Q: Answer the following question given this paragraph: The spleen is in the upper abdomen. It filters pathogens and worn out red blood cells from the blood, and then lymphocytes in the spleen destroy them. Q: What filters pathogens and worn out red blood cells from the blood? A: | OPTIONS:
- the bladder
- the stomach
- the pancreas
- the spleen
A: the spleen

Q: Answer the following question given this paragraph: 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. Q: Silencing genes through epigenetic mechanisms is commonly practiced on what type of uncontrolled cells? A: | OPTIONS:
- giving cells
- neutral cells
- innoculous cells
- cancer cells
A: cancer cells

Q: Answer the following question given this paragraph: 20.2 Ohm's Law: Resistance and Simple Circuits What drives current? We can think of various devicessuch as batteries, generators, wall outlets, and so onwhich are necessary to maintain a current. All such devices create a potential difference and are loosely referred to as voltage sources. When a voltage source is connected to a conductor, it applies a potential difference V that creates an electric field. The electric field in turn exerts force on charges, causing current. Q: Potential differences from various voltage sources are necessary in order to create electrical fields, which result in what flow of charge? A: | OPTIONS:
- voltage
- output
- wattage
- current
A: current

Q: Answer the following question given this paragraph: All chemical reactions need energy to get started. Even reactions that release energy need a boost of energy in order to begin. The energy needed to start a chemical reaction is called activation energy . Activation energy is like the push a child needs to start going down a playground slide. The push gives the child enough energy to start moving, but once she starts, she keeps moving without being pushed again. Activation energy is illustrated in Figure below . Q: What is the amount of energy required to begin a chemical reaction known as? A: | OPTIONS:
- decomposition energy
- reaction energy
- positive energy
- activation energy
A: activation energy