Q: What is the atomic number? Read this paragraph and choose the correct option from the provided answers: In the modern periodic table, elements are organized by atomic number. The atomic number is the number of protons in an atom of an element. This number is unique for each element, so it seems like an obvious way to organize the elements. (Mendeleev used atomic mass instead of atomic number because protons had not yet been discovered when he made his table. ) In the modern table, atomic number increases from left to right across each period. It also increases from top to bottom within each group. How is this like Mendeleev's table?. Choices: - Number of electrons - Speed of electrons - Number of neutrons - number of protons A:
number of protons

Q: Silencing genes through epigenetic mechanisms is commonly practiced on what type of uncontrolled cells? Read this paragraph and choose the correct option from the provided answers: Cancer and Epigenetic Alterations Silencing genes through epigenetic mechanisms is also very common in cancer cells. There are characteristic modifications to histone proteins and DNA that are associated with silenced genes. In cancer cells, the DNA in the promoter region of silenced genes is methylated on cytosine DNA residues in CpG islands. Histone proteins that surround that region lack the acetylation modification that is present when the genes are expressed in normal cells. This combination of DNA methylation and histone deacetylation (epigenetic modifications that lead to gene silencing) is commonly found in cancer. When these modifications occur, the gene present in that chromosomal region is silenced. Increasingly, scientists understand how epigenetic changes are altered in cancer. Because these changes are temporary and can be reversedfor example, by preventing the action of the histone deacetylase protein that removes acetyl groups, or by DNA methyl transferase enzymes that add methyl groups to cytosines in DNAit is possible to design new drugs and new therapies to take advantage of the reversible nature of these processes. Indeed, many researchers are testing how a silenced gene can be switched back on in a cancer cell to help re-establish normal growth patterns. Genes involved in the development of many other illnesses, ranging from allergies to inflammation to autism, are thought to be regulated by epigenetic mechanisms. As our knowledge of how genes are controlled deepens, new ways to treat diseases like cancer will emerge. Choices: - giving cells - neutral cells - innoculous cells - cancer cells A:
cancer cells

Q: Q: Covalent solutes separate into what when dissolved? Read this paragraph and choose the correct option from the provided answers: Ionic solutes separate into individual ions when they dissolve. Covalent solutes separate into individual molecules. Choices: - second molecules - new molecules - true molecules - individual molecules A:
A: individual molecules

Question: Q: What is the process of moving air into and out of the lungs called? Read this paragraph and choose the correct option from the provided answers: Respiration begins with ventilation, the process of moving air into and out of the lungs. Gas exchange in the lungs takes place in across the thin walls of pulmonary arteries in tiny air sacs called alveoli. Oxygenated blood is transported by the circulatory system from lungs to tissues throughout the body. Gas exchange between blood and body cells occurs across the walls of peripheral capillaries. Choices: - naturalization - hydration - insulation - ventilation A:
Answer: ventilation

*Question*
Q: What makes up the mass number of an atom? Read this paragraph and choose the correct option from the provided answers: The mass number is the number of protons plus the number of neutrons in an atom. For example, most atoms of helium have 2 neutrons, so their mass number is 2 + 2 = 4. This mass number means that an atom of helium has a mass of about 4 amu. Choices: - electrons and neutrons - atoms and neutrons - molecules and electrons - protons and neutrons A:
**Answer**
protons and neutrons

Q: Q: Alveolar ducts and broncioles are developing parts of what organ system? Read this paragraph and choose the correct option from the provided answers: Weeks 1624 Once the respiratory bronchioles form, further development includes extensive vascularization, or the development of the blood vessels, as well as the formation of alveolar ducts and alveolar precursors. At about week 19, the respiratory bronchioles have formed. In addition, cells lining the respiratory structures begin to differentiate to form type I and type II pneumocytes. Once type II cells have differentiated, they begin to secrete small amounts of pulmonary surfactant. Around week 20, fetal breathing movements may begin. Choices: - nervous - immune - digestive - respiratory A:
A: respiratory