Answer the following question given this paragraph: Solar cells convert the energy in sunlight to electrical energy. They contain a material such as silicon that absorbs light energy and gives off electrons. The electrons flow and create electric current. Figure below and the animation at the URL below show how a solar cell uses light energy to produce electric current and power a light bulb. Many calculators and other devices are also powered by solar cells. Q: What do solar cells convert the energy in sunlight into? Choices: - free energy - experimental energy - subsequent energy - electrical energy A:
electrical energy
(Question)
Answer the following question given this paragraph: Q: The contents of which organ are mixed every 20 seconds? Choices: - the metabolism - pancreas - kidney - the stomach A:
(Answer)
the stomach
Ques: Answer the following question given this paragraph: Populations may show different patterns of growth. The growth pattern depends partly on the conditions under which a population lives. Two common growth patterns are exponential growth and logistic growth. Both are represented in Figure below . Q: What are 2 common growth patterns of population? Choices: - migratory and logistic - exponential and economical - organic and inorganic - exponential and logistic A:
Ans: exponential and logistic
(Q).
Answer the following question given this paragraph: The double helical nature of DNA, together with the findings of Chargaff, demonstrated the base-pairing nature of the bases. Adenine always pairs with thymine, and guanine always pairs with cytosine ( Figure below ). Because of this complementary nature of DNA, the bases on one strand determine the bases on the other strand. These complementary base pairs explain why the amounts of guanine and cytosine are present in equal amounts, as are the amounts of adenine and thymine. Adenine and guanine are known as purines . These bases consist of two ring structures. Purines make up one of the two groups of nitrogenous bases. Thymine and cytosine are pyrimidines , which have just one ring structure. By having a purine always combine with a pyrimidine in the DNA double helix, the distance between the two sugar-phosphate backbones is constant, maintaining the uniform shape of the DNA molecule. Q: What distinctive configuration of dna demonstrates the base-pairing nature of the bases? Choices: - single helix - double loop - triple helix - double helix A:
(A).
double helix
Ques:Answer the following question given this paragraph: If an ore is deep below Earth's surface it may be too expensive to remove all the rock above it. These deposits are taken by underground mining. Underground mines can be very deep. The deepest gold mine in South Africa is more than 3,700 m deep (that is more than 2 miles)! There are various methods of underground mining. Underground mining is more expensive than surface mining. Tunnels must be blasted into the rock so that miners and equipment can get to the ore. Underground mining is dangerous work. Fresh air and lights must be brought in to the tunnels for the miners. The miners breathe in lots of particles and dust while they are underground. The ore is drilled, blasted, or cut away from the surrounding rock and taken out of the tunnels. Sometimes there are explosions as ore is being drilled or blasted. This can lead to a mine collapse. Miners may be hurt or killed in a mining accident. Q: In what type of mining must tunnels be blasted into the rock so that miners and equipment can get to the ore? Choices: - open-pit mining - strip mining - gold mining - underground mining A:

Ans:underground mining
Answer the following question given this paragraph: Cardiac muscle undergoes aerobic respiration patterns, primarily metabolizing lipids and carbohydrates. Myoglobin, lipids, and glycogen are all stored within the cytoplasm. Cardiac muscle cells undergo twitch-type contractions with long refractory periods followed by brief relaxation periods. The relaxation is essential so the heart can fill with blood for the next cycle. The refractory period is very long to prevent the possibility of tetany, a condition in which muscle remains involuntarily contracted. In the heart, tetany is not compatible with life, since it would prevent the heart from pumping blood. Q: What kind of muscle cells undergo twitch-type contractions with long refractory periods followed by brief relaxation periods, allowing the heart to fill with blood for the next cycle? Choices: - nervous muscle - skeletal muscle - smooth muscle - cardiac muscle A:
cardiac muscle