Answer the following question given this paragraph: Prokaryotic versus Eukaryotic Gene Expression To understand how gene expression is regulated, we must first understand how a gene codes for a functional protein in a cell. The process occurs in both prokaryotic and eukaryotic cells, just in slightly different manners. Prokaryotic organisms are single-celled organisms that lack a cell nucleus, and their DNA therefore floats freely in the cell cytoplasm. To synthesize a protein, the processes of transcription and translation occur almost simultaneously. When the resulting protein is no longer needed, transcription stops. As a result, the primary method to control what type of protein and how much of each protein is expressed in a prokaryotic cell is the regulation of DNA transcription. All of the subsequent steps occur automatically. When more protein is required, more transcription occurs. Therefore, in prokaryotic cells, the control of gene expression is mostly at the transcriptional level. Eukaryotic cells, in contrast, have intracellular organelles that add to their complexity. In eukaryotic cells, the DNA is contained inside the cell's nucleus and there it is transcribed into RNA. The newly synthesized RNA is then transported out of the nucleus into the cytoplasm, where ribosomes translate the RNA into protein. The processes of transcription and translation are physically separated by the nuclear membrane; transcription occurs only within the nucleus, and translation occurs only outside the nucleus in the cytoplasm. The regulation of gene expression can occur at all stages of the process (Figure 16.2). Regulation may occur when the DNA is uncoiled and loosened from nucleosomes to bind transcription factors ( epigenetic level), when the RNA is transcribed (transcriptional level), when the RNA is processed and exported to the cytoplasm after it is transcribed ( post-transcriptional level), when the RNA is translated into protein (translational level), or after the protein has been made ( post-translational level). Q: If you find dna floating in a cell's cytoplasm, what kind of organism is it? Choices: - unicellular - xerophytic - eurocratic - prokaryotic A:
prokaryotic
Answer the following question given this paragraph: A third factor that affects the rate of dissolving is the size of solute particles. For a given amount of solute, smaller particles have greater surface area. With greater surface area, there can be more contact between particles of solute and solvent. For example, if you put granulated sugar in a glass of iced tea, it will dissolve more quickly than the same amount of sugar in a cube (see Figure below ). That's because all those tiny particles of granulated sugar have greater total surface area than a single sugar cube. Q: For a given amount of solute, do smaller particles have a greater or lesser surface area? Choices: - lesser - equal - neither - greater A:
greater
Q: Answer the following question given this paragraph: Aerobic respiration begins with the entry of the product of glycolysis, pyruvate, into the mitochondria. For each initial glucose molecules, two pyruvate molecules will enter the mitochondria. Pyruvate, however, is not the molecule that enters the Krebs cycle. Prior to entry into this cycle, pyruvate must be converted into a 2-carbon acetyl-CoenzymeA (acetyl-CoA) unit. The conversion of pyruvate into acetyl-CoA is referred to as the pyruvate dehydrogenase reaction. It is catalyzed by the pyruvate dehydrogenase complex. This process produces one NADH electron carrier while releasing a CO 2 molecule. This step is also known as the link reaction or transition step, as it links glycolysis and the Krebs cycle. Of course, as two pyruvates result from glycolysis, two acetyl-CoAs are produced as are 2 NADH molecules. Q: For each initial glucose molecules, two pyruvate molecules will enter where? Choices: - the plasma - the nucleus - Golgi apparatus - the mitochondria A:
A: the mitochondria
Question: Answer the following question given this paragraph: Q: Fission is a method of what type of reproduction exhibited by some planarians? Choices: - spawning - sexual - propagation - asexual A:
Answer: asexual
*Question*
Answer the following question given this paragraph: If a solute is a gas, increasing the temperature decreases its solubility. For example, less carbon dioxide can dissolve in warm water than in cold water. Q: In which kind of water can less carbon dioxide dissolve? Choices: - cool water - tap water - salt water - warm water A:
**Answer**
warm water
(Q).
Answer the following question given this paragraph: The most important way that humans communicate is with language. Language is the use of symbols to communicate. In human languages, the symbols are words. Words may stand for things, people, actions, feelings, or ideas. By combining words in sentences, language can be used to express very complex thoughts. Q: What is the most important way that humans communicate? Choices: - inheritance - painting - instinct - language A:
(A).
language