria and Archaea (ahr-KEE-uh). The domain Bacteria includes organisms that are similar to the first cellular life-forms. The domain Archaea includes organisms that are thought to be more closely related to eukaryotic cells found in all other kingdoms of life. Eukaryotes Organisms made up of one or more cells that have a nucleus and membrane-bound organelles are called eukaryotes (yoo-KAR-ee-OHTS). Eukaryotic cells also have a variety of subcellular structures called organelles, well-defined, intracellular bodies that perform specific functions for the cell. Many organelles are surrounded by a mem- brane. The organelles carry out cellular processes just as a person’s pancreas, heart, and other organs carry out a person’s life processes. Eukaryotic cells are generally much larger than prokary- otic cells, as seen in Figure 4-8, which shows a white blood cell (eukaryote) destroying tiny bacterial cells (prokaryotes).

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