Why is the appearance of the creature significant?

Notice the wording that Victor uses when describing the creature just after it has come to life. He is struck by its physical horror, which he apparently did not notice up until this point. He has chosen to patch together the body parts of multiple men in order to create his new "man," but the combination of all these beautiful parts has only made for a monstrous whole. He is so overcome by horror at the ugliness of his creature, and how frightening its appearance is, that he overlooks the fact that he has just accomplished something that no other person ever has, bringing something back from the dead. As a result, Victor considers the entire experiment a dismal failure...based solely on the creature's looks.
Sadly, the physical appearance of the creature makes such a negative first impression that Victor, the very person who put together this body to begin with, wants nothing to do with him and shuns the creature. This reaction is then shared by every other person the creature encounters. They are so frightened by his physical appearance, they do not take the opportunity to get to know him.
https://www.owleyes.org/text/frankenstein/read/chapter-v

what announcement does Ruth make to the rest of the family?

Mama has suspected it for some time, but in Act I Scene ii Ruth finally confirms that she is indeed pregnant. Mama is overjoyed at the news, but Ruth and Beneatha are much less sanguine. They're thinking about the financial and emotional strain that will be placed on the family by an extra mouth to feed. There is a clear generational gap in the differing reactions of the three women. Mama is very much of the old school; she sees the imminent patter of tiny feet as an unalloyed good. Ruth and Beneatha, however, have a more modern outlook on things. Straight away, they're thinking of the practicalities involved in raising a child in such a cramped, impoverished environment. Far from being a bundle of joy, Ruth's unborn child looks set to be a major burden on the family.

Who is Jabez Wilson?

Jabez Wilson is one of Sir Arthur Conan Doyle's most interesting and memorable characters. He is comical and serious, dumb and sharp, active and lethargic, well dressed and slovenly. His involvement in the actual crime is only incidental, yet he and his shop and his cellar, and his assistant, and his greed, and his defensive pride are all-important to the outcome of the story. This is probably why the author directs such close attention to Wilson's appearance. Both Holmes and Watson look him over and draw conclusions about him. For example, Watson says:

I did not gain very much, however, by my inspection. Our visitor bore every mark of being an average commonplace British tradesman, obese, pompous, and slow. He wore rather baggy grey shepherd's check trousers, a not over-clean black frock-coat, unbuttoned in the front, and a drab waistcoat with a heavy brassy Albert chain, and a square pierced bit of metal dangling down as an ornament. A frayed top-hat and a faded brown overcoat with a wrinkled velvet collar lay upon a chair beside him. Altogether, look as I would, there was nothing remarkable about the man save his blazing red head, and the expression of extreme chagrin and discontent upon his features.

Jabez Wilson's main contribution to the story is that his character makes the preposterous concept of a "League of Red-Headed Men" seem believable. Doyle had to sell that concept to the reader in order for the rest of his story to work. Wilson himself explains that he was very suspicious of the institution from the beginning. His assistant Vincent Spaulding had to talk him into going down to apply for a position and then had to keep him from getting discouraged by the large number of other applicants and push him up the stairs and right into the office of his henchman, who also had red hair and called himself Duncan Ross. Even after Wilson had been hired, he still had misgivings.

Well, I thought over the matter all day, and by evening I was in low spirits again; for I had quite persuaded myself that the whole affair must be some great hoax or fraud, though what its object might be I could not imagine. It seemed altogether past belief that anyone could make such a will, or that they would pay such a sum for doing anything so simple as copying out the Encyclopaedia Britannica.

Doyle is assuaging his reader's skepticism. Once Wilson is assured and has started working, the reader is assured as well.
Sherlock Holmes was a gold mine for his creator. The great detective was featured in four novels and fifty-six stories. He was famous on both sides of the Atlantic. Doyle was one of the highest-paid writers of his time. But he was canny enough to realize that he needed variety. He couldn't just write stories about upper-class types who had some delicate problem and were willing to pay a lot of money for help. Doyle realized that by depicting his detective as a man who cared little about money and everything about exercising his mental powers, he could introduce a whole spectrum of characters and settings from top to bottom of English society.
Jabez Wilson is a good example of a client who has a problem but can't afford to pay the high fee a professional like Holmes would deserve. Wilson only netted about thirty pounds from his work at the League, and he doesn't want to part with any of it. He tells Holmes:

I did not wish to lose such a place without a struggle, so, as I had heard that you were good enough to give advice to poor folk who were in need of it, I came right away to you.

This is very important. It helps to establish that Holmes is good enough to give advice to poorer people. Many of the other Sherlock Holmes stories will get started by the arrival at Baker Street of a man or woman who needs help but can't afford to pay for it. A good example is the impetuous arrival of Helen Stoner in "The Adventure of the Speckled Band." Holmes often helps young women in distress. In another story, "The Adventure of the Copper Beeches," Holmes assists a young governess named Violet Hunter, and in "The Adventure of the Solitary Cyclist," Holmes saves the honor of an attractive young woman named Violet Smith. None of these clients can afford to pay Holmes for his services, and all of them have the common denominator of taking Holmes and his friend Watson to different picturesque places, sometimes clear out of the city. In "The Red-Headed League," the reader is given a detailed description of the neighborhood surrounding Wilson's pawnshop. The modern reader enjoys seeing the sights of England and meeting many of England's quaint Victorian characters.

