Answer the following question given this paragraph: The energy for photosynthesis comes from light. Without light energy, photosynthesis cannot occur. As you can see in the Figure below , plants can get the energy they need for photosynthesis from either sunlight or artificial light. Q: What is the source of energy for photosynthesis? Choices: - air - gravity - carbon - light A:
light
(Question)
Answer the following question given this paragraph: RNA analysis is performed to study gene expression patterns in cells. RNA is naturally very unstable because RNAses are commonly present in nature and very difficult to inactivate. Similar to DNA, RNA extraction involves the use of various buffers and enzymes to inactivate macromolecules and preserve the RNA. Gel Electrophoresis Because nucleic acids are negatively charged ions at neutral or basic pH in an aqueous environment, they can be mobilized by an electric field. Gel electrophoresis is a technique used to separate molecules on the basis of size, using this charge. The nucleic acids can be separated as whole chromosomes or fragments. The nucleic acids are loaded into a slot near the negative electrode of a semisolid, porous gel matrix and pulled toward the positive electrode at the opposite end of the gel. Smaller molecules move through the pores in the gel faster than larger molecules; this difference in the rate of migration separates the fragments on the basis of size. There are molecular weight standard samples that can be run alongside the molecules to provide a size comparison. Nucleic acids in a gel matrix can be observed using various fluorescent or colored dyes. Distinct nucleic acid fragments appear as bands at specific distances from the top of the gel (the negative electrode end) on the basis of their size (Figure 17.4). A mixture of genomic DNA fragments of varying sizes appear as a long smear, whereas uncut genomic DNA is usually too large to run through the gel and forms a single large band at the top of the gel. Q: What type of analysis is performed to study gene expression patterns in cells? Choices: - dna analysis - proteins analysis - residues analysis - rna analysis A:
(Answer)
rna analysis
Ques: Answer the following question given this paragraph: A warm-air heating system uses thermal energy to heat air. It then forces the warm air through a system of ducts. You can see a diagram of this type of heating system in Figure below . Typically, the air is heated in a furnace that burns natural gas or heating oil. When the air is warm, a fan blows it through the ducts and out through vents that are located in each room. Warm air blowing out of a vent moves across the room, pushing cold air out of the way. The cold air enters an intake vent on the opposite side of the room and returns to the furnace with the help of another fan. In the furnace, the cold air is heated, and the cycle repeats. Q: A warm-air heating system uses what kind of energy to heat air? Choices: - atmospheric - nuclear - cosmic - thermal A:
Ans: thermal
(Q).
Answer the following question given this paragraph: Specialized cells may be organized into tissues. A tissue is a group of cells of the same kind that performs the same function. For example, muscle cells are organized into muscle tissue. The function of muscle tissue is to contract in order to move the body or its parts. Q: What do you call a group of cells of the same kind that performs the same function? Choices: - nucleus - molecule - organ system - tissue A:
(A).
tissue
Ques:Answer the following question given this paragraph: Metals such as iron are useful for many purposes because of their unique properties. For example, they can conduct electricity and bend without breaking. However, pure metals may be less useful than mixtures of metals with other elements. For example, adding a little carbon to iron makes it much stronger. This mixture is called steel. Steel is so strong that it can hold up huge bridges, like the one pictured above. Steel is also used to make skyscrapers, cargo ships, cars, and trains. Steel is an example of an alloy. Q: Adding carbon to iron makes what type of metal? Choices: - ions - titanium - plastic - steel A:

Ans:steel
Answer the following question given this paragraph: Mesophyll makes up most of the leaf's interior. This is where photosynthesis occurs. Mesophyll consists mainly of parenchymal cells with chloroplasts. Q: What consists mainly of parenchymal cells with chloroplasts? Choices: - periosteum - chlorophyll - mitochondria - mesophyll A:
mesophyll