Answer the following question given this paragraph: Solar cells convert the energy in sunlight to electrical energy. Solar cells are also called photovoltaic (PV) cells because they use light ( photo- ) to produce voltage ( -voltaic ). Solar cells contain a material such as silicon that absorbs light energy. The energy knocks electrons loose so they can flow freely and produce a difference in electric potential energy, or voltage. The flow of electrons creates electric current. Solar cells have positive and negative contacts, like the terminals in chemical cells. If the contacts are connected with wire, current flows from the negative to positive contact. The Figure below and following URL show how a solar cell works. http://www. suntreksolar. com/solarElectricity/howCellsWork. asp. Q: Solar cells convert the energy in sunlight to what type of energy? Choices: - active energy - radical energy - stellar energy - electrical energy A:
electrical energy
Answer the following question given this paragraph: Besides the four parts listed above, many cells also have a nucleus. The nucleus of a cell is a structure enclosed by a membrane that contains most of the cell's DNA. Cells are classified in two major groups based on whether or not they have a nucleus. The two groups are prokaryotic cells and eukaryotic cells. Q: What structure of a cell is enclosed by a membrane and contains most of the cell's dna? Choices: - vacuole - ribosome - epidermis - nucleus A:
nucleus
Q: Answer the following question given this paragraph: The Nose and its Adjacent Structures The major entrance and exit for the respiratory system is through the nose. When discussing the nose, it is helpful to divide it into two major sections: the external nose, and the nasal cavity or internal nose. The external nose consists of the surface and skeletal structures that result in the outward appearance of the nose and contribute to its numerous functions (Figure 22.3). The root is the region of the nose located between the eyebrows. The bridge is the part of the nose that connects the root to the rest of the nose. The dorsum nasi is the length of the nose. The apex is the tip of the nose. On either side of the apex, the nostrils are formed by the alae (singular = ala). An ala is a cartilaginous structure that forms the lateral side of each naris (plural = nares), or nostril opening. The philtrum is the concave surface that connects the apex of the nose to the upper lip. Q: The major entrance and exit for the respiratory system is which facial orifice? Choices: - pore - ear - mouth - nose A:
A: nose
Question: Answer the following question given this paragraph: Humans have 23 pairs of chromosomes in each body cell. Q: How many pairs of chromosomes are there? Choices: - 17 - 2 - 13 - 23 A:
Answer: 23
*Question*
Answer the following question given this paragraph: 24.2 Production of Electromagnetic Waves Electromagnetic waves are created by oscillating charges (which radiate whenever accelerated) and have the same frequency as the oscillation. Since the electric and magnetic fields in most electromagnetic waves are perpendicular to the direction in which the wave moves, it is ordinarily a transverse wave. The strengths of the electric and magnetic parts of the wave are related by. Q: What are electromagnetic waves created by? Choices: - Static Charges - gravitational charges - particle charges - oscillating charges A:
**Answer**
oscillating charges
(Q).
Answer the following question given this paragraph: Note Sometimes the word pure is added to substance, but this is not absolutely necessary. By definition, any single substance is pure. The smallest part of an element that maintains the identity of that element is called an atom. Atoms are extremely tiny; to make a line 1 inch long, you would need 217 million iron atoms. The smallest part of a compound that maintains the identity of that compound is called a molecule. Molecules are composed of atoms that are attached together and behave as a unit. Scientists usually work with millions and millions of atoms and molecules at a time. When a scientist is working with large numbers of atoms or molecules at a time, the scientist is studying the macroscopic view of the universe. However, scientists can also describe chemical events on the level of individual atoms or molecules, which is referred to as the microscopic viewpoint. We will see examples of Saylor URL: http://www. saylor. org/books. Q: The smallest part of an element that maintains the identity of that element is called what? Choices: - lattice - nucleus - neutron - atom A:
(A).
atom