Why would The Adventures of Tom Sawyer have such an effect on a first-time reader?

The character development in Twain's novel is extremely well done and realistic. Tom Sawyer is funny and likeable, and you can't help rooting for the rascal during all his schemes. Although the town in which Tom lives is fictional, it provides readers with an interesting look into life in the Midwestern US in the 1840's. Whether the reader is an older child or an adult, Tom's preteen antics, his lady troubles, and the Injun Joe plot line are entertaining. Twain's novel is a classic due to the timelessness of its characters and themes. More than any other work of American literature, The Adventures of Tom Sawyer established America's vision of childhood. Times have undeniably changed, but so many elements of the novel—Tom's boredom of school, his strong friendship with Huck, the freedom of youth—remain parts of life that children can relate to and adults can remember as they read.

What does the scientist mean when he says that white blood cells would not be “fast enough or smart enough if we hadn’t whipped them along by a prior immunization”?

To rephrase your question, I think you're asking "Why does immunization increase the speed and effectiveness of clearing an infection?"
Immunization is the process by which exposure to a small amount of pathogen (virus or bacteria) protects from future infection. To immunize against a particular infection, you are given a vaccine. The following critical steps happen when you receive a vaccine and are successfully immunized.
1. B-Cells (a type of white blood cell) start creating antibodies to the infection. The first time you encounter a pathogen, the type of antibody you create (IgM) is less effective at triggering an immune response than the antibody you create every time after (IgG). Additionally, this switch from low- to high-effectiveness antibodies can take anywhere from days up to a week. With immunization, the body "remembers" the IgG it made before and can mount a better immune response faster (see step 4).
2. In some cases, your body also activates T cells (a type of white blood cell), which are responsible for clearing intracellular infections like viruses.
3. The activated T cells or antibody-producing B cells expand, and as they expand, their DNA replication is slightly error-prone. This error-prone replication helps the white blood cells select for better and better binding to the immunized pathogen.
4. After the small amount of pathogen delivered in the vaccine is cleared, your body creates special types of white cells known as "memory B cells" and "memory T cells." These cells are how your body remembers it was previously infected with that particular pathogen. When you encounter a pathogen a second time, these memory cells help activate the immune system faster and stronger than before.
In summary, immunization helps your immune system respond faster to a second infection through 1) Helping create effective antibodies and T cells to the immunized pathogen and 2) forming memory T and B cells, which quickly reactivate the immune system.
I've included a link to a diagram detailing this process below.
https://www.newhealthadvisor.org/Primary-Immune-Response.html

Identify the political ideas of the Communist Party and the NAACP. Explain how the mobilization for World War II impacted African Americans.

The Communist Party holds a Marxist worldview concerning the relationship between workers and capital owners. The main idea is that capital works to concentrate itself and, in so doing, requires continual exploitation of workers and increasing inequality of wealth. This, according to the Marxist worldview, will inevitably lead to the workers rising against the capital owners. The Communist Party in most countries works to hasten this result in a nonviolent manner. The political platform involves nationalizing most (if not all) industries in order to confiscate the profits from capital. Combined with a confiscatory income and wealth tax and a heavily expanded social welfare program, the Communist Party seeks to equalize outcomes for most—though there is a good amount of disagreement about whether complete equality or relative equality is the best course of action.
The NAACP pushes a political view of racial equality, mostly for African Americans. The equality desired by the NAACP is not equality of outcome, but equality of opportunity. Specifically, the organization seeks legislation and court decisions which help to mitigate the damage caused by racism in prior generations in order to create a level competitive field.
Mobilization for World War II brought many African Americans into the military and provided training that might not otherwise have been attainable. Various GI benefits also provided advantages that were not normally available to African Americans.

What is Huxley's satirical purpose in Brave New World? How does he accomplish it, and what is the reader's response?

Huxley is satirizing several trends in early twentieth-century society—trends that are still with us today. First, he is satirizing conditioning people so that they can be controlled. In Brave New World this is done by the state. Humans are subjected to nighttime conditioning from an early age—in some cases, this includes loud noises and electric shocks—so that they will be happy in the place in society to which they have been assigned. This parallels conditioning in our own society, for example, how incessant advertising conditions us to consume.
Second, the novel satirizes the ease with which people can be seduced into giving up their freedom in return for consumer goods and pleasure. The people in the World State are conditioned to endless consumption as well as endless sociality and to mindless pleasures, like the orgies that substitute for religion—they are a different form of "communion."
All of this distracts the masses from the fact that their lives are utterly conditioned and controlled. They are dehumanized by being discouraged from any independent thought, any time alone (which is seen as socially deviant), any deep relationships, and any interaction with great art or literature or even with real science. People in this world seem happy to trade in all the highest and most deeply satisfying aspects of life for security and avoidance of suffering. Mond notes that after the Nine Years' War, people craved security far more than freedom.
Huxley achieves a picture of this society by portraying a world of mindless people popping soma every time they are upset and spending their time at inane pornographic "feelies." He portrays it through Lenina's complete inability to understand John the Savage and through showing us glimpses of all parts of this society from birth to death. He also portrays it through conversations Mond has with people like John the Savage.
Our response is expected to be laughter—the novel is at moments actually funny—but also to be disgust. Huxley expects us to reject living in such an inane and unfree society and to examine how our own culture may also be infantilizing us through consumer goods and vacuous entertainment—perhaps much like social media.